Cement Board Siding Fire Rating

Icc es ner 405 fire resistance rated wall assemblies ner report ner 405 click the link above and go to section 3 5 of ner 405.

Cement board siding fire rating.

Two hour fire rated construction chase walls steel framed acoustical performance construction detail description test number stc test number 9 1 2 usg durock brand cement board and 1 4 ceramic tile two rows 2 x 4 wood studs 16 o c. Many fiber cement products carry a class a fire rating meaning that they can withstand several hours of heat before melting down. Yes hardiebacker 1 4 cement board is deemed noncombustible when tested to astm e 136 and can be used in conjunction with other noncombustible materials around a fireplace. On 2 x 8 common plate 3 1 2 thermafiber safb both cavities joints taped.

Unlike wood it is fire resistant. It can be used as part of a hour long fire wall which is a wall that can resist a fire for up to an hour. The exact fire rating of durock is dependent on the other materials used during construction but a panel 1 4 or 1 2 inch thick typically provides an additional hour of fire protection. Nichiha s robust architectural wall panel rainscreen system and thick sierra lap board are ibc code compliant for use as exterior cladding in fire resistance rated wall assemblies.

This does not mean that clearances to combustible building materials can. Fiber cement siding maintenance. Hz5 climate zones 1 5. This means that coupled with other fire resistant building materials including insulation and framing fiber cement siding will withstand fire and in some cases even increase the assembly s overall fire resistance.

A durock panel with a thickness of 1 2 or 5 8 inch can provide two hours of fire protection when installed correctly and in conjunction with all fireproofing. It offers the look of authentic wood shiplap siding even with lookalike textured wood grain. Here are the main installation considerations with respect to the choice of materials. Fiber cement siding stormed onto the scene a few decades ago and revolutionized the house siding industry because it possesses the best of many worlds.

However using fiber cement board like hardieboard is acceptable in locations including the mantel and fireplace surround. James hardie uses what it calls the hardiezone system. Fire ratings the hardiebacker board is made with a quarter inch thickness so that it can serve as fireplace facing. Hardietrim boards hardiesoffit pre cut panels artisan by james hardie hardiewrap weather barrier hardiebacker cement board.

The predominance of wood in the mix makes smartside siding more susceptible to fire though it does have a 1 hour fire rating.