A Straw and Rice-Husk Fibre Insulation Panel: Specification and Computed Thermal, Moisture, Cost and Fire-Behaviour Envelope

A specification and computation study (SIMULATED, NOT MEASURED; no panel built or hardware-tested) of a non-loadbearing insulation panel of 68% straw fibre, 22% ground rice husk, 6% starch binder and 4% borate treatment at 110 kg/m3. Dry conductivity 0.049 W/m.K gives 0.51 m2.K/W per 25 mm; a 100 mm panel gives 2.041 m2.K/W dry and 1.624 at 80% relative humidity, at a computed US$8.42 per square metre. Design moisture limit is 16% by dry mass (84.7% RH in the model); liquid wetting is excluded. Fire statements are computed bounds only, not certifications: the panel is combustible, carries 184.8 MJ/m2 at 100 mm, and computed ignition above the assumed critical flux takes of the order of one second, so it may be used only as protected infill behind a non-combustible lining in code-permitted, assembly-tested constructions, and never exposed, in escape routes, or as unprotected external-wall insulation. Includes computation script and saved outputs.