Finger Lakes Building Officials, Inc.

An Affiliated Member of the New York State Building Officials Conference

POSTED August 2009

Question:

When the ceiling of a garage is used to complete the required fire barrier between the garage and the dwelling, do the walls supporting the ceiling in the
garage also have to be dry walled?

Answer:

Generally, no. But, Section R309.2.2 does require that "... Where the horizontal separation is a floor-ceiling assembly, the structure supporting the
separation shall also be protected by not less than 5/8- inch (15.87 mm) type X gypsum board or equivalent."

Where an attached garage shares a (gypsum board-protected) wall with the dwelling, and there is no floor-ceiling assembly, the other walls may have the
wood framing exposed. Is this a dangerous condition? Probably not as much as you'd think. Given that the typical fire burns upward, the house is properly
separated/protected, and there is no usable space above the garage to be protected, if the exposed wood wall framing burns and eventually fails, the
occupants of the house, if still inside, should still be relatively safe/protected. And remember that statistically*, a fire is much more likely to
occur in the kitchen or where the heat-producing equipment is (typically the basement) and those areas do not have to be sheet rocked.
Your administration and enforcement of the New York State Uniform Fire Prevention and Building Code should be consistent with this application as follows.

DATE: August 27, 2009
TO: Robert Prince, CEO; Town of Parma
FAX: 585 392-6659
FROM: Cheryl A. Fischer, P.E.
Assistant Director for Code Interpretation

NOTE: residential garage horizontal separation

This is in response to your question regarding whether Residential Code of New York State Section R309.2.2 requires the supporting construction for residential garage horizontal separation to be fire-resistance rated. Section 309.2.2, Horizontal separations, states:

Where horizontal construction is used to separate the garage from the living space or its attic, such construction shall be protected with one layer of 5/8-inch thick, type X, gypsum board, installed in accordance with the requirements of Section R805.1. Openings in horizontal separations shall not be permitted except where the residence is otherwise protected by vertical separations. Where the horizontal separation is a floor-ceiling assembly, the structure supporting the separation shall also be protected by not less than 5/8- inch type X gypsum board or equivalent.

The phrase “floor-ceiling assembly” means that there is a floor in the attic of the garage. If there is no floor in the attic of the garage, the space will not be used for storage, there will not be a stair or an opening. In this case the supporting construction (the other three walls of the garage) are not required to be fire-resistance rated.

Submitted by Jim Bailey

Finger Lakes Building Officials Association, Inc.
3100 Atlantic Ave.
Penfield, NY 14526
flboa.info@gmail.com