A strawboard panel is a rigid building panel made of a solid core of compressed wheat (or rice) straw covered with recycled paper liners which are stuck to both sides with non-toxic, water-based glue. A standard strawboard panel measures 4 feet by 8 feet by 2¼ inches thick and weighs 120 poundw; custom sizes are also available, from 1 to 3 inches thick and from 3 to 12 feet long. Strawboard panels make an excellent alternative to timber for frame structures, interior partition walls, floors, load and non-bearing ceilings, roofs, and prefabricated buildings.
Most importantly, in these environmentally-conscious days, strawboard comes from an economical and recyclable source: the straw that is left over as a byproduct of harvesting wheat grain. In the U.S. alone, 60 million acres of wheat are grown each year resulting in 140 million tons of straw that is mostly disposed of by open air burning. This not only adds to global warming but can also create severe seasonal air quality problems have across the country. If the building industry comes to embrace strawboards panel on a large scale, this problem will go away. According to one estimate it takes about 18 acres of wheat straw (replaceable every year) to build a 1,760 square feet house. It takes the equivalent of one acre of clear cut forest (replaceable every 30 years) to build the same house.
In the manufacturing process, high pressure and temperatures up to 240°C forces the straw to release a natural resin, which binds the fibers together. The high density and low oxygen content of the resulting panels makes them resistant to combustion and, since they contain no added resins, alcohol, or other chemicals, they don't release flammable vapors. A standard 2¼-inch panel has a one-hour fire rating, an R-value of 3, and noise level reductions from one side to the other of 32 dB. For permanent protection against insects and fungal decay and additional fire resistance, the boron compound polybor can be factory added to the core. The product's workability is similar to wood as it can be sawn, drilled, routed, nailed, screwed, and glued. Lightweight wall attachments such as shelf brackets, picture frames, mirrors, and towel bars can be attached directly to the panel. Up to 35.2 pounds of direct pull load and 79.2 pounds of shear pull load can be achieved using screws.