Garage Firewall

If a firewall is required between the garage and the house, why is it I seldom see one? Did a 3 year old townhouse this week and there was no separation at all. (Behind the studs in the attached photo is the attached garage.)

What exactly should the separation be composed of? Sheetrock? That black wall board? Should the material have any special identification??? If there is any opening at all, that would be a concern right?

I see the firewalls all the time between condo/townhome units, but I hardly ever see it between the house and garage. When did that rule come into being? If the house is a 1973 job, like my mother’s, was the code applicable then? Would you recommend installation of the firewall to an older home?

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The wall separating the garage from the house needs to have 1/2-inch-thick (one hour rating) gypsum board on the garage side using Type X gypsum board, as well as fire tape (in some juridictions) to seal joints on drywall and gypsum board.

If there is any habitable space above the garage, (which in your case-there’s not) 1/2-inch gypsum board is required on the garage ceiling. In addition, all of the supporting walls need to be clad with 1/2-inch gypsum board. Basically, you should see a fire-rated floor-to-ceiling assembly.

When the soffit area of the garage and the house are common, the fire wall shall extend through the soffit.


I don’t care how old the home is, I always recommend a fire barrier between any living area and garage. If the buyers don’t do as I say, and someone dies…I told them so.

Safety of human life doesn’t have a date…

David, I believe one would need 5/8" type X for the one hour rated wall rating.

How 'bout this barrier? The board says “Caution: May smolder or burn if ignited.”

How do I find out if the gypsum board you mentioned is “Type X”? Where is the label when I see it installed on a wall already?

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David, where you mentioned soffit area, that should read attic area…

…that’s what I thought too…but having never heard of the soffit separation before, didn’t comment.


1/2 " or 5/8" … who’s got that tape measure?

Nope, I wrote it correctly…

When the soffit area of the garage and the house are common, the fire wall shall extend through the soffit.

In other words, No gaps should be visible period.

The Gypsum Manufacturers…and the attorneys. :cool:


I’m simply referring to a home inspection. I was off by an eigth of an inch but I’m quite sure the manufacturers won’t be.

5/8 type x fire rated as already mentioned.
Its always stamped on the edge.You just can’t see it once it’s mudded and taped.
However if there is a door between the garage and living space the door jamb will be a bit wider , to accept 1/2" on one side and 5/8" on the garage side,than any other entry jamb in the house if fire rock is present.One also needs to know if the framing is 2 x 4 or 6 to make an accurate assesment.
One may also be able to tell at an outlet or switch minus it’s cover if it isn’t fitted to snuggly to the rock.

okay…my knife is out and I’m lying on the pointy end… go ahead somebody jump on me.:lol:

One more opinion: :slight_smile:

The difference between 1/2" and 5/8" rock? (aside from the fire-rating)
5/8" is alot heavier…well 25% heavier, harder to carry, harder to cut, harder to hang. My opinion from a builder’s perspective, 1/2" rock doesn’t work so well on a stud wall or ceiling that is framed at 2’ O.C. When you feel that the wall-board is wobbly, or when you see that it has sagged from the ceiling at regular 2’ intervals, it could be because it is 1/2" rock instead of 5/8", hung on 2’ centers.


No problem David.

I simply thought by this statement you made…

1/2 " or 5/8" … who’s got that tape measure?

…that you implied it didn’t matter.

Garage attic sheathing separating it from the house framing. 1999 house inspected today.

I’m beginning to think NOBODY does it right.

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this may be nit picky, (but that’s my job), 5/8 sheet rock is only 1/2 at the factory taper (were you usualy mud and tape). would that make the wall under the fire code in the 6" span of every untaped joint were 2 tapers meet???

Nice firewall.

That material is only utilized for insulation purposes and definitely needs gypsum board installed over it.

Dosen’t quite meet the 1-hour separation by code or the IRC does it.!?