Trivial question of the day: Need to insert partition wall with corner between 2 joists (floor is up, wall must go in before rough-in plumbing). This is also a place where people will be stepping as they enter the room. Due to various obstructions (e.g. steam pipe) I can’t block in the obvious places, so my plan is to lay a small piece of floor between the joists (12″x12″ due to sistering) to spread the load over 2×4 blocking. The 2x4s are notched 1/2″ in the center to avoid the steam pipe. Alternatives:
(1) piece of 2×12 on the flat
pro: gives me 1-1/2″ to screw bottom plate and subfloor to
con: I expect 2×12 will lose 3/4″ as it dries, and it may cup
(2) 2 pieces of 3/4″ ply glued and screwed
pro: it will retain its current dimensions (?)
con: only have 3/4″ surface for screwing into
The con for ply is based on the admonition against screwing a second layer of ply to the joists to which a first layer is screwed. Is this because of different expansion/contraction of the 2 layers? Can I ignore this for a 12″x12″ space, just glue-and-screw 2 3/4″ panels together and treat them as a single 1-1/2″ panel?
Replies
bump
Thats a tiring question.
What do you think is best?
blue
Warning! Be cautious when taking any advice from me. Although I have a lifetime of framing experience, some of it is viewed as boogerin and not consistent with views of those who prefer to overbuild everything...including their own egos
Additionally, don't take any political advice from me. I'm just a parrot for the Republican talking points. I get all my news from Rush Limbaugh and Fox and Friends (they are funny...try them out)!
The 2x4 blocking runs joist to joist?
The 2x4 is edge up?
The 1/2" notch is in the 1 1/2" face?
SamT
The 2x4s are edge up. The notches are about 1-1/2" wide and 1/2" deep. There's not much room for blocking with that steam pipe. So my solution is to spread the blocking load over several 2x4s. I may also nail tie plates into the 2x4s so they don't split down the middle.
I've decided to go with ply, because I don't trust the 2x12 not to shrink and cup and destroy that corner eventually. I'll glue two 3/4" ply panels together and screw that to the 2x4s. I understand now that the reason not to screw a layer of underlayment to the joists is to isolate it from movement of the structure, but that's not a consideration here, the real subfloor will go above this.
Now it's a matter of getting my right-angle drill attachment around that steam pipe and the BX cabling....
Taylor,
Where I come from, whenever we're going to place a partition between joists, we just nail 2x4 blocking 4" side up and flush with the tops of the joists.
Works on anything up and including joists 24"OC.
Place your blocks 2' OC and nail the party wall bottom plate to blocks whose location you have marked on the subfloor.
The total wall weight each block carrys is 2 studs and one sheet of DW.
Maybe, I'm not understanding you. Is this what we're talking about?
View Image
SamT
Sam,
Sorry this is off-topic, but I was wondering what program you used to draw that image?
Thanks
I use either Paint Shop Pro V3 shareware or MS Paint.
SamT
Sam, yeah, that's what we're talking about. I'm not worred about the load from the wall, I'm more worried about the half of this space that people will be stepping on as they come into the room (Edit: I'm worried about tile deflection over this space if it is not stiff enough).... There was a problem with putting a single 2x4 under the bottom plate of the partition wall: the joists were sistered with lag screws and the ends of the screws are sticking out right where one would want to attach the 2x4.... The location of the wall is determined since it is a plumbing wall.... This whole thing is a hack to get around one obstacle after another....
So my idea is/was to shift the 2x4 over and down a bit, and place a flat surface over the 2x4s to spread the load. The down side that I see is the notching of the 2x4s, but I can fit up to 4 2x4 blocks around the various obstacles and holding up the "load spreader"...
I'm screwing and nailing (4" screws and 16d nails) 2x6 nailing blocks to the sides of the joists, to hold up the 2x4s.... I've got 3" of sistered joists either side, too far to end-nail into the blocking from the other side.... And since the sister joists are higher than the original joists, there isn't enough surface to attach joist hangers.... I'll rest the 2x4s on the nailing blocks and use angle connectors to attach them to the blocks and the sides of the joists....
Edited 11/8/2004 10:58 am ET by Taylor