How do I install a roof vent over three layers of asphalt shingles?
Q I’d like to add roof vents to my house. There are three layers of asphalt shingles; the top layer is pretty new. Do I have to go down to the bottom layer to install the new vents? D. Peters, Grafton, WI A Weave the vents into the top layer of shingles, but make sure you have a solid base left in the old layers after you cut the vent hole through the roof. The old shingles are brittle, so cut carefully. Fasten the vent with nails or screws that are long enough to pass through the old shingle layers and into the roof sheathing.
