Post Fire Retardant Treatment
Question:
Is a Class A fire rating (provided by our liquid spray-on fire retardant) acceptable in certain situations?
Answer:
Class A (or I) rating typically indicates a flame-spread rating or index of 0-25 when tested per ASTM E84. It is typically a rating applicable to interior finishes (IBC 2012/2015 803.1.1) but also is applicable to fire-retardant-treated wood (IBC 2012/2015 2303.2), which allows treated wood products to be tested per the listed requirements.
Whether or not the Class A fire rating of a treatment product is sufficient for a specific situation – including a situation in which you’re trying to determine whether a metal plate connected wood truss or any other wood structural material is a building code issue – should be determined by the building designer.