Cement Board Siding Fire Rating
It s available in a variety of sizes and shapes to match many of the old siding shingles installed over the last 60 years.
Cement board siding fire rating. 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. 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. 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. Fire ratings the hardiebacker board is made with a quarter inch thickness so that it can serve as fireplace facing.
However using fiber cement board like hardieboard is acceptable in locations including the mantel and fireplace surround. Hardietrim boards hardiesoffit pre cut panels artisan by james hardie hardiewrap weather barrier hardiebacker cement board. It offers the look of authentic wood shiplap siding even with lookalike textured wood grain. 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.
Fiber cement siding panels can improve the overall fire resistance hardening rating of your home which is helpful for insurance purposes in western locations like california. 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. Unlike wood it is fire resistant. Many fiber cement products carry a class a fire rating meaning that they can withstand several hours of heat before melting down.
If you change any part of the assembly technically even using different fasteners is a change then the rating is not valid. 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. Fiber cement siding maintenance. 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.
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. Fire ratings are assigned to assemblies not components. How they get the rating is to build a wall or ceiling or whatever and subject it to a standard fire. Weatherside fiber cement siding is the 1 and weatherside fiber cement siding is the 1 and only solution for replacing or repairing old asbestos siding shingles.
Are your products 1 hour fire rated. Occasionally an inspector will allow a substitute but not often. This does not mean that clearances to combustible building materials can.