On 2008-04-07, Harry K wrote:

Well, if the winds and sheer force are great enough to rip off T&G,
a bit of ply over it ain't gonna stop it.

It's not a matter of ripping off the T&G boards, it's a matter of
deforming the framing so that each rectangle formed by two joists and
two of the T&G boards becomes a non-rectangular quadrilateral. This
only requires that the T&G boards slide relative to each other.
Plywood would resist this deformation much more than the individual
boards do.

Yours, Wayne