Fire Treated Wood in Walls

Q: I have a contractor coming in to put up a wall in our nursing home dining room. He is wanting to use fire treated wood. Would this be acceptable to the Life Safety Code?

A: Did you first discuss this with your architect? Or did you first discuss this with your state agency that licenses nursing homes? You need to do that to make sure what you install is compliant with codes and standards.

I cannot answer your question because I do not know what your construction type is, how many stories you have, and whether or not you are fully protected with sprinklers. Is this wall going to be load bearing or non-load bearing?

If your facility is Type I or Type II construction, then combustible materials are not permitted on load-bearing walls, and other structural members. Fire-treated wood is considered combustible, so it would not be permitted for use on structural members of the building.

According to section of the 2012 Life Safety Code, it says interior nonbearing walls required to have a minimum 2-hour fire resistance rating shall be permitted to be of fire retardant treated wood enclosed within noncombustible or limited-combustible materials, provided that such walls are not used as shaft enclosures. Is the wall going to be fire-rated to a minimum of 2-hour rating? But this section does not permit fire-retardant wood to be used on walls that are less than 2-hour fire rated.

According to section, fire-treated wood that serves as supports for the installation of fixtures and equipment shall be permitted to be installed behind noncombustible or limited combustible sheathing. You definitely need the gypsum board sheathing to cover all of the fire-retardant-treated wood, but that’s only for fixtures and equipment supports.

The way I read the LSC, unless the fire-treated wall is a 2-hour fire-rated wall, or the fire-treated wood is used to support equipment or fixtures, then it is not permitted in a healthcare occupancy.

Before you let this contractor begin, you really need to contact your architect and have him/her design the proper wall assembly, and then have it approved by your state and/or local authorities.