On 2008-04-07, RicodJour wrote:

I understand your point about plywood adding to racking resistance,
but there's no indication in this instance - even if in a high wind
area - that the roof would benefit in any significant way from the
additional layer of sheathing. On the other hand DD's wallet would
be significantly lighter.

I'm not proposing that the plywood should or shouldn't be added, or
saying that it is or isn't worth doing. I'm mainly pointing out that
reroofing provides an opportunity to improve the racking resistance of
the roof structure, and that standards for roof construction have
changed since the house was built in the 1950's. So I think it is
worth checking what the current design loads are for that area, and
then evaluating whether the strengthening is worth the cost. You are
probably right that it won't be worth it, but neither of us can say
that definitely without knowing the design seismic and wind loads for
the OP's location.

Yours, Wayne