OSB Shear Wall Blocking 1

[SteveGregory]

I am requiring a contractor to go back and add blocking to about 8280 s.f. of shear walls.

1. Can a 2x4 placed flatwise be used for blocking the panel edges? The 2x8 studs are placed at 8" and 16" centers.

2. If some blocking is present behind one panel edge and the adjacent panel edge is not blocked, could another block be nailed to the 1st block and also nailed to the other panel edge?

 

[msquared48]

Regarding #1, 8d nails are 2.5" long, 10 d are 3". The thickness of a 2X4 flat and 1/2" CDX is only 2". If you clinch the nails this would probably be OK, but I would use 3X4 minimum flat or 2X4 on edge.

The answer to 2 is yes.

Mike McCann
MMC Engineering

 

[SteveGregory]

He is using 1.5" 16ga staples and the sheathing is 7/16", so he is getting about 1" penetration in the blocking.

 

[msquared48]

If that meets the shear requirements for the panel, then the blocking is OK flat.

Remember that flat blocking is allowed in a roof diaphragm, so it is OK here as long as the penetration is covered.

Mike McCann
MMC Engineering

 

[boo1]

Why nail the second block to the first, just place it next to the first and nail through the 2x8s.

why use staples? we prefer nails or screws

 

[SteveGregory]

Nailing the 2nd block to the first block "stitches" the panels together for the diaphragm action.

We got involved in the project after the walls were erected. They used staples. We checked the diaphragm with staples and it passed.