Hi all,

I have a house in the earthquake-prone SF bay area. My house was built in 1951. It's a split-level, 2-story house, with bedrooms above a large empty garage. I'll be doing the usual foundation bolting, shear panels in the garage.

But, I'm also wondering if I should do more, and add shear panels to the walls in the second-floor bedrooms. Currently, the exterior is stucco, with some narrow (maybe 6" to 8" wide) diagonal wood plank sheathing.

There was a long-unnoticed water leak at the corner of a window, and the wood sheathing rotted there (say about 1' x 1' area) so much that they basically turned to dust--I poked at them lightly and they just crumbled.

I know diagonal sheathing don't provide as much shear strength anyway, and that wall already has a huge window (the one that leaked), and now part of the sheathing has rotted out. So all of this got me wondering if I should actually put shear panels on the inside.

I believe that new construction usually puts plywood sheathing all around and outside the exterior walls--is that right? If I add panels on the inside, would that help, or should I really get someone to remove the stucco on the outside and do the shear paneling there?

 

I would consult a local structural engineer - too much depends on the exact situation for us to hazard a guess.

That said, I'll just note that all tectonic shocks travel through the ground.