Open Biotecture worked in collaboration with Abari to research and develop ways of using bamboo shingles for building sustainable homes.
Why using bamboo? Bamboo is a fast growing grass, it is light weight and strong. It is also relatively easy to cut and shape into shingles.
Bamboo shingles are used in South East Asia, where bamboo grows abundantly. Other kinds of wooden shingles also are found all over the world.
The potential problem of bamboo shingles would be durability. Abari has developed a means to treat bamboo chemically so it is more resistant to pest. However, exposed to the monsoon rains and scorching sun of Nepal, how long would bamboo shingles last?
Open Biotecture has looked into ways of coating bamboo shingles with natural products. For this we have used a natural resin produced by the sal tree, commonly referred to as “saalko dhoop” (सालको धूप, sālko dhūp), which is used as an incense. This resin is very much like myrrh or frankincense. To use this resin, we dilute it with turpentine, which itself is derived from resin as a product of its distillation. Turned from a solid to a liquid state, the resin can be applied to the bamboo or other surface. The resin dries rapidly and several layers can be applied.
We have created few small tests of bamboo shingles, focusing on the shingles more than on how they would be installed onto a roof (which we didn’t consider to be a difficult thing to do). We have worked on three models of shingles, a curved fish-head design, a flat fish-tail design and a flat double layered shingle panel. We have applied resin on these as well as other coatings, such as shellac and black japan, in order to compare results. In our experiments, we have tried using oils, butters and wax, but the results were not convincing.
We feel quite confident that the resin will help increasing the durability of the shingles significantly. How long those will last exactly will be only revealed through time. Building shingles in a way they can be easily maintained in the future will only add to the efficiency of this type of roofing.