Q: How do we prevent paint from peeling on our custom-built storm windows?
Paint alone isn't enough of a barrier to keep moisture out
Q: Our brick home did not have storm windows, so we made our own sash out of pine. We saved a lot of money, but on the bottom inch of each frame the paint is constantly peeling, despite frequent maintenance. How can we prevent this?
—Tom and Karla Jennison, Salt Lake City
Norm Abram replies: All wooden storms require regular maintenance, just as wood windows do. Perhaps you're having extra problems because the wood is absorbing moisture from masonry windowsills. Paint alone is not enough of a barrier to keep the water out.
At this point, you'll have to remove all the paint in the weathered area and brush on a paintable, water-repellent preservative like Wolman's Woodlife Classic. After you repaint the area, attach a scrap of self-adhesive waterproofing membrane to the bottom edge of the storm to create an additional barrier against moisture.
Another part of the problem could be that water vapor trapped between the storm window and the window itself is condensing and soaking into the wood. A couple of small weep holes cut in the bottom edge of the sash will give the water a way out. Aluminum storm windows have weep holes for that same reason. Make the holes about ⅛ inch deep and ¼ inch wide, and place them a few inches from each end. Just be sure that the waterproofing membrane doesn't block them.