Roofing Felt Overlap Size

Roofing requirements roofing felt is required to overlap 2 inches over the lower felt course.

Roofing felt overlap size. Overlap the end of a roll about 4 inches with the start of a new roll and fasten both pieces to the. The vertical leg of the drip edge should be at least 1 5 inches wide and extend at least 0 25 inches below the sheathing. Therefore a 2 inch overlap provides redundancy at the edges where the barrier is weakest. However you must allow for overlaps on joints.

You can see the difference between the underlayment overlapped 19 inches on the roof to the right and overlapped 2 inches on the roof to the left. If there is any wind at all roll out the felt only about 10 feet. Pick up the roll with both hands. One roll of conventional 15 felt covers 432 square feet 40 1 m 2.

Never walk on felt that has not been nailed down. Purchase enough felt to cover your roof s area. Roll out the felt no more than midway perhaps 25 feet or so across the average size roof. In most cases this will leave 400 square feet 37 m 2 of net coverage per 1 roll.

The drip edge should extend at least 2 inches on the roof. Continue along the roof to the other end and trim the felt flush at the end with a utility knife. The spacing between the nails on the drip edge should be less than 12 inches apart. The overlapping felt creates a secondary barrier for moisture and wicks water away from the shingles above and the sheathing below.