by Jerry Peck - Codeman on Sat Oct 10, 2009 5:40 pm
Hi Bruce,
Fireblocking is required for all occupancies where there are concealed spaces, such as for the stud walls in the garage you are describing.
The key to that requirement is "concealed" spaces, such as the stud cavities enclosed and concealed between the studs and the drywall and drywall (or drywall/exterior sheathing, or any wall surface enclosing the stud cavities and the surface on the other side of the studs which makes that space enclosed).
Those concealed spaces would be required to be fireblocked at the garage floor (which they already likely are) and at the top of the studs where the top plate is.
Fireblocking is not the same as fire caulking, however, whenever fireblocking is penetrated the space around the penetration much be sealed with a suitable material, and fire caulking will work for that in most cases until you get into actual fire-resistance rated assemblies, then the penetration must use a firestopping listed penetration, not just "fire caulking" per se.
In an unrated assembly, such as that garage wall, the top plate serves as the fireblocking. Any and all penetrations through the top plate then must be sealed around. The IRC states it this way: "At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion." - i.e., "fire caulking", which is an intumescent material.
Jerry Peck - CodeMan
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Construction Litigation Consultant - Retired
Construction and Code Consultant - Semi Retired