Is it worth it to spar urethane over flat exterior latex paint?
I've got a small exterior wall, plywood surface that's been primed and painted with flat exterior latex. If I want to give this more protection from the elements (water, sun, freezing) should I coat with a spar urethane or would it be better to just build up extra coats of the same exterior grade latex?
At another DIY forum, someone suggested the same to me. He said that the flat exterior was a bad idea if I was looking for the surface to be water repellent. He said better to go with a satin or semi-gloss, which I just painted over the flat. He said this would give just as much protection as a spar urethane. Hard to believe, but we'll see. Thanks for your reply.