How Much Overhang On Roofing Felt

Where a roll ends and a new one is begun the two rolls should be overlapped by four inches.

How much overhang on roofing felt.

Video of the day. Nail the bottom edges in place and then nail along the sides. Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest. Here phil explains how much overhang a roof should have at the gutter.

Roofing felt is required to overlap 2 inches over the lower felt course. Points to the first course of 15 roofing felt on this roof. Corrugated metal roofing generally comes in sheets that are 3x6 feet in size 18 square feet. Before you start to install corrugated metal roofing you need to figure out how much you need.

A conventional roll of felt is enough for 432 square feet. The overhang to the next strip should be 3 8 inch. A typical metal roof overhang may be 2 to 4 inches or even less. Make sure you have enough roof felt you don t want to have to stop mid way through the project to buy more felt.

Some slight overhang is recommended in conjunction with a drip edge flashing to prevent water from getting under the roofing and onto underlying wood. The drip edge should extend at least 2 inches on the roof. The lower edge of the felt is overlapped 3 4 on top of and over the upper edge of the lower course of ice and water shield. Just below we illustrate shingles installed with too much overhang into the gutter.

Greater overhang becomes a point of leverage for gusts of wind to rip off your roofing. Since you will have overlap between rows this works out to a total coverage area of 400 square feet the dimensions of a 20 x 20 roof. Measure the length of the roof and the breadth of one side. Multiply those numbers and then double the result for the square footage of your roof.

Metal is usually installed on rafters or strip sheathing rather than the solid decking used under other materials. The paper should then be nailed in or stapled every three to four inches across. All nails and staples should be placed on the lower half of the paper. About 1 inch just enough to assure the water goes into the gutter and not behind it.

The overlapping felt creates a secondary barrier for moisture and wicks water away from the shingles above and the sheathing below.