I've got a screen-in porch that we recently painted the exterior using a
solid color deck stain. The interior, however, is not painted nor do I want
it to be as I prefer the natural wood look there. However since rain and
snow sometimes enter through the screens, the wood would need some kind of
protectant. I'm not sure what I should use, since the porch is 5 yrs old
already. Is it to late for a sealer (I have no idea if one was originally
applied), or should it just be cleaned periodically?