Roofing
A roof begins with the deck, the boards or panels fastened across the rafters, and its condition decides how well the rest will hold. Between deck and covering lies the underlayment, which turns away water that gets past the top layer, and it is the backup layer that does the quiet work. At each chimney, wall and vent pipe, flashing does the sealing that shingles cannot, and it fails when sealant dries out or metal bends loose. The covering on top is what people picture when they think of a roof, though it is only the outermost layer, and it works only as well as the layers below it. A ventilated attic lets hot air escape through the ridge or vents while fresh air enters at the eaves, and it also helps the attic dry out after a damp spell. Drip edge and gutters take over where the roof surface ends, and a missing or bent drip edge can undo the work of the gutter.
