I’m looking for advice on how to fix this mildew problem on my deck. The exposed beams are painted with exterior latex paint and they have mildew on them. Once a year I get up on a ladder and use a mildew spray to clean them up. This is getting less fun each year and I’m looking for something to stop the mildew in the first place. I want to know if I repaint with a mildew resistant paint will that work? Should I change the color so the mildew doesn’t show? How should I prep the wood if I repaint? I can’t pressure wash or spray water in this area, it’s all by hand. Thanks!!
Replies
Get rid of the moisture
The mildew is growing because it has enough moisture to do so. Mildew resistant paint might do the trick, but I'd also look for moisture sources below the deck such as downspouts. If you have access, a few inches of clean crushed stone below the deck can short circuit ground moisture, although gravel won't do much if there is water that drains to below the deck. Of course, if you live south of Ontario and east of the Mississippi, or in the Pacific Northwet, then it's likely just a result of ambient humidity and you're stuck with either a mildew resistant paint or regular cleaning.
You need a mildew-resistant paint. Either a paint advertised as mildew-resistant, or you can buy an additive that makes regular latex paint mildew-resistant.
You'd face the same issue in a bathroom, but in your case the problem is not so much the humidity per se, but rather the sheltered nature of the application, since sun cannot strike the mildew to kill it and rain does not wash it away.