Why James Hardie / Fire Prevention FAQ
Read answers to frequently asked questions.
Are your products 1-hour fire-rated?While JamesHardie® products will not ignite when exposed to direct flame or contribute fuel to a fire, heat will transfer through them. Because of this, the product itself is not 1-hour fire rated. However, they do qualify for use in certain 1-hour fire rated Warnock Hersey and UL assemblies. Think of JH products as a pan used for cooking. The pan can be directly exposed to a stove's flame and not burn, yet the food in the pan will cook in time. Having an interior wallboard that resists burning for 1-hour buys time for the homeowner and fire professionals.
What constitutes a 1-hour fire-rated assembly?The period of time a fire resistant building element like JamesHardie® Siding along with other components of the assembly maintains the ability to confine a fire, continues to perform a given structural function, or both, as determined by ASTM E 119 tests.
Are James Hardie products a masonry product?The Uniform Building Code defines masonry as a form of construction composed of stone, brick, concrete, gypsum, tile, glass block or other materials laid up unit by unit and set in mortar. Although James Hardie products are installed with nails, like most masonry materials, they are primarily cement with performance characteristics similar to brick, stucco and stone. These characteristics include fire, moisture and insect resistance. Many cities include fiber-cement in their masonry definitions for these very reasons.
What is fire resistance?The property of a wall assembly used in conjunction with JamesHardie Fiber Cement that prevents or retards the passage of excessive heat, hot gases or flames under conditions of use.
Can James Hardie products be used around a masonry fireplace?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. This does not mean that clearances to combustible building materials can be reduced by using HardieBacker 1/4". Clearances to combustible building materials shall be obeyed even if they are protected by noncombustible materials, please refer to your local building and fire code for specific combustible clearance details around masonry fireplaces.
Can you substitute JH products for gypsum to achieve a 1-hour rating?Because heat will transfer through JH products, they cannot be substituted for Type X, fire-rated gypsum.
Can I receive a discount on home insurance for using JH products?Because JH products are non-combustible, many insurance companies offer a discount. We recommend sharing the information on this page with your insurance company if they are not familiar with fiber-cement siding's fire-resistance.