Build a fireproof house with hemp blocks

The California fires are devastating and undoubtedly families will want to rebuild what was lost. There's a lot of talk about it on social media platforms, such as investor Bill Ackman, who wants to invest in AI technologies to predict drones and help stop fires. But sometimes traditional building and sensible ecological practices can save from technology in an area called low-tech.

Fire hydrants and water-filled drones could put out a fire if discovered in time, but protecting your future from disaster could be a sensible and sustainable step. Hemp blocks, also known as hempcrete, are already on the market and are environmentally friendly and sustainable building materials made from hemp, lime and water.

In a recent study, scientists are examining the fire behavior and structural performance of hemp-based materials in various formats. They tested raw hemp shives, hemp blocks, and non-load-bearing hemp block walls.

Researchers tested how different types of hemp reacted in fire protection and strength tests.

The study found that hemp blocks do not catch fire when exposed to an open flame, but rather smolder slowly, producing very little smoke. In fact, walls made of hemp blocks remained structurally intact for two hours during fire tests.

Tests performed include cone calorimeter, bomb calorimeter, standard oven, heat transfer evaluation system (H-TRIS), and small elevated temperature material testing. Hemp shives exhibit sustained flame ignition, a relatively high heat release rate (HRR), and a relatively low critical heat flux (CHF).

However, the hemp blocks did not show flame ignition, only a smoldering burn and an order of magnitude lower HRR. Hemp blocks and hemp shives produced minimal smoke. Charred hemp blocks and associated discoloration zones were documented. Tests show that up to 200°C a limited structural capacity is lost, whereas at 300°C the residual strength of the material is almost negligible.

Their conclusion was that the hemp block walls maintained their structural stability and integrity through a standard two-hour fire test. The compressive strength of the hemp blocks at ambient temperature was determined to be 1.0 MPa. This work is the first comprehensive study of the fire behavior of hemp blocks and highlights their good performance while likely having limited impact on fire risk in buildings.

Plastered walls have a fire protection effect that goes beyond the values ​​given in the study, the researchers say. The work was reported in the Journal of Building Engineering.

The research was led by Yohannes Werkina Shewalul and Richard Walls of Stellenbosch University, South Africa.

Hemp or industrial hemp is a plant from the botanical class of Cannabis sativa varieties, cultivated specifically for industrial and consumer use. It can be used to produce a wide range of products. Along with bamboo, hemp is one of the fastest growing plants on earth and is a great, hearty and sustainable fiber. It took years for nations to recognize hemp as a viable construction and material alternative because hemp contains tiny amounts of the active ingredient THC.

Companies producing hemp blocks:

Comments

Comments