Cement Board Siding Fire Rating

Fiber cement siding maintenance.

Cement board siding fire rating.

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. Options like cement board siding come in a variety of modern textures profiles sheens and shapes providing an abundance of design flexibility while still being fire rated. Fire ratings are assigned to assemblies not components. Unlike wood it is fire resistant.

Are your products 1 hour fire rated. Additionally they slow fires from spreading into buildings and damaging property so that s more time for the fire department to reach your home in case of an emergency. However using fiber cement board like hardieboard is acceptable in locations including the mantel and fireplace surround. This does not mean that clearances to combustible building materials can.

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. Occasionally an inspector will allow a substitute but not often. It offers the look of authentic wood shiplap siding even with lookalike textured wood grain. How they get the rating is to build a wall or ceiling or whatever and subject it to a standard fire.

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 construction materials. Hardietrim boards hardiesoffit pre cut panels artisan by james hardie hardiewrap weather barrier hardiebacker cement board. 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. It s available in a variety of sizes and shapes to match many of the old siding shingles installed over the last 60 years.

Many fiber cement products carry a class a fire rating meaning that they can withstand several hours of heat before melting down. 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. 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. If you change any part of the assembly technically even using different fasteners is a change then the rating is not valid.

On 2 x 8 common plate 3 1 2 thermafiber safb both cavities joints taped. Fiber cement siding maintenance. Fire ratings the hardiebacker board is made with a quarter inch thickness so that it can serve as fireplace facing.