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Community and Q&A

Basement wall: Do I use single or double top plate?

PLIERS | Posted in General Questions on

I’m confused on when and why I would use a double top plate.  I’m building basement walls by myself.  Also if a wall is very long how do I build in sections and connect walls for best results.   I was thinking stick building would be easier.  I have about 30 foot wall and am working by myself.  Is there a way to build in 8 foot sections and not compromise wall strength.


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  1. Expert Member


    The benefits of double plates are that they carry loads to the studs if they aren't directly over them, and by lapping it ties the walls together. As long as the loads you want to help support are directly over the studs in your new wall you don't need a double top plate.

    How about this: Nail the top plate to the joists above. Nail a second top plate to that, and lap it at least one stud space. Fasten a bottom plate to the slab, and toe-nail the studs between the two.

  2. Expert Member
    Michael Maines | | #2

    Joe, is this an interior wall or exterior wall? I rarely use double top plates on interior walls, but practices vary by region and builder.

  3. PLIERS | | #3

    This is an exterior wall. From what I have read and seen everyone uses single top plate. A carpenter told me to use double for extra support. If I do use 2 top plates I’m thinking of starting with 16 footers on top plate and then staggering 8 and 16 footers underneath.


  4. joshdurston | | #4

    Sounds like you just building walls to finish the basement? If so they are basically just to give you something to hang drywall on. So your top plate arrangement isn't structurally important.

    I usually use a chalk line on the floor. I snap it on the floor and tapcon the bottom plate to the floor. I then make sure the wall is plumb by moving the top in or out as necessary and fasten it to the joists above.

    Try and minimize your use of wood, this may mean single top plates, and possibly 24" on center studs. More wood = less insulation.

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