Roof Decking and Fascia Repair

Under the shingles and the underlayment is the decking, plywood or OSB sheets nailed to the rafters, and it is what a roof is actually nailed to. Decking does not wear out on its own. It fails when water has been getting to it, from a leak above or from humidity below in an attic that is not ventilated, and once a sheet has gone soft it will not hold a nail and the shingles above it will lift in the first strong wind.

You can usually feel bad decking before you can see it: the roof is spongy underfoot in one area, or there is a visible dip in the slope from the street. In the attic it shows as dark staining on the underside of the boards, or boards that have delaminated and sag between the rafters. The fascia along the eaves goes the same way when gutters have been overflowing against it.

Replacing decking means stripping the shingles over the bad area, cutting out the soft sheets to the nearest rafters, fitting new boards and re-roofing that section. It is not optional, because a new shingle roof laid over soft decking is a new roof that fails early. Any replacement estimate should state what the decking allowance is, and any repair estimate on a long-running leak should say whether the decking was checked.

Whatever the problem turns out to be, the first step is the same: describe it, say where the house is, and one independent roofing contractor working in your town contacts you to look at it. No charge for being connected, and no obligation once he has.