DIYbanter - View Single Post - Exterior "soffit" wood nailed to old "soffit" wood than painted, will it cause problems?

Tony Hwang

wrote:
I need to paint the exterior of my house, everything is easy except
the "soffit" (I believe that is what it's called, it's the part under
the roof on the sides of the house that over hang), My house is old so
this part of the exterior is really thin plywood (without vents) and
has old (lead) paint that is peeling off (it can't be painted over). I
would like to try and avoid stripping it for obvious reasons....

What I would like to do is just cut and paint new plywood (on the
ground) and just nail/screw it to the old soffit plywood. I would like
to do this for 2 reasons: I wouldn't have to strip the lead paint and
the 2 pieces of plywood would provide more noise insulation.

What worries me is that moisture might get trapped between the layers
and rot out the wood. I am not against priming the old and new wood if
that will help protect it from moisture. Will this work? Will priming
be enough or do I have to design it so air can move between the
layers?

I am willing to go one step further if it will help and is safe; I've
worked with a sound barrier called Homasote 404. What I could do is
cut the 404 and install it between the 2 layers of plywood, would that
work? Or would it be better to cut strips of the 404 and stagger it so
air can move between the plywood layers?

Thank you

Hi,
For the effort, if I were you, I'd rip out the old part and install
aluminum soffit panels. It provides venting, last LONG without painting.