Hempcrete Fire Performance — References & Testing

ASTM E84 Surface Burning

Independent ASTM E84 tests on hemp-lime walls have reported Class A flame spread and smoke development ratings. Class A is the highest non-combustible interior finish classification recognized by U.S. building codes.

4-Hour Fire Rating Context

Multi-hour fire endurance results for hemp-lime walls have been documented in European testing under EN 13501-1 and equivalents. Listed assemblies vary by thickness, density, and finish. Specify by tested assembly for code submittals.

What this means in practice

Hempcrete and GaiaCrete® do not require added chemical flame retardants. No off-gassing of halogenated fire chemistry. Specifications and stamped engineering for your project are available on consultation.

• International Hemp Building Association — fire research summary
• ASTM E84 standard test method