Fire barrier continuity

[Paul Spencer]

For a fire barrier where it meets an exterior wall, I am looking for a code requirement for a fire barrier to extend to the inside face of exterior sheathing. In my specific case, it's a 2 hour fire barrier meeting an unrated exterior wall. Do the two layers of gyp board on each side of 3 5/8" metal studs have to extend to the inside face of the exterior sheathing, and be fire caulked to it?

 

[RLGA]

There is no requirement to extend a fire barrier to the sheathing of a non-rated exterior wall. The joint (if any) shall comply with Section 715. For gypsum board to gypsum board construction, having taped and finished joints is sufficient.

 

[classicT]

To expand upon Ron's answer, 707.5 requires that fire barriers be framed tight to floor or roof sheathing and that fire resistant joints be used at intersections per 715. Per 715.1 Exception #7, where a fire barrier intersects a wall permitted to have unprotected openings, the fire resistant joints are not required. A non-rated exterior wall would have unprotected openings, hence Ron's correct answer, it is not required to extend to exterior sheathing.

Typically, to justify that the fire barrier provides continuous separation, one needs to either run tight to exterior sheathing OR run to an exterior wall and use an approved joint (i.e. taped and finished GWB joint).

BTW, the detail that you shared is typical of most projects, although it exceeds the code requirements.

 

[cda]

welcome!!!!!

Just a note:

Even though it has the word fire in it, it is still a building code item

 

[cda]

If this is for a proposed project,,

Why is the two hour wall needed??