On 2008-04-06, RicodJour wrote:
On Apr 6, 11:52 am, Wayne Whitney wrote:

If you are in a high wind or seismic area, you may wish to consider
going over all the T&G 1x with 1/2" plywood to improve the shear
resistance of the roof. Of course, the wall sheathing would be more
important to strengthen, but it is presumably not accessible.

At $45/sheet? You're pretty free with the guy's money. The house has
been standing for 50 years, so there's little benefit to be gained
from an extra layer of sheathing. I also don't like adding weight to
a roof unnecessarily.

Hey, events that test the lateral force resisting system are typically
high magnitude low probabilty events like earthquakes or hurricanes.
So just because it has been standing for 50 years doesn't mean that it
isn't worth strengthening _if_ the hazard is high. Hence my preface
"if you are in a high wind or seismic area."

Yours, Wayne