This standard specifies the testing method to determine the surface spread of flame characteristics of fire-retardant treated timber. It provides a classification system based on the distance and rate at which flames travel across the wood surface when exposed to a radiant heat source.
Specifies the procedure for conducting a crib test to determine the fire retardant properties of treated timber specimens.
Quick Reference Values
Conditioning temperature27 ± 2°C
Conditioning relative humidity65 ± 5%
Specimen length900 mm
Specimen width230 mm
Test observation duration10 minutes
Key Formulas
Weight loss (%) = [(Initial Weight - Final Weight) / Initial Weight] x 100
Practical Notes
Ensure timber moisture content is properly conditioned (typically to equilibrium at 65% RH) before testing, as moisture significantly affects flame spread.
Do not confuse surface spread of flame with structural fire resistance; this test does not evaluate the load-bearing capacity of the timber under fire conditions.