Background: We have a full basement and I have recently completed about half of it as a hang out spot for my teenage boys and their friends. The other side I use as a workshop and a place to store "stuff". The ceilings are about 9 feet high in the unfinished side and 8 feet high on the finished side. The unfinished side only has exposed floor joists, wiring, etc. The finished side has a suspended ceiling. The wall between us is finished on their side with 1/2" drywall. My side is bare studs. Also, the basement stairs are between us - finished on their side, unfinished on mine.

My Question: I want to finish my side of the wall and would prefer to use wood rather than sheetrock. But since my side has the furnace, do I have to install fire-rated drywall between us? I won't be able to completely close off one side from the other because the wall is perpendicular to the joists above, so even if I run drywall to the top of my wall, there's still about 10" of clearance between the joists. It seems that fire-rated drywall would not be necessary since any fire would just burn above the wall and into the other room.

3 Answers 3


This will likely be a location specific issue, so it doesn't hurt to check your local codes.

All the fire rated work that I've done has been between units (both to other units and common areas) and any load bearing structures of a multi-unit dwelling. When we do that, fire blocking is installed in the ceiling space as well to prevent a fire from traveling through the ceiling to another unit. For everything else within a single unit, and in a single family home, we don't use any fire rated drywall.

Edit: A few reasons I'd disagree with Eric on this one. First, I'm presuming you already have a certificate of occupancy (or someone did) to move in with an unfinished utility room. That required an inspection that presumably allowed the space as is. Next, most codes for combustion devices (furnace, gas hot water) require that you have ventilation. Installing a vented door is perfectly acceptable and won't provide any fire stopping. And, finally, most HVAC's (if the furnace is forced air) will be connected to vents that run to every room in the house. From the little I saw, the furnaces and utility rooms in searches likely referred to multi-unit dwellings, and that does need to be fire stopped. You also have to use fire caulk around every hole. Our multi-unit buildings also have sprinklers throughout and spring loaded vents that snap closed in event of a fire.

That all being said, there's absolutely nothing bad about installing fire rated material around the furnace, other than the extra cost and that it's a bit more difficult to cut. If you want to do it, then by all means, do so.

Edit 2: One last note, realize that fire rated drywall increases the resistance from 30 minutes that you'd typically see with 1/2" drywall to 1 hour. Fire rated doesn't mean fire proof.


There is absolutely no codes, IRC or otherwise that require fire rated materials between a standard domestic furnace space and other living spaces as you describe. Do the walls with whatever you want, you have no problems with that.

  • don't confuse the terms "utility room" with "mechanical room". They are not the same, it maybe semantics, but accurate. I can never figure some local codes, won't even try anymore, but there is no IRC or NEC codes for fire rating furnace space in a single family residential home. Period. Commented Jun 15, 2011 at 8:52

This is going to depend on your local codes. I know around here (Grand Rapids, MI) fire rated drywall and fire blocking is required for a utility room containing a furnace.

I'm surprised others are saying that it isn't required in their area. A google search finds me several sites that mention using fire rated drywall in utility rooms, which leads me to believe that is a relatively common code requirement.

  • Yeah, that's kind of what I found as well. But because I don't have a finished ceiling and can't really (without a LOT of work) completely close off the area, I'm thinking the fire rated drywall isn't going to offer a great deal of protection anyway. For example, the floor joists above will burn with or without the fire rated drywall.
    – bkcarroll
    Commented Jun 14, 2011 at 23:33

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