Durable Window Installation Means Letting the Water Drain out
Rule #1 is to keep as much water out as possible. Rule #2 is to let the leaks drain out. Well-flashed window heads are the first line of defense. Sloped sills, backdams and pan flashing direct water out. There are many choices in sill pan flashing; in this video, Mike Guertin shows how to install flexible peel-and-stick pan flashing.