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DISCLAIMER

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

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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.thevisualconcretegroup.com/?p=250

Cork forests

Portugal is not only known for good wine and beautiful beaches, it is also the largest producer of cork, more than 50% of the world supply comes from this country, before Spain, Morocco and Algeria.

Map of the location of montado © APCOR

Natural cork originates from of the bark of the cork oak tree (Quercus Suber), which is indigenous to the Mediterranean region and northern Africa. The first harvest of a tree can be made after approximately 25 years and the bark renews itself naturally every 9 to 12 years. The cork oak forests in Portugal, called Montados are an important contribution to the biodiversity and balance in the ecosystem. The cork is present throughout the country, but especially in the Algarve and the Alentejo plains, and occupies 22% of the country’s forest area.

It is important to preserve these forests, because it is home to a number of mammals, reptiles, birds as well as the Iberian lynx, the world’s most endangered feline species. The montados are part of the Portuguese cultural heritage and contribute to the regional identity.

Properties and uses

Cork has some remarkable qualities and can be used for many different purposes, it is even applied in space as thermal insulator for space shuttles. It is light, durable, elastic, waterproof, fire retardant and has great insulation properties. Furthermore, it is 100% reusable. The structure is composed out of tiny gas-filled cells, creating a huge disproportion between the volume and the weight of the material, more than half of its volume is air.

These properties make cork incredibly useful as a building material, whether as flooring, insulation sheets or surface finish. The cork can have different shapes: insulation panels, coatings flooring, cork stoppers, composite agglomerates, raw material. 

If the material is used raw and 100% natural (if the process is free from chemical substances), it can provide an ecological alternative to conventional solutions, not least because of the barks ability to absorb CO2 during the regeneration process. Regularly harvested cork trees store 3 to 5 times more CO2 than those left unharvested.

THE PRODUCTION PROCESS OF CORK INSULATION

Working mainly on architectural projects in the North of Portugal and looking for a local material to integrate a vernacular approach, we were interested in the potential use of cork in construction.

We recently had the opportunity to use this wonderful material in two important projects and with different applications. In this article, we will describe the cork applications we tested and the methodology we used.

Like all our research, we paid attention to have the most sustainable applications with: relatively low cost, simple process and possibility to re-use the cork panels.

ADVANTAGES OF CORK INSULATION100% natural and fully recyclableExcellent thermal and acoustic insulationEasy to apply ( However, cork is fragile)Mechanical stabilityGreat behavior in large temp. range (-180ºC to +120ºC)CO2 sink (Carbon Negative)

INSULATION WALLS AND ROOFS WITH CORKS

The walls

Currently, we are finishing the renovation of a modest house for a family as a part of our Post-Graduation in Sustainable Architecture, in partnership with the municipality of Esposende.

In order to improve ceiling height and spatial quality, the roof was taken off and made new. We used the opportunity to insulate the new roof and built an exterior insulation system on the walls that had none. Like many buildings in Portugal, the Esposende house did not have any insulation .

The challenge was to find an economic and ecological solution to improve this. In the case of the rehabilitation, we faced a series of challenges:

The walls were far from being anything close to straight.We wanted to avoid the glues and mortars that are very often used in cork solutions in architecture (like in the ETICS system).

 Aerial view of the wall insulation system

So we used this cork insulation system:

1. Regularize the walls a bit, enough to limit protuberances from the wall from the line we aspired to follow.

2. Setup vertical supports on the wall, starting from the edges, following three horizontal thread lines, in order to transform a twisted wall into a straight support for our system. To protect the wood, we have applied a mix of natural oils (Read more about natural wood protection in this article)and have placed 5 cm stone wedges under the wood to avoid any contact with the floor and prevent it from rotting. Between each of these posts will come the 5 cm layer of cork.

3. Cover the walls with a first layer (1 cm) of cork, below our vertical supports fixing them with screws and wall plugs directly in the wall. A thin board is better to fit the shape of the walls without leaving empty spaces. This layer is thought to prevent thermal bridges between the 5cm layer of corks coming next. For this reason, the two layers should overlap in a tile fashion.

4. Superpose another cork panel of 5 cm on the first board and between the vertical battens. Making sure to have continuous overlap between the two layers. 

5. Fix horizontal structure on the vertical ones every 40-50cm from each other to hold the cork panels (5cm). These horizontal support will allow a wedge to sit between themselves and the 5cm cork boards, to secure the ventilation of the system and pressure the cork boards together and bear the board and batten system.

6. Set up the board and batten system on top of the horizontal structure set up in point. Depending on the wood you’re using, avoid putting two screws horizontally on the boards to avoid cracking. The boards should be free of movement and have at most one or two nail/screws set up on the vertical plane. The battens are the one pressuring the boards in place.

The roof

For the roof, we optimized the use of material to ensure the most sustainable application, as with the walls. Thus, we only used four layers: corkpanels, vapour barrier, wood and finally roof tiles. We used a corkboard of 8cm with overlapping joints to secure the potential thermal bridges. The cork boards used for the roof are overlapping to avoid thermal bridges. From the original 1000*500*40mm boards, the manufacturer cuts out 40mm on two perpendicular sides to allow the overlap. 

We decided to follow the sarking technique. The sarking method allows us to have a continuous and homogeneous insulation, without thermal bridges due to the frame.

And internally we benefit from the timber structure that can be seen inside the house!

Roof insulation system

Here are the different steps: 

Lay the cork board directly on the rafters. We used very thick cork panels to avoid using OSB as a roof support. These panels made of sheets of resinous wood assembled by a synthetic resin have the defect of not being very breathable. Cover the cork panels with a vapor barrier, this material is used for waterproofing to prevent interstitial condensation of the roof and finally to allow eventual humidity to go out. Grid the roof with vertical and horizontal battens. They will serve as a support for the tiles and will allow a complete ventilation of the roof. Set up the tiles.

GREEN ROOF WOTH INSULATIVE CORKBOARD WITH INTEGRATED DRAINAGE SYSTEM

We decided to use cork for another architecture project last year, a sustainable green roof. A vegetal roof of 140 square meters covering all the top of the workshop. In this article, we will only explain why and how we used the cork, but if you want to learn step by step how to build a green roof, we advise you to watch this video. 

We used cork for a triple goal: insulation, drainage and water retention, in partnership with Neoturf, who investigated this possibility and designed the board. The grid on the top side of the board was meticulously designed to allow for a high flow of water drainage. It is necessary for a roof to withstand frequent torrential dumpers and by using this system, we negate the need for synthetic insulation and plastic drainage cups.

These cork boards provide insulation with a thermal efficiency of 0,038 à 0,040 W/mK* on average, which is comparable with material with synthetic sources such as expanded polystyrene.

On the top, to protect the cork from the plant’s roots and substrate a geotextile is added to prevent silt and other particles from the substrate from clogging the grid drainage system within the cork. Activated clay balls surround the borders of the walls, windows, and wooden barriers, and provide additional drainage and fire protection.

The post BUILDING WITH CORK appeared first on Critical Concrete.

After three years of research, design and construction, our 130 square meter roof is finally finished! 

We are happy to share with you an overview of all the steps we went through, the sustainable technologies we integrated into this project, and the impact we think green roofs can have on our urban landscapes. 

Watch the video below for an explainer of the process of constructing our ecological green roof: 

This journey started three years ago with the demolition of the old roof and replacement with a glulam structure. Along the way we integrated several sustainable technologies that we have documented with articles and videos. For instance, we used recycled tyres for the foundations of our wooden wall structure and protected the exterior timber facade using our charring technique inspired in the traditional japanese process of Yakisugi. 

For more information about these researches, check our previous articles here.

CHARRING STATION

TYRE FOUNDATION

Green roofs are often proposed as a solution to the lack of green space in urban environments or as a way of slowing down the flow of water. But do conventional green roofs actually deliver on these claims? Our research of modern green roofs found that the materials used in construction often do not align with the sustainability ethos that a green roof proclaims. We sought to find alternatives to plastic filters, insulation, and drainage systems: the materials that typically make up the layers of a green roof. In our mission to adopt low-tech, sustainable architecture and construction techniques we wanted to reduce material consumption and also make it as easy to replicate and apply in other situations as possible.

Our green roof layers

Green Roof detail

EPDM

Laying EPDM around rooflights

EPDM Silicone

We needed a waterproof layer to cover the OSB roof layer and protect from water ingress. We chose EPDM, a synthetic rubber, due to its availability and long life span. 

Geotextile

To protect the cork from the plant roots and the substrate a geotextile layer is needed. This prevents silt and other fine particles from clogging the grid drainage system within the cork. Geotextiles are semi permeable fabrics that help separate soil layers but permit the passage of fluids. 

Irrigation System

For the climate we enjoy here in Porto an irrigation system is definitely not necessary. However in order to control the parameters of Neoturf’s experiment a system was installed. In the future we will build a rainwater harvesting system that will allow us to store and re-use rainwater for non potable purposes. Watch this space!

Cork Insulation

Cork grid

Laying the cork panels

The most cutting edge element of this design is the inclusion of cork insulation, thanks to a partnership with Neoturf, who conducted the research about this design. This is the first time this design and technology has been implemented on a green roof of this size so we are very excited and hopeful for the results. The expanded cork is a by-product of the industrial process for manufacturing wine corks and is being increasingly used in construction. We explain more about this carbon negative wonder material in a full article here. 

Cork is a carbon negative material as the trees it is harvested from absorb CO2 from the atmosphere as they grow. These cork boards provide insulation – with the thermal efficiency of Lambda 0.038-0.040 watts per meter kelvin or R3.6/inch.In cold months this is comparable to synthetic materials such as expanded polystyrene during warm weather synthetic insulation performs very poorly due to having low thermal mass [1].  Additionally, in order to allow water to drain a grid was pre-cut into the panels: vital to withstand Porto’s frequent downpours. By using this design and material we negate the need for synthetic insulation, plastic drainage cups, and other plastic liners. 

Substrates

The second experimental aspect of our green roof is being investigated in partnership with Neoturf, who specialise in landscape design and nature based solutions. The soil that is used on green roofs cannot be composed of simply hummus. It requires other gravels or materials that reduce compaction and promote effective drainage. Neoturf are investigating how well 3 different substrates that use recycled construction waste perform in contrast to the commercially available alternative. Should this research prove successful they will promote the widespread use of recycled waste as substrate across the industry. Over the next two years they will monitor the progress of the plants growing on our roof. 

Interview with Paolo Palha from Neoturf

Check out an in-depth interview with Paolo Palha, researcher and engineer from Neoturf, that gives us insights into the significance of his research and what they are expecting to find in the next couple of years, monitoring the plants’ growth:

Conclusion

This green roof represents three years of hard work, prototype development, and teamwork. Countless hands have helped repair walls, build structure, haul earth and the thousands of other tasks needed to realise this ambitious project. We send huge love and thanks to everyone who has helped in any way. This is a major milestone for us and we are excited to see our plants grow healthy and strong. Neoturf will continue with this research over the next two years, after which we can adapt the roof to grow our own food and reach a higher level of self-sustainability.

Are you interested in implementing an ecological green roof in your project? Critical Concrete can provide advice, design and construction services for the whole process: including structure, procurement and material sourcing. Contact our studio today!

Interested in using this technology in your project?

Critical Studio can help!

Learn More!

We need your support to continue researching and developing ecological, low tech solutions. Check out our patreon to see what perks we offer in return for helping us on our sustainable mission.

The post How to make green roofs really green? first appeared on Critical Concrete.
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Researching new methods of wood protection are of key importance for the work we do here at Critical Concrete. Wood is the primary material we use to build and renovate houses; from the structure, to the cladding, and the furniture. Priorities of our wood protection solutions include; relatively low-cost, accessible materials, simple recipes. Prioritising these aspects means it is easy to scale up for large projects. 

Tricoil

For our renovation project in Esposende, we rebuilt the roof with a wooden structure, so it was essential to protect the wood for the longevity of the building. With the cladding substructure, window lintel, and furniture we had a lot of wood to treat. Through research of various recipes we came up with a recipe and method which fit the requirements we had. 

TRICOIL (Turpentine/Tung Raw Linseed I Coconut OIL or 3 oil) is a blend of three different oils which gives protection from parasites and environmental conditions. Linseed oil, Tung oil, and Coconut oil are blended together using turpentine as a solvent to combine the oils and allow for deeper penetration of tricoil into the wood. The original recipe and method we based this upon can be found here [1]. 

Tung oil has been used by the Chinese for hundreds of years to protect wooden boats. It is derived from pressing the nuts of the Tung tree. It has anti-termitic properties and offers durable waterproofing. 

Raw Linseed oil, obtained from pressing flax seeds, creates a water repellent barrier on the wood.

Coconut oil, rich in fatty acids, nourishes and protects the wood. 

Turpentine, a solvent derived from tree resin, thins and blends the oils for easy application to the wood. 

Method

Ratio of ingredients for TRICOIL

Heat a large pot of water to 50°C to act as a bain-marie. Place a jar of coconut oil and turpentine into the bain-marie and cook until this mixture has also reached 50°C, stir often. If you have a big enough pot, you can do the same with the linseed oil and tung oil together in one jar, placed in the bain-marie. Once the mixtures have reached the temperature, mix them together.
The Tricoil is now ready to be applied on clean, sanded wood. Apply to the wood once per day for 3-4 days and dry in an open space. 

Burning Station

Since discovering the wonders of Yakisugi, it has become a firm favourite as a method of protecting wood in many of our projects. Our first article in wood protection dives into the science of the method and the properties of charred wood. 

After a fair few projects using our brick burning station at CC HQ, we enlisted it for charring wood for the cladding of the Esposende house. Around a half ton of bricks were put in the van and rebuilt on the street. After so many uses at such high temperatures the normal bricks and even special fire-bricks began to crack and posed a risk of collapse while using the stove. Thus we decided to design a new, super-portable, efficient charring station. 

Blueprint of the new charring station

The body of the charring station consists of an old oil drum, an inlet for passing the wood to be treated through, a feeder for fuel, and a hole to attach a chimney. It mimics the previous charring station with the L shape encouraging an upward draft. The feeder is made of an old fire extinguisher welded on with extra metal for support. 

With the use of two rollers, 1 person can manage the charring station themselves. If the fire is burning well and frequently stocked, it is possible to char a 3m 30x3cm board in 10-15 minutes for both sides. 

The efficiency and speed of this burning station allowed us to burn all the wood for the board and batten cladding of the house in Esposende. Furthermore, this higher degree of flame control allowed us to achieve a uniform result for the boards to not warp and lose their integrity. 

For improvements of the burning station we would advise a metal plate on the lip of the openings for the board to rest on – otherwise it can mark the board. Additionally, a way to adjust the opening for different sizes of boards would increase the efficiency by reducing excess draft. 

Top Tips

Have an ample supply of fuel available to keep the fire well stocked and at a medium-high flame.If the flame is burning too high it is better to do a few quick passes to avoid over-charring the wood which can result in warping.Apply raw linseed oil after charring to compensate for loss of moisture and flexibility.If the wood does warp and you are using it for board and batten cladding, mount the board with the bend curving away from the wall to reduce pressure and prevent cracking. 

There are a few drawbacks of this method and these should be considered before employing this technique in your own projects. One is the time intensive nature of the process. The burning station was fired up most days of the 6 weeks of Esposende workshop. This works if there are many hands available to take on the relatively low-skill task and take turns amongst each other. However it may prove tiresome for a self-build project. The second drawback is the issue of smoke. At Critical Concrete HQ we have neighbours in close proximity, requiring us to build an extra tall chimney to prevent smoking out the neighbours. Having ample space is also a factor to consider. The actual working site of Esposende was relatively small, however, we were lucky to be able to use the quiet street, much to the amusement of the neighbours! Looking to our next renovation project we will need to contain construction activities as much as possible as the street is very narrow with no pavement. For situations when these drawbacks are apparent we endeavour to find more suitable solutions. 

New burning station

Yakisugi cladding on wooden substructure treated with TRICOIL

Swedish Paint / Flour Paint

Filling the requirements of cheap, scalable, non-toxic and accessible ingredients, Swedish Paint is an excellent choice. Swedish paint has long been used as the primary choice for wood protection in many Nordic countries. It can endure the harsh climate while offering an appealing aesthetic. 

Swedish Paint can last for up to a decade before a new application is needed.
Photo by Anders Nord

Method

This is a new method for us and we have tried out one recipe using the materials we had available in the workshop [2].

For 3 litres of paint the following measurements can be used:

300g of flour3l of water600g of pigment300ml of linseed oil

For pigment, we used red clay that we had left over from making a rammed earth floor and wood ash from a local saw mill. There are many options for pigment, do some research and see what is available in your local area. 

This is the very beginning of our research with Swedish paint so there will be more information to come in the future as we experiment with different recipes and ingredients. We will leave these samples outside to see how they withstand the weather.

Paint samples using wood ash and clay

References

[1] ​​https://www.artamin.it/impregnante-ad-olio-fatto-in-casa/

[2] https://engelleben-free-fr.translate.goog/index.php/recette-de-la-peinture-a-la-farine-protection-des-bois-exterieurs?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=ajax,elem&_x_tr_sch=http

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Lately, there’s been an increase in interest over the well-being of coral reefs. These marine habitats represent an estimated $2.7 trillion in ecosystem service value and support around 25% of all marine life after all. But we have already lost 50% of the world’s reefs at this point. And there appears to have been no specific global funding to help develop the protection and restoration of these reefs in the past.

Recognizing this, a coalition of partners from the 75th session of the United Nations General Assembly created the Global Fund for Coral Reefs. With this fund, they hope to raise and invest $500 million (USD) to support programs that will increase the resilience of coral reefs.

That means you may soon see more construction requests for artificial reefs. These sorts of reefs are manufactured constructs designed to promote the growth of coral reefs and provide marine life with shelter. It’s a great way to secure a profitable tender and give back to the environment all at the same time.

But if you do decide to take on an artificial reef project, what can you expect?

You May See a Wide Variety of Structural Requests

Over the years, the innovation for building artificial reefs has only increased. People from all over the world have their own ideas on how to build reefs effectively. So when you do encounter such a project, you might find some unique structural requests. Here are just some of the more well-known ones you might end up with.

They May Be Complex Like a Habitat Skirt

If you win a bid for an artificial reef construction project from a governmental authority, your work may be fairly large and complex.

For instance, back in 2008, the Vancouver Convention Centre used governmental funds to include a habitat skirt worth $8.3 million. The first of its kind at the time, this project used 362 precast concrete slats. They were fit into 76 frames and arranged to look like a large five-tiered staircase. That extended the center’s shoreline by 477 m (1,564.96 ft) and added 6,122 m2 (65,896.66 ft2) of marine habitat surface area.

That is no easy feat for a project that had never been done before! As one of the University of British Columbia’s blogs notes, this amount of space is equivalent to “the length of five Canadian football fields and the floor space of the entire White House.”

It’s also not the only government project thinking big. Further south, down in the United States of America (USA), in San Diego, the port there has started to install a sea wall. Designed to protect the edges of Harbor Island, the wall is expected to help restore the island’s marine ecosystem.

It makes use of a structure that consists of the Coastalock system, which interlocks hollow concrete units to create habitats for oysters, sea stars, algae, and a variety of other marine wildlife.

The port hopes to use 72 of the 3.5-tonne modules of this system to replace the island’s current riprap.

With those two projects in mind, you can see that certain artificial reef projects will involve a decent amount of construction material, some intricate design input, and a keen contractor eye to keep everything working smoothly.

Or They May Be a Smaller Affair Using Reef Balls or Cubes

Not every artificial reef project is so extensive of course. There are plenty around the world that go to organizations like the Reef Ball Foundation and ARC Marine to install concrete structures in waters. These structures may be circular or more cube-like in shape, and they can range in size. Some may be as small as 0.3 m (1 ft) or so or as big as 1.5 m (5 ft) or more. In either case, the structures come with holes and various surface textures to offer marine wildlife places to rest and hide from predators that still look and feel like natural reefs.

They aren’t always interlocked and don’t need any additional design work. So it’s easier for people to order these structures from the organizations making them or from contractors for these organizations and have either group deploy the structures into the water.

It also makes it a less complex project on your end if you win a contracting tender for an organization that already handles this sort of work.

It May Even Involve Just Deploying Materials in a Specific Part of a Marine Area

Sometimes building artificial reefs is all about the materials and nothing else. In some cases, that might mean placing materials like defunct ships, oil rigs, or some other old, large structure into open waters.

In other cases, it might mean doing the same but with defunct subway cars! Running with that last idea, the State of Delaware in the USA has been pushing old New York City Redbird subway train cars into the open waters off the coast of Slaughter Beach since 1996. However, to make sure these cars are marine-friendly, they strip them of any glass, seats, signs, wheels, and petroleum products before dumping them. That way, water can flow in and out of the old vehicles, allowing larvae from sea invertebrates to safely drift in and gain shelter, which in turn, lets them flourish and feed other marine animals.

An even simpler version of this project that you might encounter could be a request to place concrete pipes or steel beams on the ocean floor. For instance, further south from Delaware, in Pinellas County, Florida, such projects have helped to create around 42 reefs.

These Requests Can’t Just Be Fulfilled with Any Material, However

While some projects will already have a specific material in mind like those using the reef balls or reef cubes, there will be others with more leeway. And when that happens, you’ll need to carefully consider what material you use.

Think of it as building a home of sorts. You wouldn’t just use or reuse any old material for a person’s home. It could end up being structurally unsound or even toxic for the person who chooses to live there.

The same can be said for building artificial reefs. If you choose to build reefs by reusing waste like old tires or polyvinyl chloride, you’ll soon discover that neither material is the right kind for marine wildlife to call home. They’re usually too small, for one. So organisms needed to create reefs can’t grow on them. And they’re also very unstable. The waves can carry them to any part of the ocean floor easily, which is not appealing to marine wildlife as reefs are meant to be naturally anchored to the seabed. What’s worse though is that they can both release toxic chemicals, transforming their potential to be homes into a danger zone for any aquatic creature nearby.

So, what can you use instead?

Concrete Is Often the Preferred Material for Building Artificial Reefs

You might have guessed it already considering how often previous projects have used it already. But concrete really is one of the more preferred materials for building artificial reefs. And there are a number of reasons why that’s the case.

According to the New Heaven Reef Conservation Program, some of those reasons have everything to do with the composition and versatility of concrete.

Much like reefs, the composition of concrete makes use of the chemical compound calcium carbonate. Reefs get it naturally through coralline red algae, which form a calcareous skeleton that supports coral reefs by cementing them together. Meanwhile, concrete often gets the compound through common building materials like limestone. But regardless of how they get the compound, that makes concrete at least seem more natural to marine wildlife.

That’s not all that gives its composition such an appeal. Concrete is also innately strong and heavy enough to remain anchored at the bottom of any waters it’s placed in and lasts for a long time, giving marine wildlife a secure shelter for protection or habitation.

But what about concrete versatility?

Well, because concrete can be constructed into almost any shape and size, it gives you an opportunity to give an artificial reef any number of nooks and crannies that fishes and other aquatic wildlife like to hide in.

However, There Are a Few Other Materials You Could Work With

With that said, concrete isn’t the only material that people have gone for when building artificial reefs. They have also gone with the following materials using unique methods:

Electrified steelUsing biorock technology, ecologists in Indonesia have been able to form artificial reefs with electrically charged steel structures. Using a low-voltage current to charge the steel, the ecologists create an interaction between the electricity and the minerals in the seawater. That reaction causes limestone to grow on the charged steel. That growth eventually solidifies, forming reefs much quicker than they naturally would otherwise. This method has also shown to heal injured coral up to 20 times faster than other methods.

Steel spiders Even without electricity, steel remains a good material for building artificial reefs. For instance, people off the coast of an Indonesian island have been attaching parts of coral reefs to rust-protected reinforcing steel structures known as steel spiders. Over time, this process increased the amount of coral on the steel spiders by over 60%. At least 42 different coral species were growing on the steel spiders because of this. And in the rubble surrounding the steel spiders, people found at least 58 species.

Glass bottles in concrete While this method still uses concrete, the main focus is the glass bottles embedded in the concrete. As the concrete keeps the glass bottles anchored securely, the bottles themselves act as a way to transplant broken or nursery corals to attract marine life to the area and eventually create a reef and feeding hub for fish.

If You Do Go with Concrete, Consider Increasing Its Durability

Con-Fume One major artificial reef organization in the USA, the Reef Ball Foundation, requires silica fume in the specs for their artificial reefs. So if you want to follow their design as a blueprint for your own artificial reef, you may want to apply our Con-Fume solution. It is a silica fume product made from pozzolanic material to produce high-performance concrete. It comes in ready-mix bags and meets ASTM and CSA standards for silica fume.

Hard-Cem If you happen to be placing your artificial reef project in waters with swift currents, you may want to add Hard-Cem to your concrete mix. With fast-flowing water, there’s a higher chance for debris to bump up against your reef structure, gradually eroding away its surface and even potentially causing cracks. That surface will likely weaken after some time, leaving it vulnerable to losing aggregate and cement binders to the fast-moving water. But with Hard-Cem, this possibility becomes less likely. As an integral hardener, Hard-Cem increases the abrasion and erosion resistance of concrete and doubles concrete wear life even under harsh conditions. So it is capable of giving your artificial reef the durability it needs to withstand the abrasive and erosive forces in the water.

Krystol Internal Membrane

(KIM Another issue that can threaten your artificial reef’s longevity is a sulfate attack. Sometimes caused by industrial water pollution or seawater, a sulfate attack can chemically change the reef’s cement, weakening its bond with the surrounding aggregate. That can then cause extensive cracking and wear, ruining the structural integrity of your reef. Luckily, KIM can safeguard your reef from such a situation. Using Krystol technology, it enables your concrete to react chemically to water, forming needle-shaped crystals that fill up its capillaries and micro-cracks. That ensures the sulfate in the water cannot get through your concrete and damage its structure. KIM was also one of the top-performing products at preventing the corrosion of steel reinforcement during a 10-year study in a marine environment by the University of Hawaii. Moreover, KIM is also NSF-certified as safe for potable water and has the Singapore Green Label, proving that it is non-toxic.

You’ll Soon Have an Artificial Reef Perfect for Clients and Marine Life

Knowing what to expect and what tools to consider now, you’ll be ready to create a marine-friendly artificial reef of your own in the future. Just keep in mind the potential scope, materials, and obstacles you might encounter, and you’ll have an artificial reef up in no time.

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