JGS wrote in message ...
Zinesser makes a paint for materials exposed to dampness. I think it is
an acrylic latex and is guaranteed to prevent mold for 5 years +. JG


Generally speaking latex paints are permeable to water vapor. The
wood still 'breathes' and if water gets in to the wood through an
unpainted surface, like from above on a joist, it can evaporate
through the paint. That assumes the water only gets in rarely.

Many years ago my Dad had me paint the joists and subfloor in
our basement ceiling. It made a tremendous difference in terms
of brightening the laundry room and workshop. He had me wipe
the joists with a damp rag so that, in addition ot cleaning them,
the surface would be moistened and would not soak up quite so
much paint. The latex paint we used stuck well. I do not
remember the brand

A latex paint made especially for damp locations should be perfect
for your need.

--

FF