Replies

1. 
   McDesign | Jan 12, 2009 06:24pm | #1

   I think so.  Our inspector allows a single top plate ONLY if every joist falls on top of a stud for all walls.  In your case, it's just a partition wall.

   Forrest

2. 
   JDRHI | Jan 12, 2009 06:24pm | #2

   The number of plates at the top (or bottom) have nothing to do with support concerns.

   They are used to allow connectivety of intersecting walls.

   For basements however, you might consider using metal studs instead of wood.

   J. D. Reynolds

   Home Improvements

    

    

    

   
   

3. 
   Hackinatit | Jan 12, 2009 06:42pm | #3

   Single is fine if studs under joists, double is easier for crown moulding installation

   A La Carte Government funding... the real democracy.

4. 
   DanH | Jan 12, 2009 07:09pm | #4

   Another point to consider is that in some places code requires a partition wall in the basement to be "suspended" vs rigidly attached to the floor. It's still pinned to the floor but can freely rise up a quarter inch or so to compensate for seasonal movement.

   God is REAL, unless explicitly declared INTEGER
1. 
   frammer52 | Jan 12, 2009 10:41pm | #5

   Dan, never heard of that.

1. 
   DanH | Jan 12, 2009 10:44pm | #6

   It was discussed here maybe 2 years back.
   God is REAL, unless explicitly declared INTEGER

2. FHB Editor
   JFink | Jan 12, 2009 11:56pm | #7

   hmmm, that's news to me, too. How would you do that? insert shims, nail, and then remove the shims or something?Justin Fink - FHB Editorial

1. 
   DanH | Jan 12, 2009 11:59pm | #8

   I forget the details. I'm thinking it used a double bottom plate, with the motion between the two.
   God is REAL, unless explicitly declared INTEGER

2. 
   florida | Jan 13, 2009 12:08am | #9

   I've seen it in Colorado Springs in every house under construction I've been it. Usually the basements are walk outs and are used for living area. They shoot a bottom plate down to the concrete and shim with pieces of 2" X 4" then build the wall with another bottom plate on top of that. When they're done they knock the shims out. It's very strange looking to say the least. I'll see if I can find a picture.

1. 
   craigf | Jan 13, 2009 01:58am | #13

   My BIL lived in a house with expansive soil under it. It rained one night when we were visiting. The BR door shut fine when I went to bed and would barely open in the morning.He was telling me the basement walls should be framed so the bottom plate was suspended off the floor, basically hanging from the joists. Metal pins in the floor went through holes in the plate to keep it from moving side to side. The floor was designed to float and the pins would move up and down through the holes.His house wasn't framed that way, so the basement floor would push the basement walls up. At least that was the way it was explained to me.

3. 
   Mongo | Jan 13, 2009 01:54am | #11

   I've seen that done in expansive soils like clay. The basement walls are poured, but the slab itself floats, it's not in contact with or connected to the basement walls. If the slab rises or falls a bit, the finished basement walls don't move, as they are suspended from the basement ceiling.Sort of like truss lift, but inverted!There are clips used that are similar to truss clips. They attach hard to the slab, but "slip" on the studs.I was a non-believer regarding slab movement versus the footings and walls not being heaved...until I was shown photos. Pretty impressive to see.And for the original poster, you also might want to consider using pressure treated lumber for any wood that contacts your concrete, like the sole plate.As to single or double cap plates, when framing a house shell if the framing is stacked I can use a single top plate. If the framing is offset (say studs 16" oc, joists 19.2" oc), then I have to double up the top plate.I always used a double top plate regardless. But that's for a house shell, not basement partition walls.Your basement walls are not load bearing, they are simple partition walls, so you don't need a double plate.

   Edited 1/12/2009 11:07 pm ET by Mongo

5. 
   Shep | Jan 13, 2009 01:23am | #10

   Another thing to consider when framing basement walls- according to code, you're going to need firestopping at the top so any fire in the wall can't get into the floor joist bays.

   I generally run strips of sheetrock around the room's perimeter from the sill plates out to where the wall interior will be. Then once you frame, your firestopping is done.

   On the wall parallel to the joists, I install cats, aka blocking, to hold the sheetrock, and also to nail the top plate into.

6. 
   Biff_Loman | Jan 13, 2009 01:57am | #12

   Yeah, you can go single top plate. But me, I wouldn't do that unless I was building the wall in place.

   You can go double: attach one plate to the joists first, then assemble a complete wall on the floor. When you stand it up, it's 1.5" shorter than your joists, so you can easily stand it up and coax it into place.

   Edit: Don't make it too tall! You can count on your concrete floor being uneven.

   
   

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   Edited 1/12/2009 5:59 pm ET by Biff_Loman

7. 
   9ENGEL | Jan 13, 2009 02:12am | #14

   There is no structural reason at all to use a double top plate, that big concrete thing holding the dirt back also supports the floor joists above.