Raised Floor with 1-1/8" T&G plywood detail

[Cap07]

Hi,

Question - is the attached detail for a raised floor with 1-1/8" T&G plywood a good way to detail for transferring the shear through the wall down to the mudsill? Specifically, I'm wondering about the nailing of the plywood to the rim joist (with the required edge nailing for the plywood), then nailing the sole plate to the plywood. Thanks in advance for your input.

Cap

 

[Ron]

You seem to have some incompatibilities.

For the stud to sole plate, 4-8d's toenailed are not equivalent to 2-16d's end nailed.

16d's on 16 inch centers is a bit light for significant shear transfer. Are you in a low wind zone/seismic zone? Have you applied appropriate NDS factors?

 

[msquared48]

If the spacing of the 16d's to the rim joist becomes too tight, you can always use additional blocking or a double rim with Simpson A35's or LPT's from the additional blocking to the mudsill as required.

Mike McCann
MMC Engineering

 

[Cap07]

Thanks for your replies:

Ron: For the stud to sole plate, I didn't actually run numbers on that - I was just calling out what is listed in IBC Table 2304.9.1 (Item #8), but I'll check that out. My total shear load for the wall is 3500 lb (wind). Using an allowable of 141 x 1.6 = 230 lb, I would need:

3500/230 = 15.2 ----> 16 nails

So if my total wall length is 24', a spacing of 16" o.c. should work I think.

Mike: Please see the attached jpeg - is this what you mean? Won't there be some interference between the anchor bolts and blocking?

Thanks guys!

 

[msquared48]

YES - YOU CAN EITHER NOTCH THE BLOCKING OVER THE ANCHOR BOLTS OR SHIFT THE BLOCKING TO ONE SIDE. IF IT IS AN ADDITIONAL RIM JOIST, THEN NOTCH OVER THE AB'S. SORRY FOR THE CAPS. I GOT TOO FAR IN THE POST TO CORRECT IT. I AM NOT SCREAMING...

Mike McCann
MMC Engineering

 

[Cap07]

Thanks Mike

 

[msquared48]

Another point to consider here...

After the Northridge Earthquake, a change to the UBC was made that toe nailing was not allowed in UBC Seismic Zones 3 & 4 for any plate to diaphragm connections where the diaphragm stress exceeded 150 plf.

I Don't know if this applies to your locale and situation, but I just thought I'd mention it. I had to go back into my '97 UBC today and noted the posting and flyer I had saved.

Mike McCann
MMC Engineering

 

[Cap07]

Hi Mike,

Is this the corresponding section in the IBC:

2305.1.4 Shear panel connections. Positive connections and anchorages capable of resisting the design forces shall be provided between the shear panel and the attached components. In Seismic Design Category D, E or F, the capacity of toenail connections shall not be used when calculating lateral load resistance to transfer lateral earthquake forces in excess of 150 pounds per foot (2189 N/m) from diaphragms to shear walls, drag struts (collectors) or other elements, or from shear walls to other elements.

I remember reading this before, but I had forgotten about it. Thank you for the reminder.

Wind is the controlling case for this structure. It's a one story house in a high wind area.

I did call out A35 clips from the rim joist to the sill plate.

Thanks again for your help.