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Party wall questions

moose_head27 | Posted in Building Code Questions on

Hi, I was curious to know if the drywall for party walls( 1 hour fire separation) are required to be continuous across interior wall framing?

For example would the interior wall framing for a wall need to be offset to allow for a continuous layer of drywall between party wall and interior wall? Or is it negligible as areas where there is interior framing compared to the area of the wall would be minimal in comparison.?

Thank you

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  1. Zdesign | | #1

    The drywall layer needs to be continuous and any penetrations need to be 1 hour rated as well. If you get into the 2 hour assemblies its a bit different. Make sure to review the UL Assembly requirements also.

  2. Expert Member

    Moose Head,

    I don't know what code you are under, but here the answer is no. The studs at the intersection of the walls, and drywall on the interior walls, provide the equivalent fire rating.

    I'd suggest you talk to your Building inspector to confirm what the requirements are there.

  3. Expert Member
    BILL WICHERS | | #3

    All you need to do to build a fire rated wall is to build one of the listed assemblies. For a 1 hour wall, this is usually one layer of 5/8” type X drywall on both sides of a regular 2x4 studwall (either wood or metal studs). 2 hour walls are two layers. All penetrations (wires, pipes, doors, everything) need to be made using listed materials rated for the same number of hours as the wall. It’s important not to miss the firestopping of any holes in the wall assembly.

    You tape and mud the drywall in the usual. The idea is to make sure smoke, hot air, and flame can’t get through the wall anywhere more easily than going through the drywall panels themselves. The purpose of a fire rated wall is to slow down the spread of fire (that’s what the “hour rating” part is about), usually to give people time to get out of a burning structure.


  4. Expert Member
    Peter Yost | | #4

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