Townhouse Fire Wall

[rosegamble]

Hello! The residential code says the fire-rated demising wall between townhouses must be "tight against the exterior wall." If it was framed out of wood 2xs, are we talking about tight against the exterior face of the exterior wall (sheathing) or tight against the inside face of the interior wall? It does specify ending at the sheathing for vertical cancellation of the demising wall (at the roof) but is not so specific when it comes to the wall/exterior wall intersection.

 

[mtlogcabin]

We make them take it to the exterior sheathing

 

[steveray]

With the IRC wording the way it is and not using the term "firewall"....it should be the interior face of the wall.....IBC firewalls typically go out to the sheathing....(that I see)

 

[redeyedfly]

I typically see this interpreted as to the inside face of the sheathing, roof and wall.

 

[classicT]

Agree with others here, the gypsum needs to run tight to the inside face of the exterior sheathing or exterior cladding where not sheathed.

 

[mtlogcabin]

R302.2.3 Continuity.
The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

 

[Genduct]

Hello! The residential code says the fire-rated demising wall between townhouses must be "tight against the exterior wall." If it was framed out of wood 2xs, are we talking about tight against the exterior face of the exterior wall (sheathing) or tight against the inside face of the interior wall? It does specify ending at the sheathing for vertical cancellation of the demising wall (at the roof) but is not so specific when it comes to the wall/exterior wall intersection.

Your question is does gyp need to be next to wall sheathing or just the studs

As you are bulding the first unit you can and should sheath the wall for shear wall strength, then install the 2 layer fire wall of gyp But then you install the stud because you probably would not want to erect short wall segments with sheathing securely fastened. The drywall will give it the shear strength

You should check to see if the design Professional agrees with the Wind Bracingstrength of this suggestion.

 

[rosegamble]

Thanks, everyone! From a moisture perspective... it seems odd to run the gypsum right to the inside face of exterior sheathing... no?

 

[Genduct]

Thanks, everyone! From a moisture perspective... it seems odd to run the gypsum right to the inside face of exterior sheathing... no?

I thought we werespeaking about the shared FIRE WALL that is NOT and exterior Wall
The question is How to build the structural Stud walls with the Non Structural GYP Fire Wall