Before you hire a Concrete Contractor, you need to decide what specifics you need. First, you should know that you must have general liability insurance to protect your home. This insurance will cover you in the event of any accidents or damage to the property. In addition, you should make sure that your contractor has workers’ compensation insurance in case someone gets injured while on the job. Finally, it would help to ask for a written guarantee of their work. Concrete Contractors  ensure quality services by keeping you updated throughout the project. 

The job of a concrete contractor includes building surfaces and structures. Demand for such professionals is high, and they earn a high salary. The main part of the job is to choose the right type of concrete for the project and the correct application technique. For example, a swimming pool’s best concrete is different from a basketball court. If you need a pool surface, you need a water-resistant compound. Then, you need to find the right mix of cement for a pool surface.

Another important job of a Concrete Contractor is to clean the construction site. A company that has a good reputation will clean up all debris from the construction site. They will also make sure the ground is level and compacted. Lastly, they will remove all trash and debris from the work area. If you have a construction site that requires a lot of debris, the contractor will need to clear it before starting work.

The best contractors will also have a good knowledge of the process of backfilling, removing debris, and leveling the ground. They will know the proper way to do this, ensuring that the finished project will be as seamless as possible. A good contractor will be able to estimate the project’s total cost and track its progress so that they can stay on schedule. The software will also help ensure that the work crew follows the timeline and avoid mistakes that compromise the structure.

A good contractor should be licensed to perform the job. In addition to this, the contractor should be insured to protect their property. A business owner should check and double-check their references and make sure they are honest and trustworthy. The best contractors will also offer you references. You should not hire a Concrete Contractor if they cannot provide references. A good contractor will be able to offer you a reference that can serve as your reference.

A good concrete contractor will keep you updated with the progress of the project. The contractor will need to notify the supervisor and other contractors to avoid any delays. The concrete contractor should not perform any other work until the job is complete. If the contractor has a client, they should communicate with the customer about the progress. A successful one will always be on time and be efficient in their work. If they do not, they should not be hired. In addition, a good job will ensure that you are able to keep up with all the requirements of the job.

An ideal candidate will have experience in a particular field. They will know about the latest developments and trends in the construction industry. They will also be aware of the limitations of their business. They will know what to charge for their services, as well as the scope of their work. They will also have the ability to make the necessary changes. A good contractor will not turn down a job because of its size. Instead, he will only work on the project as long as he is willing to follow the specifications set by the customer.

A successful concrete contractor will keep other contractors and supervisors up to date. The project should be completed in the specified time frame, or it will fall behind schedule. A good job in the field requires attention and careful planning, especially in the early phases. A good worker will be able to provide timely updates and communicate with the construction crew at all times. A profitable concrete contractor will communicate with his clients throughout the entire project.

You can do some basic water heater repairs yourself. The most common and inexpensive problem is a broken heating element. If the component is damaged, you can replace it. The pressure relief valve and thermostat also need to be replaced. If you find rust or fractures, you should hire Plumber  to perform the work. However, if you’re unsure of whether to do the repair yourself or hire a professional, it’s best to get a professional to do it.

A water heater’s maintenance is essential to maintain its efficiency. Often, the heater will be used only a few times before it needs repair. If you’re unsure of the exact problem, you should call a professional. The cost of water heater repair will depend on the issue and the type of home you have. For example, if your water heater is solar-powered, you’ll need to contact a plumber. The repair will be more expensive than fixing a gas-powered water heater. The technician will inspect the system and try to determine what’s causing the leak.

Many manufacturers issue a standard warranty for water heaters. A professional plumber will know how to handle these warranties, so it’s important to get them done by a licensed plumber. This way, you’ll be sure to get your money’s worth if the repair doesn’t solve your problem. A plumber will also be able to tell you if the issue qualifies for a warranty claim. If it doesn’t, you’ll have to pay for it out of your own pocket, which can be a hassle if you’re not sure where to turn.

Whether it’s a simple problem like a leaking valve or a severe corroded interior, you can call a plumber to refresh it for as little as $200. Depending on the extent of the damage, you may need to replace the entire tank, which can cost up to a few hundred dollars. A water heater flushing is a simple procedure that will clear the sediment inside the tank and improve its efficiency and performance.

You should also be aware of the causes of a water heater’s malfunction. A leak can cause serious damage to your home if it is not fixed. If it’s a small leak, you can try to diagnose the problem yourself by checking the tank for loose bolts or holes in the unit. If you’re not confident with the process, call a plumber to take a look at the problem. If the problem isn’t minor, call a licensed expert to take a look.

If the problem isn’t a simple repair, a professional plumber can assess the problem and fix the problem for you. You can also check if the heater is under warranty. Most plumbers know what types of water heaters can be repaired under warranty and can help you determine the best one for your home. They will be able to help you find the right type of repair for your situation. So, before hiring a plumbing professional, ask for their references.

You should also know the type of water heater you have in your home. Different types of water heaters have different strengths and weaknesses, so it is vital to know what kind of model you have. If the heater is making noises, you should check the thermostat. These can be the cause of the problem. You can also replace the anode rod yourself if it’s damaged. A good plumbing company should be able to repair it for you at no additional cost.

Water heater repair is a big deal if you’re experiencing leaks, temperature problems, or water discoloration. If you’re a DIY type of person, you can probably do some repairs yourself. First, check for loose bolts and check if the tank is properly connected. If you’re unsure, you can always call a professional plumber to diagnose the problem and get a free quote. If you’re unsure, you should consider getting a free estimate from different plumbing companies.

Despite the fact that a water heater repair can be a complex process, it’s best to let a professional do the work for you. It’s a complicated task that requires specialized tools and specialized knowledge. Even a small leak can be dangerous. To prevent a serious water heater repair emergency, you should consult a plumber as soon as possible. If you’re unsure of the problem, you can also do some simple preventative maintenance to prevent a water heater replacement from becoming more costly than it has to be.

You can save yourself a lot of money on patio repair by performing a thorough inspection of the damage on your patio. A homeowner can quickly repair cracks and holes in the concrete slab. Some cracks and holes, however, may indicate a more severe problem. In such cases, you can consider resurfacing your concrete patio. However, you should be aware that forcing the resurfacing material into small cracks can be tricky, so you should hire a professional.

Fortunately, the repair process is relatively easy and can save you a lot of money. The first step in repairing Concrete Patio is cleaning the area with a scrubbing brush or paintable crack filler. Once the surface is clean, you can use the patching material to cover the area. Once the patching mix has dried, you can apply it using a caulk gun or a trowel. To repair a crack in the concrete, ensure that the area is clean and free of standing water.

When performing concrete patio repair, you should pay attention to the weather. It is better to perform the repair on a cool day than a hot one because hot weather will increase dust and hamper the proper drying of the parched area. The same applies for the time of day. It is best to perform the repair on a cool day so the mixture can dry properly. If the sun is strong, you should cover the area with a tarp.

Another method of concrete patio repair is mudjacking. This involves mixing concrete mix with soil on your property and using it to lift the slab. Although this process is a bit messy, it is also cheaper and easier to handle. This technique, however, will require a lot of time to cure and is not a DIY solution. A concrete mudjacking project will not make your patio usable for days, and it can also cause your slab to tilt.

If you’re looking to repair your concrete patio, there are several methods available. Some of them can be DIY-friendly, while others may require professional help. The cost of most concrete patio repairs depends on the size of your patio. A concrete mudjacking job can cost anywhere from $50 to $880 per square foot. Depending on the size of the cracks, this process may cost as little as three to five hours. The process is quick and easy, and the result will be a great concrete surface for your patio.

While slab jacking requires a professional to do the work, you can do it yourself at home for a fraction of the price. If you don’t have a professional, you can ask your home improvement store for recommendations. You can also try to look for discounts on concrete slab repair by consulting with Home Owners Associations. Aside from that, you can even save about $3,500 by completing the work yourself. A concrete patio is one of the most important parts of your house, so make sure to have it repaired regularly.

If you are not able to afford a professional patio repair, you can opt for a DIY solution. These options can be very inexpensive and will leave your patio looking great. You can also try repairing your concrete patio yourself if it has cracks in the slab. Depending on the severity of the damage, it may be necessary to call a home repair service to do the job. There are a variety of different DIY solutions for concrete patio repairs.

Another option for repairing your concrete patio is to drill a few small holes in the slab. This will enable you to see the damage, and choose the best solution. You will not need any professional help. Whether you’re confident in your DIY skills or prefer to hire a professional, a DIY project is easy and affordable. It is also a great way to prevent more expensive replacements in the future. So, consider your concrete patio repair options and make it a beautiful part of your house.

Whether you want to repair a concrete patio or replace it, the best way to avoid spending a lot of money is to contact a professional. A professional will be able to diagnose the problems on your patio, and recommend the right solution for your needs. The cost of replacing a concrete patio can be high, especially if the damage is extensive. A replacement will require a lot of work and will need to be completed in an extremely short period of time.

You may just see concrete as a flooring option that is a pretty standard arrangement, one that places tend to opt for if they can’t think of a better choice. But some noteworthy reasons make concrete a great choice for flooring, it can elevate a stepping space to the next level… Let us take a look at 6 great benefits of concrete flooring and how it can transform the look of your property.

Strength 

If you know anything about the strengths of concrete, you will know that it’s a very durable mixture indeed. We’re talking about a material that can withstand very high volumes of weight, with strong pressure presenting no issues whatsoever. Heavy equipment and vehicles would not be enough to make a dent on a concrete floor. So a concrete floor can easily take all the foot traffic and moving of furniture that the average household is likely to take part in regularly without any issues!

Long-lasting

This durability means that the concrete will hold up and last for years to come. Especially if the concrete flooring is well looked after and sealed, you can expect it to last for a very long period before it becomes anywhere near being worn down. And even when the texture and colour begin to change with age, a long way down the line, that adds a bit of ‘character’ to the style of the flooring and is not a practical issue unless it actually becomes damaged in any respects.

Plenty of design options

Concrete does seem to be stereotyped as a boring flooring type, but that is quite unfair. Designers have come up with a wide range of options, with absolutely loads of different colour and textual effects to choose from. And don’t forget you can stain or paint the surface of concrete for your desired effects and also opt for other specialities such as polished concretes.

Reasonable 

If you’re cost-conscious, whether you’re looking to purchase domestic concrete or require flooring for office space, it remains one of the more economical options available. The clever aspect is that you can choose a faux floor pattern that resembles the style of a much more expensive flooring type for a fraction of the cost.

Easy to Maintain

Another big benefit of concrete is that it’s very easy to maintain. As mentioned, it will keep even better with a seal of some kind, a protective sealant that should be reapplied every 3-9 months on average. Regular sweeping and mopping will help keep the concrete looking fresh and new, but other than that, not much maintenance is required. Polishing your concrete is also a great way to keep it looking its best.

Good for Indoor and Outdoor

A final benefit of concrete flooring is it’s a reliable choice for both indoors and outdoors, so you can have it set up in your home or garden area.

You should enjoy selecting a great looking concrete flooring style, but there is also an alternative option. Consider hiring a mini concrete mixer which for a very small daily fee can produce your required amounts of concrete from the comfort of your garden! This can work out to be a very affordable way of getting the job done! So, for all your concrete needs, contact Base Concrete today on 01442 389105. For more details, visit our contact page.

The post Why Concrete is a Great Choice for Floors first appeared on Base Concrete.

Where would we be without concrete? It’s one of the most versatile and essential products for almost all construction projects across the world. It’s a substance that fills our world and can be seen in almost everything we see, but also one that is so easily overlooked.

There are so many uses for concrete. Its applications and uses are more varied and more widespread than you can imagine. There are over 20 different types of concrete that are used in a multitude of construction projects, but what are the most popular applications for it? What is it that makes concrete such an advantageous material to use, and how is it used in both domestic and commercial developments. Let’s take a look.

Origins of Concrete

Concrete, in one form or another, has been with us since 6500 BC. It can be traced back to what is now, the United Arab Emirates, where Nabataea traders created concrete floors, houses and even underground cisterns.

The Egyptians were using it to build the pyramids in 3000 BC, where they used mortars of lime and gypsum to create their version of cement. It was also used, not surprisingly perhaps, to help construct the Great Wall of China. It didn’t become concrete, at least what we recognise it as today, until the 1800s, but since then, its uses have grown more and more.

Buildings

For any of us living in a house or working in a building, it’s likely to be made from brick and mortar to some degree. In the UK, it took off after World War II as part of the rebuilding efforts. Nowadays, it’s probably the most popular application of concrete in the modern age and will be for centuries to come.

Foundation

Even if the building itself is more steel and glass, its foundations will be made from or secured in, concrete. Concrete is so popular because it won’t burn or rot, which means that the foundation is going to maintain its strength and rigidity for many years.

Roads and Bridges

As we move up in the world, the very streets you walk on and the bridges you use to cross those roads will also be made of concrete. Again, concrete wins against other materials because of its durability and safety. It might not be obvious, but another advantage of concrete in these environments is that it offers better reflectivity at night. Of course, it’s not just pedestrians it has to support, but because it can hold heavier weights, such as cars and trucks, it’s the perfect material to use.

Why Concrete has so Many Uses

The applications for concrete don’t stop there. They are only the start. Concrete is so popular in different projects simply because of its adaptability. It’s not sensitive to moisture, can be shaped and moulded into almost any design, affordable and is recyclable.

It has a very long lifespan, doesn’t release any dangerous organic compounds and is just as safe for inhabitants. It’s easy to forget the difference concrete has made to our world, but just look around and you’ll see that it’s everywhere.

Contact Us

Thank you for reading this blog post. Should you be looking for any mixes or perhaps ready mixed concrete itself, then we can deliver it straight to your door. So, if you have any upcoming tasks, then get in touch today on 01442 389105 or visit our contact page for more details.

The post The Many Uses of Concrete first appeared on Base Concrete.

Lots of people fear using concrete. If it goes wrong, it can be difficult to fix, but for smaller domestic jobs it’s actually a lot easier than many people think. With this guide, we’ll go over the different ways to mix concrete so you can decide what’s best for you when attempting your DIY project.

Concrete Proportions

Concrete has 3 main ingredients. Cement, aggregate, and sand. These ingredients are mixed with water, which when dried out, binds into a solid, very hard material. Depending on what you’re using the concrete for, these can be mixed in different proportions to give you different finishes and strengths.

It’s very important to get these proportions correct. With too much sand, your concrete won’t be hard enough to withstand the test of time. However, too much aggregate and you’ll be rushing to find a way to cover it up and pretend that it isn’t there.

Mixing Methods

In a domestic setting, there are several different approaches you can take to mix your concrete. If you’re happy giving the different proportions a go, you can either do this by hand or by using a mixer. For small scale jobs, mixing by hand can be ideal as it’s easy to keep track of the consistency and see how it’s going. This can often be a good thing to do as a practice if this is your first time. For larger jobs, a concrete mixer can save you hours of time and strength mixing larger amounts of concrete together.

When it comes to domestic concrete, it’s often overlooked that there are some other options also available to you, especially for slightly larger jobs such as concrete bases for sheds, summerhouses and other garden accessories. The main differences between domestic and commercial worksites are space. Often with a commercial worksite, the work will be planned to make these processes as efficient as possible, allowing the concrete mixers to reverse right up to where they’re going. However, this doesn’t mean you can’t utilise similar methods.

Types of Concrete Mixers

There are two main different types of concrete mixer. There are ordinary concrete mixers and also volumetric concrete mixers and both of these have different uses. You’ll likely have seen ordinary concrete mixers or mini mixers driving around quite frequently. These have the advantage of being able to transport one of many different mixes of concrete. Extra ingredients can be added to the concrete at the factory in order to provide different properties such as waterproofing or extra fibres for additional strength. However, this isn’t often needed when it comes to domestic concrete.

The other type of concrete mixer is a volumetric concrete mixer. These are ideal for domestic concrete as you don’t need to worry about having too little or too much. ‘Mix as you go’ concrete mixers contain the raw ingredients needed and as you pour out the concrete will mix it straight away. They also have the added advantage over traditional concrete mixers of being able to supply multiple different mixes of concrete to the same job without having to pay the additional cost of bringing in a second load.

Concrete mixers and volumetric concrete mixers are also a great choice for people taking on DIY projects that don’t want to take the risk of getting the mix wrong. All you’ve got to worry about is where it goes with the extra guarantee of knowing that it will stand the test of time. Thank you for reading this blog post. Should you have any enquiries, feel free to call us on 07812 182778 or visit our contact page for more information.

The post How to Mix Concrete by Hand or in a Mixer first appeared on Base Concrete.

How To Seal A Concrete Floor?

Using concrete flooring in your home can be an excellent choice. Especially if you’re interested in the durability of your floor. However, to make a concrete floor last it’s important to seal it properly since concrete is porous.

Sealing a concrete floor is an effective way to keep your floor free of stains from substances such as grease, oil, water, and others. As if that’s not enough, sealed floors look beautiful and are easier to clean.

To ensure that the sealer is effective, however, the application process has to be done properly. Everything you do, from surface preparation to picking the right application tool, will go a long way towards determining the final outcome.

How To Go About Sealing A Concrete Floor

Here’s a quick summary of what you should do when sealing a concrete floor

Clean the floor (remove stains, dust, oil, etc. from the concrete)  Remove any old sealer from the floor Use an etching solution to open up the concrete Use a sprayer or roller to apply the first thin coat of sealer  After the first layer has dried, apply a second coat of sealer in the opposite direction Leave the sealer on the concrete until it dries fully (avoid driving or walking on the concrete until it’s dry)

Cleaning the floor

To avoid inconvenience, you should remove the furniture and everything else from the room. Keep in mind that you will need somewhere to store the items for no less than one week. Once the room is clear, sweep it thoroughly, and then proceed to clean any area that is still dirty.

You can use mineral spirits to clean grease spills. Once the floor looks clean, use a concrete cleaner to ready the floor for sealing. Rinse the cleaner off, and then wait for the floor to dry. At this point, you can use a concrete repair caulk to fill any visible cracks. Then finally, wait until the caulking has dried completely.

Removing the old sealer

If the floor had an old sealant, you have to wait before applying the new sealant. If you’re not sure whether a sealant was used on your floor or not, you can use water to test this. To do this pour approximately one cup of water on the concrete.

If the water does not soak into the floor but instead beads up and remains on the surface, the floor had been sealed. If the floor had not been sealed, the water would soak into the floor. To remove the sealant, you can use a chemical stripper.

Since chemical strippers are acid-based, be sure to protect yourself when removing the sealant. After removing the sealant, you’ll have to let the floor dry for at least 24 hours before proceeding.

Choosing the sealer

There are four main types of sealers to choose from:

•   Acrylic sealers

This kind of sealer sits on top of the floor and is mainly used to seal interior floors. Acrylic sealers are easy to apply, but they don’t protect the floor effectively against grease and oil stains when compared to other sealers.

•   Epoxy sealers

Despite being more durable compared to acrylic sealers, this type of sealer also sits on top of the concrete. Epoxy sealers protect your floor effectively against grease stains, but they are difficult to apply. They are also available in various colors enabling you to change the look of your floor.

•   Polyurethane sealers

This type is mainly meant for use over other types of sealers. Polyurethane sealers have UV protection, which keeps them from turning yellow over time. They also sit on top of the concrete, but the layer is usually thinner.

For this reason, polyurethane sealers are mainly applied over epoxy as the top layer. The sealers are available in semi-gloss, matte, and glossy finishes. Such sealers are typically fine when used over other sealers, but if you’re not sure, you can always get some clarification from the shop you are buying from.

•   Silane/siloxane sealers

You can use this type of sealer if you don’t want to change the look of your floor. Since the sealers penetrate the concrete, it won’t become glossy or darker. It will retain the matte grey color. This kind of sealer lasts 20 years or more and is effective in protecting the floor against stains and deterioration.

pplying the sealant

Here’s what you should do when applying the sealant:

1. Carefully read and understand the instructions

Every sealant is a tad different from the other. For that reason, you should read the manufacturer’s instructions to attain quality results for your project. Be sure to pay attention to important details such as the most appropriate temperature and humidity recommendations for application.

2. Ventilate the room

In whatever room you’re working from, ensure that there is enough ventilation by opening the windows and doors where applicable. You can also use an outside-facing fan to facilitate the movement of air from the room to the outside area.

3. If using an epoxy sealant, mix the two parts together

Epoxy sealants come in two different containers whose content should be mixed before application. In such a case, you should pour the content of the smaller container into the bigger one and then use a stir stick to mix them thoroughly.

You should mix them only if you’re ready to start the application process. It’s also important to note that you’ll have a period of one hour or so to get the epoxy down. For that reason, you have to be quick when working.

4. Divide the room into smaller sections

It’s recommended that you divide the room into four sections for ease of application. You should start with the least accessible section, and work your way out to the door so that you won’t have to walk on the wet sealant.

5. Use a small paintbrush when sealing the edges of the floor

Get a paintbrush that is 5.1 to 7.6 cm wides and use it to apply the sealer along the edges of the concrete floor where the paint pad or rolling brush may not reach. Be sure to use nice, even strokes when applying the sealer.

6. Apply the sealer using a rolling brush or paint pad

Pour some sealant into a painting tray and then dip a roller brush or a paint pad into the paint. If using a roller brush, be sure to roll the brush evenly in the paint. Use the roller brush or paint pad to apply a thin coat of the sealer along the edge that you’ve already painted.

Continue applying the sealer across the floor until you’ve covered the entire floor. When applying the sealer, you should ensure that there is always a wet edge to carry on from. The reason for doing so is to achieve a uniform look on the floor.

Since you’ve already divided the room into smaller sections, you can work on each one of them at its own time. As you apply the sealer, make sure that you spread it evenly across the floor. You should also keep track of your area of coverage to avoid ending up with some patches that haven’t been sealed.

7. Apply a second coat

For a smooth and even finish, you should apply a second thin coat. To ensure better coverage of the sealant across the floor, you should apply the second coat at right angles to the first one. Let the sealer dry as per the time recommended by the manufacturer on the sealant can, before walking or driving on the concrete. You should be ready to wait for up to four days to allow the sealant to dry completely.

Final thought,

Sealing your concrete floors is a foolproof way to increase their lifespan while also enhancing their beauty. The good thing is that you can easily complete a floor sealing project by yourself. If, however, you’re not particularly confident with your DIY skills, you should hire an expert.

If any of our high-quality services interest you, give us a call on 01442 389105 or 07812 182778 today. Or fill out the enquiry form on our contact page for more information.

The post Top Tips To Sealing A Concrete Floor first appeared on Base Concrete.

If you are interested in our kimchi making process, click here to skip to the section about kimchi directly.

Do you ever stop to think about how you’re able to enjoy fresh strawberries, blueberries, and peaches in Winter? Contemporary food systems make an enormous variety of food available at any time of year. Produce travels long distances to be sold where it isn’t in season, undermining the business of small farms and emitting greenhouse gases. Local foods are riper at harvest because of shorter travel times, and choosing to buy local also supports the local economy. But even while shopping local, unseasonal food can be harmful to the environment; energy-intensive food production methods like greenhouses can produce 3-10 times the emissions as imported foods.[1]

Understanding why our food goes bad and what accelerates its decay helps reduce food waste, but fridges are only good at storing fresh produce for relatively short periods. There is a wide range of alternatives to fridge storage that keep fruits and vegetables from rotting for months or even years. This article will detail some long-term storage methods and their benefits depending on region and culinary purposes, and we will take you through our process of fermenting cabbage for kimchi.

When you decide to cut down the carbon emissions of your food, the produce available to you changes seasonally. The good news is that there are ways to store these foods for long periods so that you can still eat and cook with foods after their peak seasons. Alternatives to refrigerating food have existed throughout history, but the availability and convenience of the fridge has brought some of these practices out of the mainstream.

The two categories of traditional, low-tech food preservation are storing food in containers that control temperature and humidity, or preparing food to slow down its decay. 

Storage Methods for Food Preservation

It is important to note that food storage differs in summer and winter because different variables cause food decay in each season. Traditional food storage containers address the needs of produce through passive strategies that make use of the climate.

Zeer Pot

In hot and dry climates, natural fridges make use of evaporative cooling on the outer surface of a clay pot. In this method known as the Zeer Pot, water evaporation converts sensible heat to latent heat. This means that energy is released when liquid water is converted to vapor, reducing the temperature inside the container. The method uses two clay pots, one inside of the other. Between the pots is a layer of sand into which water is poured to begin the evaporative cooling process. Evaporation is continuous, ensuring that the natural fridge stays cool all day, but it relies on an outside temperature hot and dry enough to cause evaporation. Because the Zeer Pot serves the function of a fridge, it does not extend the life of food or preserve it any longer than a fridge, but it is necessary to mention when discussing how to store food without refrigerators or freezers. 

Root clamp using upcycled container

In cool climates and during the Winter months, some vegetables can stay fresh for longer by taking advantage of a steady temperature underground. Root vegetables can avoid frost by being buried, as ground temperatures fluctuate significantly less per day and can stay warmer than the winter air temperature.

Burying vegetables (and some fruits) can be done through covering the planted vegetables with soil or straw, or through harvesting the vegetables and putting them in small underground holes called clamps or silos.[2] Underground food cellars, when available, serve the same purpose. Given that a majority of the world population lives in urban areas, the first option is not as accessible, as it relies on growing your own food in large quantities. The last option, an underground root cellar, is useful for larger quantities of foods and can also be used to extend the shelf life of more than just fruits and vegetables.

Root Cellar

The most accessible of the three ways of burying vegetables is the “clamp” or pits that are completely or partially buried. These can be built relatively quickly using very little garden space and can upcycle used household items (such as washers or steamers). Proper care must be taken to ventilate to avoid mold and to protect the food from rodents or other pests. For protection against rodents, the trench can be lined with rust-resistant metal mesh, which simultaneously aids ventilation. Another method to strengthen ventilation is to place a bundle of twigs in the center of the pit to act as an air shaft. The old drums of washing machines are perforated, which makes them perfect pest protection, but bricks can also be used for the walls and ground of the pit as well. To protect against rain, a plastic sheet can be used to cover the pit, although there may be a problem if the soil around the vegetables becomes extremely saturated from heavy rainfall. 

Root Clamp

Sand storage is helpful to use in tandem with other cold storage methods because it regulates moisture conditions. It can be done at multiple scales, so in large boxes in a root cellar, in a root clamp or food pit, or even at the bottom of your fridge drawer, and it works with all root vegetables, onions, leeks, shallots, and cauliflower.[3] Sand storage entails pouring sand into a container and then submerging the vegetables completely.[4] The sand serves the purpose of a humidity regulator, removing excess moisture, so vegetables cannot be washed before they are stored in this way.[5] Sand storage requires that there be space for ventilation between the vegetables being stored, and the sand container should stay out of heated rooms or areas that are below freezing.[6] If you do not have a food pit, cellar, or food clamp, you can use this method on its own if you have a cold enough garage or, as mentioned above, in the bottom of your fridge drawer.[7]

Preservation Through Food Preparation

Drying

Drying food using a dehydrator, an oven, and the sun

Drying is a method best used for fruit, mushrooms and herbs. It is more easily done during summer because there is more heat and more fruit available to dry, but in the winter, citrus and fungi can be dried in the oven which helps heat the house. Vegetables can also be dried, but they should be blanched, or boiled quickly, before drying, which removes some healthy enzymes.[8] Dried foods retain most of their vitamins, except vitamin C, which degrades quickly.

Foods can be dried in the sun, in an oven, or in a dehydrator, making sure to allow sufficient space for ventilation. The process of drying takes several hours, but it is very hands-off, as most of the work involved is preparing the food by slicing it and putting it on drying trays. When using the oven, care should be taken to set a low enough temperature to avoid burning. Dried fruit is a delicious snack and can be added to baked goods for its flavor and texture. Mushrooms and herbs are multipurpose when dried, and just like dried herbs, mushrooms can be ground to produce a delicious seasoning powder for any meal.

Fermenting

Fermented foods preserve well because the acidic environment blocks bacteria from multiplying. Lactic fermentation is the process in which lactic microbial organisms convert sugars into lactic acid, creating an acidic environment that inhibits bacterial growth.[9] It is best known for making sauerkraut and other cabbage dishes, like kimchi and Salvadorian curtido. Usually the process is to cut vegetables, season them, and leave them in their own juices to ferment for a few days or a few weeks. Then, jars are stored in a cool place—either in a cellar or fridge—and last a year or more. At room temperature, sauerkraut lasts up to a few months,[10] but kimchi will only last about a week if left out.[11] Lactic fermentation allows more raw vegetables to be eaten throughout the year without relying on food travelling long distances. When eaten uncooked, fermented foods preserve their enzyme and vitamin content while adding healthy probiotics.[12] Fermentation adds acidity and a distinct fermented flavor.[13]

Canning and Salting

Canning relies on heat to kill both bacteria and enzymes.[14] Canned food is prepared by placing food in sterilized jars, then boiling the closed jars of food for several minutes to stop factors that cause decay, so the food stays edible almost indefinitely.[15] Canning is an easy process that is helpful for storing foods that will be cooked anyway. However, if we relied on canning to preserve all our food, we would miss out on beneficial enzymes and vitamins.

Salting protects food from the multiplication of bacteria because salt draws the moisture out, creating an inhospitable environment.[16] Often, salted food is rinsed before it is used for cooking, which reduces the sodium but, unfortunately, removes some of the nutritional value from water-soluble vitamins.[17] To work around this disadvantage, salting is best used if the preserved food is intended to be cooked with a high amount of salt, such as in broth, or simply consumed in small quantities.[18]

Our Approach

Every method for storing food in the long-term has specific conditions for which it is ideal. At Critical Concrete, we implemented some of these strategies according to the conditions in Porto.

Local climate is a necessary component of food storage strategies. In the case of Zeer Pots, low humidity is essential to ensure evaporation. As Porto is relatively humid even in the summer, evaporative fridges are not appropriate for keeping food cool in this area. On the other hand, burying produce is optimal in a cool and dry climate.[19] It can even be effective in places that receive snow, as long as certain precautions are taken against moisture.[20] Food preparation for preservation often lasts six months or more. Fermented foods last longer when stored away from sunlight and direct heat, while dried foods need to be stored in a dry environment, such as in dry bags or jars.

Pouring water in the sand layer of our natural fridge to trigger evaporation

In the Summer of 2019 we attempted to build a natural fridge. However, the temperatures inside were not cold enough to store food; on the hottest day, the fridge was 17 degrees, and on cooler days the temperature inside was 13 at the lowest. This is quite logical given Porto’s humid climate, which resulted in less evaporation, and on the warmest day we recorded temperatures, it was only 21 degrees outside. Our unfortunate results emphasize the need for attention to specific climate in storage methods for food preservation.

Kimchi

To look into food preparation methods for long-term storage, we attempted lactic fermentation, using a recipe for vegan kimchi available on the blog Maangchi.com.

We compressed it into the jars to avoid air bubbles. After 5 days fermenting at room temperature, we placed the delicious kimchi in the fridge. (Normally, fermentation at room temperature only occurs for 1-2 days, but we stored it in a very cold unheated room.)

In these before and after images, we can see the evidence of fermentation: there are dozens of air bubbles where, prior to fermentation, we could only see a few. The difference in hue is only due to the artificial lighting used in the first image, however the cabbage is slightly more translucent after fermentation.

Our kimchi turned out wonderfully, but we noticed a few things in the process of making it. First is that it is not shelf stable, relying on the refrigerator to extend the lifetime past a week. (When we build a cool cellar in the Critical Concrete kitchen, the kimchi can be moved there to limit reliance on the fridge.) Secondly, when getting the cabbage ready to ferment, we noticed that the wider jar made it easier (than two other small jars we filled) to pack kimchi without allowing bubbles. Third of all, though slightly minor, is that when preparing kimchi, it is necessary to soak cabbage in brine and then rinse several times to remove the salt. This has the same caveat as preserving food with salt: losing water-soluble nutrients from rinsing. That being said, kimchi makes up for any lost nutrients in probiotics and flavor, and can last more than a year when stored correctly.

Conclusion

When used in the relatively humid summers of Porto, the Zeer Pot technique offered little relief from the hot outside temperatures. In drier climates, it could be a simple and low tech way to expand cold storage or, even better when possible, reduce the need for a fridge. During the winter, burying food is a great way to extend the life of vegetables, although, as mentioned, the reality of urban living makes it difficult to accomplish in many homes. If it is an option, there are many traditional ways to go about it, but each one needs to carefully protect against moisture, cold, and pests.

Salting and canning are two simple methods of food preservation that are perfect for certain dishes, but both affect the nutrient content of food significantly. Dried food offers a wide variety of purposes: in baked goods, as snacks, or as seasoning. As most homes have an oven, it is quite accessible. During the summer it is more energy efficient, but, on the other hand, can help heat your home in winter. The process of fermenting requires very little energy expenditure and can be used for a wide variety of produce, but it is especially suited for vegetables. In fact, as drying can be better for fruits and fungi, and fermenting is great for vegetables, these two methods of preservation complement each other. Although fermentation alters the flavor of raw foods, this can be a benefit. In the case of our homemade kimchi, fermentation was a success. However, it failed to reduce our reliance on the fridge, while still posing some of the problems of salt-preserved food.

Our food culture is built around having every variety of food available constantly, without inspiring consumers to consider where and how that food is produced. There are often significant challenges to eating local, seasonal food, and, at the same time, it won’t solve the world’s problems to only eat such food. However, eating seasonal food when possible leads to more delicious, nutritious meals and helps the environment simultaneously. 

Stay tuned for our next food article in the series, on the use of food scraps.

Sources

[1] Ritchie, Hannah. “You Want to Reduce the Carbon Footprint of Your Food? Focus on What You Eat, Not Whether Your Food Is Local.” Our World in Data, Global Change Data Lab, 24 Jan. 2020, ourworldindata.org/food-choice-vs-eating-local. 

[2] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[3] https://www.gardeningknowhow.com/edible/vegetables/vgen/storing-root-crops-in-sand.htm#:~:text=Root%20veggies%20that%20grow%20vertically,to%20entombing%20them%20in%20sand. accessed 18 February, 2021.

[4] https://www.gardeningknowhow.com/edible/vegetables/vgen/storing-root-crops-in-sand.htm#:~:text=Root%20veggies%20that%20grow%20vertically,to%20entombing%20them%20in%20sand. accessed 18 February, 2021.

[5] https://www.gardeningknowhow.com/edible/vegetables/vgen/storing-root-crops-in-sand.htm#:~:text=Root%20veggies%20that%20grow%20vertically,to%20entombing%20them%20in%20sand. accessed 18 February, 2021.

[6] https://www.gardeningknowhow.com/edible/vegetables/vgen/storing-root-crops-in-sand.htm#:~:text=Root%20veggies%20that%20grow%20vertically,to%20entombing%20them%20in%20sand. accessed 18 February, 2021.

[7] https://www.gardeningknowhow.com/edible/vegetables/vgen/storing-root-crops-in-sand.htm#:~:text=Root%20veggies%20that%20grow%20vertically,to%20entombing%20them%20in%20sand. accessed 18 February, 2021.

[8] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[9] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[10] https://growyourpantry.com/blogs/fermenting-pickling-preserving/how-long-does-sauerkraut-last, accessed 18/01/21.

[11] https://www.healthline.com/nutrition/does-kimchi-go-bad#shelf-life, accessed 18/01/21.

[12]Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[13] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[14] Seymour, John. The Self-Sufficient Gardener: A Complete Guide to Growing and Preserving All Your Own Food. Dolphin, 1980. 

[15] Seymour, John. The Self-Sufficient Gardener: A Complete Guide to Growing and Preserving All Your Own Food. Dolphin, 1980. 

[16] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[17] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[18] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[19] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

[20] Preserving Food without Freezing or Canning: Traditional Techniques Using Salt, Oil, Sugar, Alcohol, Vinegar, Drying, Cold Storage, and Lactic Fermentation. Chelsea Green Pub., 2007. 

The post Knowing our Food: Preservation first appeared on Critical Concrete.

Interested in learning more about this topic and more social and sustainable ways of doing architecture? Apply now for our Postgraduate!

jQuery(function() { _initLayerSlider( ‘#layerslider_20_zvknsy4vfdqj’, {createdWith: ‘6.11.2’, sliderVersion: ‘6.11.2’, skin: ‘v6’, navPrevNext: false, hoverPrevNext: false, navStartStop: false, navButtons: false, showCircleTimer: false, skinsPath: ‘https://criticalconcrete.com/wp-content/plugins/LayerSlider/assets/static/layerslider/skins/’}); });

DISCLAIMER

This article explains how to protect wood from pests, water and fire showing different environmental-friendly techniques

!UPDATE! !UPDATE! !UPDATE! !UPDATE! !UPDATE! !UPDATE! !UPDATE! !UPDATE!

DE BLOWA

UseProtectionLimitationInterior & exterior wood,
termites-infested woodKilling and repelling termites and other pestsIf a change in colour is not appriciated

DE BLOWA is a mixture of proven anti-termite and anti-pest ingredients that we at Critical Concrete used to protect almost all of the wood we use. So far, we haven’t done any long-term research into its effectiveness, but we’re optimistic that it’s a very useful combination because all of the ingredients are individually useful treatments for pests. The name is an abbreviation for the materials it contains:

DEDiatomaceous Earth100 gB
Borax100 gLLinseed Oil3 kgOOrange Oil100 gWAWood Ashes100 g

It is important to shake the mixture well before application, as the ingredients are not dissolving and settling on the bottom of the container. Then the mixture can be easily applied with a brush (or for a larger surface with a paint roller). Users should be aware that DE BLOWA gives the wood a darker shine. If a fine result is required, the excess should be removed a few minutes after brushing with a cloth.

ProTip: If the wood is already infested, it is recommended to briefly pull the wood through fire from all sides to kill the termites. Another option is to inject orange oil into the visible termite tunnels with a syringe. Read more about the single ingredients and techniques in the following article!

Interested in using this technology in your project?

Critical Studio can help!

Learn More!

Introduction

Wood is a versatile and renewable material with a positive carbon footprint, which proves to be a significant construction material in sustainable architecture. Because of its strong and lightweight characteristics and the possibility to be processed and worked easily, it is a good replacement for other, less ecological materials. Additionally, wood is a relatively cheap material and gives any construction a cozy and natural atmosphere.

All these advantages make wood one of our most used materials within our projects. For example, instead of concrete or metal, the heavy load of our green roof is carried by strong wooden laminated beams of 12x48cm. Also, reclaimed wooden windows are giving a unique touch to the backyard facade of our workshop.

Beams carrying the green roof

The facade in process

Despite the mentioned advantages, wood as a building material still faces some persistent prejudices, which can lead people to refrain from using wood in their constructions. Many bacteria, fungi and insects find wood appetizing, and humidity and moisture can lead to its early decay. Besides this, a misconception associates wood with being very flammable and thus, a risky building material (when in fact wood retains its strength longer and at much higher temperatures than steel [1]). So, if wood is prepared and treated in an appropriate way, it can be turned into a long-lasting, water- and bacteria-proof as well as fire resistant building material. Many still-standing examples prove that wooden structures can last over centuries and, taking their time of origin into account, that wood can be protected without any artificial products.

House on the Faroe Islands

When it comes to protecting wood from the mentioned dangers, one can already find a lot of articles on the internet. In this article we avoid the commonly used methods which often involve ingredients harmful to the environment and instead focus on the natural and non-toxic techniques. Besides, we want to promote and facilitate the usage of reclaimed wood. The basics of how to prepare reclaimed wood for the prevention technique can be found at the end of the article.

Based on our experience and research, this article aims to give guidance regarding sustainable and environmentally-friendly techniques to protect wood against pests, humidity and fire. What techniques fit best for your projects can be traced in the decision tree below.

Protection Techniques

Exterior and interior wood are exposed to very different conditions. Whereas both need to stand fire and pest, the wood outside is prone to much more risks as it may have to withstand heavy rain, persistent humidity or high-levels of sunlight radiation. In our projects we usually use applying borax and linseed oil for interior wood and the Japanese technique of charring wood (shou sugi ban) for exterior wood. Depending on the conditions of the property and on the available resources, a combination of techniques may be suitable.

CHARRING WOOD

UseProtectionLimitationExterior and interior wood;
preferably cedar, pine, marble, hemlock or oakagainst humidity
against pests and fungi
enhancing fire-resistance
sunlight-protectionnot suitable for glued and easily cracking wood

Charring Wood is a Japanese technique which originated in the 18th century, known as Shou Sugi Ban. The surface of the wood is burned until carbonation of the surface. The finished result is called Yakisugi. We already published an article about the technique’s history and contemporary use in architecture today, check here.

Counter-intuitively, charring wood has several astonishing advantages without involving any chemicals. The idea is to burn the surface of the wood without combusting the whole piece. Besides giving the material an interesting and unique look, the process lead to a triple protection:

fire protection – this might seem counter-intuitive, but the burning of the surface starts a carbonation of the material and thus lower the thermal conductivity. The treated material will take more time to burn in case of a fire than the regular wood.
termite and mold protection – burning wood destroys the nutritional value to insects and fungi, that regular wood gives to these species. Thus it helps to prevent the propagation of pests.
water protection – the enhanced carbonation gives the charred layer a waterproof resistance, as water slips on burned wood like over an oily surface.

TRADITIONAL STYLE
(suitable for a certain amount of similar boards)

Traditionally the technique is used with Japanese cedar. Cedar is usually the easiest species to burn because of its natural chemical properties and wide grain patterns, making it a more porous wood. In the last few years, the technique has been popularized in western countries and extended to other species of wood like pine, hemlock, maple, or oak. We used pine and beech, but we experienced that these species tend to show cracks when charring. Before burning other species of wood than the ones mentioned above, it is advised to research on previous experiences or make small prototypes. It needs to be mentioned, that once the piece gets charred, it may contract slightly and change its shape as it loses humidity. If working with very precise measurements, this needs to be kept in mind!

Following, the article is highlighting different approaches to do the burning process. For both it is recommended to choose a well-ventilated place, preferably outside, but to avoid breezes. Safety measures should include a nearby fire extinguisher, a bucket of water as well as fire-resistant gloves. Wearing flammable clothes like polyester, sawdust or any flammable items within the close surrounding must be absolutely avoided.

Traditionally in Japan, shou sugi ban is performed by bonding three planks of wood to form a long triangle and starting a fire in the resulting tube. This technique is suitable to char a bigger amount of similar boards (e.g. for cladding). The easiest way to create this triangle is to place the three boards next to each other on the ground with facing the sides to be charred upside and then folding the two outside boards upwards. The triangle can be easily fixed with wire.

One possibility is to put the triangle on a non flammable floor and start the fire at the opening at one side of the triangle. In the best case, the fire spreads over within the whole tube and it will take a few minutes to char the surfaces of the wood. Once the surface is sufficiently burned, the planks are separated and thrown to the ground to stop the burning [2]. The other possibility is to start the fire while the triangle is standing up. Therefore a stable and fire-resistant base (e.g using bricks) is advisable, best next to an also fire-resistant wall. Besides, a fire-resisting spot where the hot and probably still burning triangles can be placed later, needs to be prepared. The wooden triangle can be placed in a slight angle to the wall and the fire can be started inside the lower opening of the triangle. It is also possible to put a grill on the fire-resistant base and start a fire in there, keeping the fire slightly smaller than the hole of the triangle. That way the triangles can be just put on top of the fire and the process will be started. Once the bottom part of the tube catches fire, the fire will make its way to the top. After some minutes fire shoots will be visible on the top and after waiting another minute the triangle can be removed with fire tongs. Once the wood is placed on the prepared spot, the fire can be hosed off with water [3].

As it is can be an unhandy task to fix and loosen the triangles, we are working on a technique to facilitate the process. We are building a burning station, where you can easily put wooden boards and start a fire underneath. When the station will be refined, we will share the methodology and tools in another short article and in a YouTube-Video!

ADAPTED STYLE WITH A HANDHELD BLOW TORCH
(suitable for every form)

If the wood does not come in similar boards or if you do not feel comfortable with the traditional method, the wood can also be charred using a handheld propane blowtorch. For many tasks we worked with this method, for example burning the windows for the facade. Precautions for this method include the mentioned safety measures and the preparation of a fire-resistant spot to place the wood during and after the process.

Starting the process, the torch needs to be lit and the gas opened to the full, so the fire appears more in a bluish colour, meaning it is more concentrated and strong. A good distance between torch and wood lays between 10-15 cm, held in a relatively straight angle. (The distance depends on the torch, but it should be around the right distance when the top of the touching blue fire separates into orange flames).

Burning process with a handheld blow torch

It is recommended to move the torch slowly over the surfaces. In the first seconds, the grains will be highlighted in a darker colour and after the whole surface will turn darker. To get the full protection characteristics, the surfaces should turn completely black and the very first layer should start to get porous. After finishing all the surfaces, the wood needs to cool down.

The burning process

Charred board

FINAL FINISHING FOR CHARRED WOOD
(applicable for traditional and hand torch technique)

After charring the wood, one can clean it softly using a standard wire brush to remove the most superficial char and create a non porous surface, using the brush in the direction of the wood grain. This task needs some precaution. If the wood is brushed too much, its pores will be opened up again and thus the water protection layer might be lost. It is enough if the excess of the burn is removed and the texture of the drains become slightly visible. After the surface can be cleaned with a cloth or water or by using an air compressor. As final coating applying linseed oil is recommended (see the advantages of linseed oil more up in the article).

CRITICAL CONCRETE CHARRING STATION
(Shou Sugi Ban without gas)

At Critical Concrete, we wanted to build up a tool with commonly available materials which enables us on the one side to charr wood of different sizes and forms effectively, but on the other hand, keep the process at very little risk and environmentally-friendly. Check out our Video about our very own Shou Sugi Ban Charring Station!

BORAX

UseProtectionLimitationInterior woodagainst pests and fungi
against humiditynot suitable for exterior wood (only combined with another technique or with a weather-proof resistant wood spieces)

Borax Crystals

Borax is composed of naturally occurring minerals that usually comes as a white powder, consisting of soft and colorless crystals that will dissolve in water. The structure of the boron, salt and oxygen molecules inhibit the metabolic processes of many organisms and therefore borax disinfects and kills unwanted pests and insects [4].

Be aware, that even if borax is a completely natural product, it doesn’t mean it is completely safe to manipulate. For sensitive people, contact with borax may lead to skin or eye irritation [5]. Even though borax enhances the woods protection against humidity, borate protections are only suitable for indoor wood that is protected from weather.

To prepare the solution, the mineral needs to be dissolved with water. We experimented on different percentages and concluded that the mix of 10% of Borax and accordingly 90% of water seems to be the most suitable division. When doing the mix, the water should have a temperature of around 40 degrees, so the mineral dissolves faster and in a higher quantity into the water.

Before applying the borax-mix, the wood needs to be cleaned with a wet but tightly squeezed fabric (to prevent the wood from absorbing more water) to remove dust and dirt. Just before putting the borax-water mixture, it has to be stirred again, because the solution will start settling after some time. To ensure not to apply too much water to the wood and to avoid running noses, it is recommended to wipe off any excess liquid of the paintbrush. To guarantee the effect of the borax minerals, a preferably homogeneous coverage is important. The borax must be fixed with a layer of oil, stain, lacquer or wax. (Look at the next step where we explain why and how you should use linseed).

We have to admit that using Borax as a termite repellent is the best solution we found so far, but that from a sustainable point of view it is far from perfect. The biggest and commercially most important sources of Borax are found in California and Turkey; minor resources can be found in Romania, Bolivia, Chile and Tibet. For us in Portugal that means on the one hand long transportation ways and its unsustainable consequences. But on the other hand and probably much worse the exploration of the minerals from deep layers in the earth can cause immense and devastating damage to nature and landscape. For this reason we are investigating alternatives such as wood ash mixes.

ORANGE OIL

UseProtectionLimitationInterior & exterior wood,
termites-infested woodagainst dry wood termites

Besides borax, orange oil has to be proven environmentally friendly repellent. Deriving from the skin of an orange peel it saturates the wood and gives it a shiny appearance. Thus the efficiency of orange oil against termites is debated. Some sources declare that it kills dry wood termites, but it fails to fight subterranean termites [6]. We applied little amounts of orange oil several times in a row to localized termite infections with a serine and in our case orange oil proved to be very effective. Orange oil is expensive (4 liters for around 100 €) but you never need a big quantity. For small surfaces and already infested areas it is a proper substitute for borax.

In our project we also use 5% mix of orange oil with linseed oil to protect our interior wood from future infestation. But bear in mind that if the borax will remain on your wood permanently, the orange oil would probably slowly be absorbed and loose effect with time. To our understanding it works better as a treatment than as a preventive measure.

LINSEED OIL

UseProtectionLimitationInterior & exterior Woodagainst humidity
sunlight-protection

Linseed oil exhibits many advantages and thanks to its non-toxicity and its environmentally-friendly characteristics is coming back into force lately. It can be used inside and outdoors and act as a protection for water and sunlight [7].

It penetrates deep into the wood, so it does not only saturate the surface but the whole piece of wood. It is also suitable to lock the layer of borax. It lends a golden hue to the wood which will turn to amber over time. The colour is a question of taste and due to its long drying time linseed oil may not be everyone’s favorite. But in fact, it is possible to reduce drying time by using double boiled or polymerized linseed oil [8].

Comparison between a beam with and a beam without linseed oil

To apply linseed oil is very easy, a surplus of oil needs to be wiped off from the brush before applying it to the whole wooden surface and after it needs two to three days to be completely absorbed by the wood.

Linseed oil has the advantage that it penetrates relatively deeply into the wood. But it is also possible to replace all the air contained in the wood with linseed oil. The technique uses first a vacuum to cause the air in the wood to be drawn out, followed by pressuring warmed up linseed oil into the wood structure. Once the oil has hardened, the wood cells should be prevented from absorbing any moisture. For now, this technique is common among instrument makers; at Critical Concrete we did not have the chance to experiment with it so far, but we will do in a close future (stay tuned for upcoming articles).

WOOD VACUUM STABILIZATION

Usually, this technique is done by using a sealable container and a vacuum-pump. The container is filled up with linseed oil, some sources recommend a 2:1-mixture of linseed oil and turpentin. One or more wooden pieces are put into the oil, the container is sealed and and the vacuum pump is started, going to a maximum pressure of 90 kPA (for less fragile parts the optimal maximum vacuum pressure needs to be evaluated). The second phase involves compressing the air up to 75 psi and isolating the container. It is recommended to heat the oil to a temperature around 35 degrees to prevent the oil from “boiling”. The whole thing should be left like this for about a day. After, the heating can be turned down and before starting the depression the oil should cool down for a few hours. When everything has cooled down, the pieces can be taken out of the oil. It is necessary to keep the wooden pieces in a cold environment and give them a daily wipe for the following days, as the oil may continue to sweat and thus leaving ugly patches which will later on be hard to remove. After this activity has terminated, the pieces can be removed to a warmer place to speed up the drying process (which can also involve many days). It is still questioned whether this technique is suitable for bigger pieces of wood, as we could only find examples for smaller pieces (as seen in a construction context). It has to be evaluated whether the oil can penetrate completely into big pieces of wood and if yes, if it can also dry completely. Besides making the wood waterproof, the vacuum pressure treatment adds to weight, stability and resilience of the wood [9].

LIME AND WOODEN ASHES

UseProtectionLimitationContact between ground and woodagainst subterranean termitesnot applicable on wood

Both lime and wooden ashes are alkaline, and termites do not prefer alkaline environments. This mixture was already used in ancient China, where it was usually spread on the soil to kill subterranean termites, which can also be helpful to avoid wooden construction to get in contact with termites via the soil [10]. Besides, we found some suggestions to put ashes directly in holes that derive from termites. Also a study from Uganda shows that wooden ashes (sometimes mixed with pepper or cow urine) applied to the trees and soils kept the termites away [11]. For now it seems like it is not directly applicable to wooden surfaces, because the wood’s ph is usually acidic and these of ashes and lime are alkaline. Whenever acidic and alkaline components come into contact and water is present a chemical reaction will occur. It might have been possible to predict the reaction if bringing together only a few inorganic compounds, but wood consists of a multitude of organic compounds which differ even from species to species [12]. Thus, it might be an interesting field to experiment in the future.

DDITIONAL OPTIONS SUPPORTING TERMITE-FREE WOODEN CONSTRUCTIONS

Termite-eating Worms and Fungus. There is also the possibility to attack subterranean termites (which might flow over to wooden constructions) while placing a special species of microscopic worms into the soil next to the construction – Nematodes. They come as parasitic roundworms and they will quickly find and enter the host insect’s body and start eating it from the inside. Doing so, they are releasing gut and the termite will suffer from blood poisoning and quickly die. Nematodes will go on to its next victim till they cannot find any host insect anymore and then die. Similar working species of fungus exist, too [13]. If these worms may have any potential to be put directly into a wooden construction or if they will act as a pest themselves (as for example Bursaphelenchus xylophilus does to pine trees)needs further examination.

Diatomaceous Earth. Consisting of small decayed organisms, which have dried out and become razor sharp cut the sensitive, outer shell membranes of small insects. After the insect’s shell is sliced, the extremely dry particles of the diatomaceous earth actively dehydrate and thus kill the insect in a short time [14]. Diatomaceous Earth is commonly used to kill existing pests by spraying the powder to the infested areas. If and how it is applicable as a preventive protection to be applied to the wood needs to be examined.

Sunlight. Termites might die when they are exposed to sun radiation and heat. So, furniture or pieces of wood which are mobile and where indicators of termite infestation can be indicated, might be without termites after they were put for some time into direct sun [15].

Termite traps. The favorite dish of a termite is cellulose, that is why they are craving for wood and everything which is somehow made out of wood. Cardboard boxes provide an ample amount of cellulose. If the infestation of termites is apprehend, setting out a wettendend cardboard box can lure them out of their hiding. This way will probably not lead to the total extinction of the termites in one place and it needs repetition from time to time, but every termite removed is a good termite [16].

Protective measurements deriving from the construction details

The protection of wood can be enhanced the way it is – installed in the construction. On vertical boards the water can flow more easily and thus will penetrate less into the structure. Another strategy can be to work with a ventilated wood and batten structure, securing a constant ventilation on the exposed wood. This is traditionally used in barns and today adapted to many contemporary wooden construction. If possible, exposed joints, screws and nails should be avoided, reduce possible enter spots for humidity and to obviate rusty spots.

Conclusion

Due to its environmentally-friendly characteristics and its easy-to-work with features, wood is one of the most important materials in our projects. To protect this precious material and to enlarge its usable life-circle, we discovered the mentioned techniques as the most suitable for us. One the one hand, those methods enable the protection of wood with commonly used tools or with very little acquisitions. On the other hand, they not just renounce spreading toxic material into the environment, they also prove that wood can be a durable construction material, which can replace other, less sustainable materials. Nonetheless, those techniques are not exclusive when it comes to sustainable and ecological wood protection techniques, but using these methods set incentive for a more sustainable architecture.

Building the green roof structure

BONUS-TRACK

Depending on if and how the wood was used before, the wood may need to be prepared before applying the protection techniques. This possibly includes cleaning and smoothing the wood.

Notice: Before starting to work with wood, it is important to check the humidity of the wood (max. 20% – it is possible to use hygrometer or by comparing the weight of some size and species of wood). If the wood is too wet, it is not possible to work with it, otherwise all the effort will be in vain, you’ll damage your tools, and the wood is probably highly damaged already.

CLEANING THE WOOD

When using leftover wood, it most probably shows traces of its former life, including left-over nails, screws and other applications as well as old (and probably chipped and multilayered) paint. In case this “vintage style” is wanted, it is important to weigh the aspired look against to what extent the wood needs to be protected. Removing the leftover screws, nails and other applications will facilitate the following steps. To get rid of the paint, we suggest two tools: the classical scraper or a piece of broken glass.

When using the scraper, it is crucial not to use it in a steep angle, even if this may work more efficiently. Instead using it in a shallow angle and trying to get the scraper under the paint to protect the underlying wood from scratches.

Scraping paint by hand

Measuring

A suitable piece of broken glass for this task has a curved side. For some kind of paint, thinner glass may be more efficient, but the thinner the glass is the more likely it is to break. Also it may be more handy when the piece of glass is a bit bigger (around 10-20cm), but depending on its thickness it is also more likely to break.

It may appear that it is easier to do this task without gloves, as it brings more precision in your hands. Before taking off the gloves, changing to more tight-fit gloves can probably solve this issue.

Changing between scraper and different pieces of broken glass, in some areas one or the other may work better. Independently of the chosen tool, the scraping off of old paint can be either an easy task if the paint happens to be brittle and already chipping, or in the worst case it can take hours.

SMOOTHENING THE WOOD

After removing the nails the wood probably looks dirty, but also new wood may also have a layer of dirt, bark or mold covering its surface. It is important to clean the surface well to make the wood receptive to the following wood-protection treatment, for example to ensure a better infiltration of pest-protection and oil. An additional advantage of the removing of the first layers is the beautified appearance of the new wood surface.

The removal of the top layers and smoothing of the surface is achieved by sanding or planing. Of course there is the possibility to sand by hand, but unless it is not a very small wooden surface that you need to be protected, it may be really better work with a sanding machine.

While using the sanding-machine, it is crucial to put the sanding patch or belt as flat as possible on the wooden surface (of course as long as this is manageable with the kind of surface you have). It may appear that it works faster and more efficiently when the sanding paper is touching the wood at an angle. But on the one hand it ruins the result as the surface will not turn out straight and bumps can be easily created. On the other hand, it also ruins the sanding pad at the edges.

Sanding

Little corners, that cannot be reached with the sanding machine – or while using the machine could come close to very weak parts – need to be sanded by hand, or a multi-tool if you have one! The worn out patches of the sanding machine probably can be used for the parts which need to be sanded by hand.

Now the wood is ready for protection!

Sources

[1] NZ WOOD “Which building material performs better in a fire – wood or steel?”, [Online] available at http://www.nzwood.co.nz/faqs/which-building-material-performs-better-in-a-fire-wood-or-steel/ (Last accessed in January 2020)

[2] Shou Sugi Ban “Shou Sugi Ban 101”, [Online] available at http://shousugiban.com/shou-sugi-ban-101/ (Last accessed in January 2020)

[3] Instructables “Backyard Shou Sugi Ban”, [Online] available at https://www.instructables.com/id/Backyard-Shou-Sugi-Ban/ (Last accessed in January 2020)

[4] ThoughtCo “The Chemistry of How Borax Works as a Cleaner (Sodium Borate)”, [Online] available at https://www.thoughtco.com/how-does-borax-clean-607877 (Last accessed in January 2020)

[5] Healtline “Is Borax toxic?”, [Online] available at https://www.healthline.com/health/is-borax-safe#safety (Last accessed in January 2020)

[6] Networx “Does Orange Oil Work for Termites?”, [Online] available at www.networx.com › article › does-orange-oil-work-for-termites (Last accessed in January 2020)

[7] The Craftsmen’s Blog “How To: Use Boiled Linseed Oil (Safely)”, [Online] available at https://thecraftsmanblog.com/how-to-use-boiled-linseed-oil-safely/ (Last accessed in January 2020)

[8] ARDEC “Linseed oil, a natural solution for Wood Finishing”, [Online] available at https://ardec.ca/en/blog/22/linseed-oil-a-natural-solution-for-wood-finishing (Last accessed in January 2020)

[9] Good Bagpipes “Vacuum and pressure oil treatment of wood”, [Online] available at https://www.goodbagpipes.com/index.php/about-me/writings/pipe-making/131-vacuum-and-pressure-oil-treatment-of-wood (Last accessed in February 2020)

[10] Abdalla House “Termite deterrents”, [Online] available at https://www.abdallahhouse.com/2009/11/termite-deterrents.html (Last accessed in January 2020)

[11]P. Kiwuso, G. Maiteki and J. Okorio “Indigenous methods of controlling termites in agroforestry in Uganda”, 2015, Kampala, Uganda

[12] Passivhaus “LA PRESERVATION DES BOIS DANS LA CONSTRUCTION” [Online] available at https://passivhaus.fr/wp-content/uploads/2017/11/traitementsalternatifsdesboisdeconstruction-1.pdf (Last accessed in January 2020)

[13] Varsity termite and pest control “All-Natural Ways of Eliminating Termites” [Online] available at https://varsitytermiteandpestcontrol.com/natural-ways-eliminating-termites/

[14] Citypests “Diatomaceous Earth for Termites”, [Online] available at https://citypests.com/diatomaceous-earth-for-termites/

[15] Pesthow “How to get rid of termites”, [Online] available at https://www.pesthow.com/how-to-get-rid-of-termites/

[16] Pesthow “How to get rid of termites”, [Online] available at https://www.pesthow.com/how-to-get-rid-of-termites/

[image by Vincent van Zeijst], [Online] available at https://commons.wikimedia.org/wiki/File:Faroe_Islands,Streymoy,_Kirkjub%C3%B8ur(1).jpg (Last accessed in January 2020)

The post Natural Wood Protection first appeared on Critical Concrete.
Did you miss our previous article…
https://www.akbarconcreteworks.com/?p=156

Interested in learning more about this topic and more social and sustainable ways of doing architecture? Apply now for our Postgraduate!

DISCLAIMER

[This article shows the development of the first step of a new prototype experimented in Critical Concrete. During the conception of the green roof, the structure was checked by a civil engineer who also advised us in the development of our wildest prototypes.]

Check out the video to see how we experimented with scrap tyres and compressed earth&gravel for a low-impact and concrete free building!

Introduction

In the progress of developing our green roof prototype we have been confronted with foundations in different ways. Seeking for alternatives it turned out that the old granite walls of the building, once reinforced by wooden beams, would be strong enough to carry the load of the new roof. You can read all about the refurbishment and reinforcing of the walls for the roof in our previous articles (walls-refurbishment 1.0, walls-refurbishment 1.1, how to build a stone wall).

The size of the new roof however, stretches out further than the fully loadable walls. For that reason, part of the roof needs a different kind of foundation.

Section of the green roof highlighting the parts supported by tyre foundations

Our Research

Throughout our research for alternatives to concrete, we stumbled over the tyre foundation. For us, it was very interesting since it is a low-tech solution which is composed only of scrap tyres filled with compressed gravel. Both components are easily accessible almost everywhere in the world.

Indeed, when tyres worn out, they become a waste which is not easy to handle. Recently, more processes that aim at recycling have been developed from which rubber, steel and textile fibers are obtained. Another solution is to reuse the tyres directly in a different context, thus avoiding more energy consumption for the transformation of the product.

Pile of trashed tyres

Worn out tyre reused in a new contextScrap tyres have already been tested in various cases in the construction field, for example to make the roadbed of the streets and referred to as mechanical concrete, a method widely used in the USA. One of the most known cases is the Earthship Biotecture concept autonomous houses developed by architect Michael Reynolds, in which earth-rammed automobile tyres are used for building the main retaining wall of the house. This technique is presented as the most appropriate method for its strength, economy and low need of technical skills.

Pictures by mechanicalconcrete.com (pictures on the left) and by earthship_biotecture (licensed under CC BY-NC-ND 2.0) (picture on the right)

The flexibility of the tyre can also offer durable protection in a seismic area. These foundations can indeed reduce the effect of seismic vibrations on the building on top of them and it can be used in every stable soil, even clay soil (for more information click here). Yet we couldn’t find any applications that fits exactly our needs. Many cases used the tyres to build walls, or wall-like foundations where the structure was resting without anchoring. Other examples used conventional concrete to fix some kind of anchoring sockets. As far as we know, our case, a structure with several punctual load bearing columns, has not been well documented yet.

Interested in using this technology in your project?

Critical Studio can help!

Learn More!

Our Approach

In our particular case, we designed two single stepped footings for two columns of the green roof.

Section and plan of the two single stepped footings for two columns of the green roof

One part of the green roof structure lies on a massive, structurally stable granite wall built in the 19th century, and the other part will lay on the new foundation. Since it is a prototype and it is not well known how the foundations will react to the heavy load, we decided to make the new part (15m2) independent of the rest of the roof previously built (120m2). This assembly required us to insert an expansion joint which allows movement due to ground settlement or other variations, expansion or contraction of building materials. It will also assist the observation of potential changes and reduce the risk of damaging the whole roof in the worst case scenario. Indeed, this technique has been used in England for at least 15 years. Research and experiments of the Holy Trinity Church Tulse Hill showed that they tyre stacks will hold a minimum of 1000 kN/m2 of load with no detected movement on the expansion but a compressive variation of only 3mm (to watch the video click here). The IUT of Grenoble made tests of loading tyre foundations from the Flexagone office: They applied the weight of pressure of 72 tons on the foundation, without any damage or detectable movement (for more information click here).

Additionally we consulted several engineers to check our structural conceptions. As we explained in former articles, the heavy loads on the roof – composed of the drainage layer, earth and plants – impacts the renovation process by its load of 600 kg/m2– 5.88kN/m2, including the dynamic load. Based on this information and our needs, we developed the concept of single stepped footings for columns. We calculated that each pillar should carry about 2400kg approximately. The foundation includes a socket which joins it with the wooden column.

Section of the Tyre Foundation

This connection is especially important while setting up the tyre and aligning the structure. Once the roof is finished, its own weight will hold its place. Below the foundation is a metal plate. On one hand, it distributes the forces on the soil and on the other hand it connects the foundation to the holding socket of the column. On top of the metal plate lay the tyres. We chose two tyres to make the foundation strong enough for the load. One truck tyre (95cm ø) and a smaller car tyre (65cm ø). The holding socket for the column is layed on the upper tyre and connected to the foundation through threaded rods which are welded to the base plate. The socket itself also holds the column in the right position.

Our workexplained step-by-step

This guide is an overview of every step we took in building our prototype of the tyre foundation. Since it was our first attempt, not all of our processes are optimized and need further development. However, this should serve as an inspiration for anyone with a similar situation and is open for discussion and improvement.

Beforehand a list of tools we used
in the progress:

welding machine,crowbar,grinder,hammer,wheelbarrow,bench drill,shovel,cutter.

Throughout each phase, we remind you that it’s important to protect yourself using appropriate safety equipment.

For this, you will need:

helmets,protective goggles,appropriate protective gloves,security shoes,reusable dust masks.

Preparation of the ground

The first and most important step before starting any foundation is the analysis of the ground. The soil has to have a sufficient bearing capacity. If the soil is not suitable there are different possibilities like reinforcing the soil, digging deeper, or adapting the foundation type to a wider tyre for example. In our case, we needed to dig until +/- 70 cm under the floor level to find a proper soil. We decided to put a layer of 5 cm of compressed gravel, frequently used under footings to have a correct level.

Estimated time: 6 to 8 hours per pit,
depending on the toughness of the ground

Leveling the ground of the pit

The base metal plate

The metal plate is the base of the foundation and serves as a solid surface for the tyres. We chose a thickness of 2 cm. To have the plate and also the column connected to the foundation we welded 4 threaded rods to the plate. The socket will be attached to these rods later on. Before putting the plate in the pit we put a breathable and waterproof membrane supposed to protect the plate from humidity in the ground. An EPDM membrane might have been a more suitable choice to increase the durability of the protection. We tried to wrap the plate as well as possible. Additionally, we painted the base plate and especially the weld joints with anti-corrosive paint. We still don’t know how this will react with the time, neither if it is going to be efficient enough to protect the welds. Our main objective is to take all the necessary precautions to avoid that water eventually permeates and settles at the bottom of the foundation. In our next tyre foundation build, we would consider drilling some holes in the metal plate to allow for the draining of water infiltration. The use of this metal plate was advised by our engineer to level the ground on which the foundation itself would set, but we didn’t find any other project using a similar precaution. It was also helpful for us to link the column to the foundation on a robust way.

Metal plate wrapped with membrane

Estimated time: 2 to 6 hours,
depending on accessible tools to cut the plate on the good dimensions

Metal plate on the ground of the pit

Preparation of the columns

The columns we used are made out of two 12×24 cm construction plywood beams. To join the two pieces we glued and screwed them together. The section is therefore 24×24 cm. To protect the wood from fire, water and pests we applied a layer of wood ash on the tyre, as well as protected the wooden column with a layer of borax, known as a protection against mold and repellent against insects. For a specific protection to prevent a specific termite attack, we paint the column with a mix of essential orange oil (5%) and linseed oil (95%). We will soon dedicate a detailed article to wood protection from fire, water and pests.

Estimated time: 2 hours.

Preparation of the socket

We used a steel socket to fix the column with the foundation. The socket is connected to the foundation with four threaded rods. It is fundamental to align properly the rods after putting the base plate, so that the columns would be aligned to each other. We used a wooden guide to secure the rods’ position while filling the tires. This guide is composed of two pieces that represent the two plates, with the holes for the threaded rods, and a long bar that helps to maintain them aligned and in place.

Metal plate on the ground of the pit

Estimated time: 4 to 6 hours,
depending on accessible tools to cut the steel and drill the holes.

Checking the alignment

Filling of the tyres

In its rawest form, the tyres can only be filled with earth. Lots of case studies for earth filled tyre foundations are in relatively dry climates where the temperature doesn’t go below 0°C. It is preferable to use an other sub-grade as gravel or other material to encourage drainage and allow for water expansion, and then avoiding some major instability in the ground caused by frost. We decided to choose gravel made of local accessible granite, from the North of Portugal. We had the choice of three sizes of gravel. After some discussions with our engineer, we decided to order the smallest to have better cohesion. We also added some sand to create a mix with better bonding and leave no empty space between the gravel. We used the ratio of two parts gravel to one part of sand (2:1). The mix in the tyres has to be then as compressed as possible. At first, the tyre can be filled with a shovel and by hands. When it is not possible to get any more of the mix in, a crowbar and a piece of wood can be used to open the tyre (see how they did at the Holy Trinity Church Tulse Hill). Once held open, a second person can continue to fill up the space with the mix. A piece of wood can be used to shove the mix in as deep as possible and a hammer to compress it. This needs to be done until the tyre is inflated and no more mix can be added. The foundation is now ready for the socket.

Estimated time: 6 hours for two people to fill the 2 tyres for one foundation
(a truck and a car tyre).

Installation of the socket

The steel socket which is holding the column is made out of three pieces of steel. The objective is to obtain a socket that correctly holds the column. We thought about different forms and finally settled with a “U”-form, that could maintain the feet of the columns and be correctly fixed to the lower part of the foundation.

Base plate

The first part being the base plate (30x30cm), which has four holes to be fixed with the threaded rods of the foundation. The holes of the plate have to line up with the position of the threaded rods and should be 1mm bigger than the diameter of the rods to facilitate their insertion. Our rods were 12mm diameter. The second part being the two steel brackets (15x20cm), which are welded to the plate and hold the column with two horizontal threaded rods. The individual steps of this process are explained below.

(1) The holes in both of the brackets, which should be shifted, can be drilled and should be at least 2-3mm bigger than the rods.

(2) Afterward, the first bracket can be welded on the base plate.

(3) The piece, that results from this step can be used to mark the position of the holes on the wood of the column. For this, half of the steel socket can just be laid on the column.

Image

(4) It might be necessary to cut a little edge of the column so there is some space for the weld. After marking the holes, they can be drilled also 2-3mm bigger than the rod. The bigger the holes are, the more room there is to adjust and compensate for potential inaccuracies.

(5) The next step is to find the right position for the second bracket. For this, the socket can be laid on the floor, and the column can be put on it. The rods can be stuck through the holes of the first bracket, the column and the second bracket, which is not fixed yet. Also, the bolts can be put on and tightened.

Column steel base plate sketch

(6) The second bracket should now touch the base plate and there should be no gap. If it doesn’t, any holes can be drilled bigger to make it fit properly. If it fits, it can be fixed by welding on 4-5 small points. Afterward, the column can be removed. The second bracket should be in the right position and can now be welded on completely.

Estimated time: 5 hoursto install the socket: drill, weld and adjust.

Installation of the columns

Once the socket is welded together in the “U”-form and the holes are drilled, the foundation is ready to receive the columns which have a section of 24×24 cm.Having an even level foundation is crucial and is something to pay extra attention to, during all the process. First, we used the spirit level to check the level of the lower plate, to ensure that the tyre will be placed on level ground. Indeed, it is important to keep in mind that the column will apply a heavy load that needs to be properly transferred to the foundation. For the next steps, the laying of the tyres and the fixation of the socket, make sure to always keep checking the level and the alignment of each foundation.

Checking the level of the metal plate

Estimated time: 2 hours.

Preparing the columns

The retaining wall

In our case, one of the foundations is positioned under the level of the earth, in an outside environment, that forced us to find a solution for the rainwater not entering inside the workshop space. A retaining wall has been constructed to withstand lateral pressure of soil, due to earth and rainwater. There are a lot of different retaining walls, used for different situations for example the gabion retaining wall or the cantilever retaining wall.

Building the retaining wall

In our case, we built a gravity retaining wall that depends on its self-weight only to resist lateral earth pressure. Commonly, this needs to be of large proportions because it requires a significant gravity load. We constructed the wall from granite stones that we had acquired from previous deconstruction of old walls. To protect the column from water infiltration, we bonded the stones with a lime mortar mix.

Furthermore, we plan to realize a drain which prevents rainwater from entering the basement. Parallel to the retaining wall, it will collect excess water and runs it through a pipe into a sump away.

Cost and Time Comparison

Since we are using the tyre foundation instead of a concrete foundation, the comparison of cost is a crucial point. For this reason we compare only the part of the foundation which is replaceable. The socket and the column are therefore not part of the comparison, since they are the same for both versions. We already pointed out the factor of sustainability, which is our driver in this matter. But what does this mean from an economical point of view? A tyre foundation in its simplest form is only made from dirt and scrap tyres and is therefore basically free. This method is suited for retaining walls and foundations that don’t require anchoring. Our Approach of a highly stressed single step footing which includes anchoring cost approximately 125€ compared to the concrete version of approximately 28€. As the calculation shows, the major cost factor is the metal plate which is also an open question for us. Its necessity is not completely clarified wherefore we are looking for alternatives which even out differences in price and make the single step foundation an economically competitive alternative.

It is to be added that the concrete should be mixed homogeneously by a cement mixer rather than by hand, and that welding the steel reinforcement takes some time as well and electricity, and quite a few welding electrodes. In terms of time, the concrete takes at least 7 days to set sufficiently for a foundation in order to set-up the column, but is faster to make, comparatively.

Conclusion

In the process of finishing the green roof, the application of the tyre foundation has been challenging but successful so far. It is carrying the roof structure but needs further observation as to how it will react under the full load of the green roof including soil and vegetation. To be able to observe any kind of movement we installed a measuring unit that we will control regularly.

Movement measurement

Sustainable Satisfaction?

Concrete is an extremely popular material for construction and can be found in most parts of the world. Today concrete is the primary material used for foundations because of its many positive attributes: it is strong in compression, it is flexible as it can be poured into adapted forms and sizes, it can be applied in situ, it has good fire resistant qualities. However, the production of Portland cement, an essential constituent of concrete, leads to the release of significant amounts of CO2 and other greenhouse gases. Because of limited natural resources, such as sand, and the output of greenhouse gases, concrete production is not sustainable and therefore requires alternatives in the construction field. A possibility is to use recycled materials which have low energy costs, high durability and low maintenance requirements and therefore a small impact on the environment.

The single step footing foundation represent a viable and affordable alternative method we are looking forward to developing and using in further projects.

You want to see more? Check out the video to see how we experimented with scrap tyres and compressed earth&gravel for a low-impact and concrete free building!

Sources

[Ar. Bindu agarwal, Ar. Aanchal Sharma] “Reuse of Waste Materials: A case study of Earthships”, in: International Journal of Science, Engineering and Technology Research (IJSETR) Volume 6, Issue 10, October 2017, [Online] available at: http://ijsetr.org/wp-content/uploads/2017/10/IJSETR-VOL-6-ISSUE-10-1364-1369.pdf (Last accessed in December 2019).

[Architecture 2030] “Buildings generate nearly 40% of annual global GHG emissions”, [Online] available at architecture2030.org/buildings_problem_why/ (Last accessed in December 2019).

[Andrew, Robbie M.] “Global CO2 emissions from cement production, 1928–2018”, CICERO Center for International Climate Research, [Online] available at: https://www.earth-syst-sci-data-discuss.net/essd-2019-152/essd-2019-152.pdf (Last accessed December 2019).

[Decorex Pro] “Technology for the construction of the foundation of tires”, [Online] available at: /en.decorexpro.com/fundament/iz-pokryshek/ (Last accessed in December 2019).

[Department for Business, Innovation and Skills London] “Estimating the Amount of CO2 Emissions that the construction industry can influence”, [Online] available at: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/31737/10-1316-estimating-co2-emissions-supporting-low-carbon-igt-report.pdf (Last accessed in December 2019).

[Deva Racusin, Jacob; McArleton, Ace] “The Natural Building Companion: A Comprehensive Guide to Integrative Design and Construction”, 2012

[Flexagon Office] “Fondations et plots”, in: La Maison Ecologique 67 – fevrier et mars 2012, [Online] available at: http://yourtes.net/fichiers/Fondations%20et%20plots%20-%20La%20Maison%20Ecologique%2067%20-%20fevrier%20et
%20mars%202012.pdf (Last accessed in December 2019)

[Holy Trinity Tulse Hill on YouTube] “Packing Car Tyre Foundations (Car Tyre Foundations #4)”, [Online] available at: https://www.youtube.com/watch?v=0YV2TG5aypw (Last accessed in December 2019)

[Holy Trinity Tulse Hill on YouTube] “Car Tyre Foundations Plate Test”, [Online] available at: https://www.youtube.com/watch?v=K8Vlz6qNCfU (Last accessed in December 2019)

[König, H., Weissenfeld, P.] “Entretien écologique du bois”, ed. La plage, 2008.

[Lowimpact] “Why cement should never be used with natural buildings”, [Online] available at: https://www.lowimpact.org/why-cement-should-never-be-used-on-straw-bale-houses/ (Last accessed in December 2019).

[Mechanical Concrete] “Award Winning, Economical, Green, Industrial Strength, Construction Technology”, [Online] available at: http://www.mechanicalconcrete.com/ (Last accessed in December 2019]

[Miteco] “Descarbonatac fabrical”, [Online] available at: https://www.miteco.gob.es/es/calidad-y-evaluacion-ambiental/temas/sistema-espanol-de-inventario-sei-/040614-descarbonatac-fabric-cal_tcm30-429852.pdf [Last accessed in December 2019)

[Miteco] “Combust fabricamento”, [Online] available at: https://www.miteco.gob.es/es/calidad-y-evaluacion-ambiental/temas/sistema-espanol-de-inventario-sei-/030311-combust-fabric-cemento_tcm30-430164.pdf (Last accessed in December 2019)

[Naik, Tarun R.] “Sustainability of Concrete Construction”, [Online] available at: https://ascelibrary.org/doi/abs/10.1061/%28ASCE%291084-0680%282008%2913%3A2%2898%29 (Last accessed in December 2019).

[Russian Patents] “Module-type anti-seismic protective unit for buildings and structures”, [Online] available at: https://russianpatents.com/patent/225/2250308.html (Last accessed in December 2019]

[World Green Building Council] “New report: the building and construction sector can reach net zero carbon emissions by 2050”, [Online] available at: ww.worldgbc.org/news-media/WorldGBC-embodied-carbon-report-published (Last accessed in December 2019).

The post Tyre Foundations first appeared on Critical Concrete.