Our Wall System
The basis of the Biostruct Earthen Wall Systems is a hemp-flax-lime-clay mixture that hardens with properties that resemble masonry. It is used in construction to create breathable, monolithic wall systems.
In construction, the Wall Core material is packed into a formwork, or shutter system that is temporarily attached to a light wood frame. The shutters can be removed shortly after the material is packed. Once dry, the Wall Core is coated with plasters that protect the insulating core.
Japan Hemp House
Hemp has been used in building throughout the world for many years. A sixth century petrified hemp-reinforced bridge in France is still in use today – showcasing the stone-like strength and durability of this material. Similarly built houses over 300 years old can be found in use in Europe and Japan.
THE VALUE OF OUR WALL SYSTEM
There is much to be learned from buildings that have lasted centuries! Biostruct’s thick walls have the thermal mass of old-style masonry, providing for steady indoor temperatures. The hemp fibre in the masonry adds insulation to the wall. When built properly, the wall should have no thermal bridging which would lead to condensation problems as well as temperature loss.
Hemp is a fast-growing and versatile crop. The plants sequester large amounts of carbon dioxide (10 tons per acre), reducing the atmospheric pollution that contributes to climate change. While most plant straw yields about 1.3 tons of fibre per acre, hemp weighs in at 4.5 to 7 tons!
The Biostruct Wall System is used with a supporting frame of another material to carry the vertical load during building construction. Once it has set, Biostruct’s density is 15% that of traditional concrete.
MORE GOOD REASONS TO USE BIOSTRUCT HEMP MASONRY
Fire-resistant and Insect-resistant
Non-brittle – lacks the brittleness of cement and consequently does not need expansion joints
Insulating – Values equal or surpass conventional products (R-value of 3.0 per inch)
Hygroscopic – (Vapor permeable) Absorbs and handles moisture. Just as our bodies need to “breathe” by releasing moisture and toxins through our skin, our homes – and more particularly, the walls of our homes – should also “breathe.
Biostruct’s solid mass construction eliminates air gaps, but remains breathable. This breathability prevents the buildup of mold and mildew. However, most homes built today are completely sealed with vapor barriers in order to prevent moisture transfer. Water has a way of getting inside those seals – for example, by condensation through cooking, doing laundry, showering or structural leaks. This humidity doesn’t just go away! Once moisture enters a sealed wall, it has nowhere to go and the result is mold, decay and rot.
Natural cements have also been called “living cements”, meaning they bind well with plant cellulose. Examples include high calcium lime and magnesium cements. Portland cement, on the other hand, actually repels cellulose, and must therefore be combined with plastic binders to permit adherence to building substrates. These petroleum-based binders make the concrete more hydrophilic, locking in moisture and thereby increase the risk of mold and mildew formation. Natural lime’s curing cycle also makes it more attractive over concrete to use in this case, as it reverts back to limestone partially by sequestering CO2 from the air. This renders buildings to virtually carbon-neutral. Whereas, Portland cement is produced using a much more energy intensive burning process than that of lime, and without the benefit of re-absorbing the CO2 it has released.