I have a 3′ cripple wall sitting on top of a 4′ foundation in my garage (built sometime after 1913) that I’m adding plywood to strengthen for the next earthquake.
The wall has three top plates. The bottom top plate is in the same vertical plane as the sole plate. The middle and top top plate are (+/-) 1/4″ to 1/2″ inch out of plane with the sole plate. The bottom top plate consist of two 10′ 2 x 6s. The middle and top plate are made up of multiple 3′ and 4′ long 2x6s. As long as all of the top plates are attached to each other securely does it matter which plate the plywood is attached to? Attaching it to the bottom top plate will save me the trouble of having to shim everything to bring it into alignment.
Thanks,
Matt
Replies
Ordinarily the shearwall is fastened to the outermost member - keeping it all inside the diaphram. The exception might be where another member is bolted to the diaphram edge.
With your situation, You would need 5/8" threaded rod every 4' with a 3" seismic washer (they are about 1/4" thick) bolting down the two upper plates to the bottom plate that you can actually fasten to.
You can't really "shim" a shearwall like you do drywall.
This is a completely innocent, non-malicious question for xxPaulCPxx: What is WYSISYG? I know of WYSIWYG: what you see is what you get. Thanks. I see you post a lot and value your input as it is professional and informative.
well, paul can almost spell.......
and all I can figure, especially on this forum is...........
What You See Is Sortawhat You Get.
New software you understand.
Sorta-
It's a couple years old and is hard to manage.
The story in my sig line was that when the Forum changed a year ago, I was very happy to have the new WYSIWYG editing. I think it took me a couple of weeks to realize I had spelled it wrong... fully committing to my mistake, I added the secong part about spell check!
And, of course, then it became impossible for many of us to edit our signatures.
Thanks Paul.
I've been bolting it ,following the method you described, in every stud bay and was planning on adding 40d nails - maybe that's overkill.
When I redid my kitchen I had a similar situation where the studs were set back and didn't line up with the plates. A structural engineer told my I could use wood glue and fur out the studs using 1/8 plywood.
I was thinking of doing this with the cripple wall but there are to many different pieces to line up.
Don't worry about the nails - it's the bolts that will keep the boards from pulling off the top of the shearwall diaphram.