How do you nail down asphalt roll roofing?

How to Nail Down Roll Roofing Make sure that the roof is completely clean. Cover the valley of the roof. Nail down the 18-inch roll roofing sheet that it is covering the valley. Trim any roofing that extends beyond the edge of the roof. Place a sheet of 36-inch roll roofing directly over the 18 inch roofing that is covering the valley. Click to see full answer. In this way, how do you nail down roll roofing?Nail it in place with roofing nails spaced 6 inches apart and placed 1 inch from the edge. Measure and mark 35 inches from the bottom edge of the roof sheathing in several spots. Snap a chalk line along the marks. Roll out and cut roll roofing to cover the length of the roof.Additionally, does roll roofing need underlayment? While it is not necessary to install an underlay with roll roofing, it is inexpensive and adds a layer of protection that makes it worthwhile. Roll out the underlay and tack it down, making sure that it is flat and smooth, not buckled or wrinkled anywhere. Likewise, people ask, how do you do asphalt roll roofing? How to do it Roll Out Materials. Install drip-edge flashings, roofing felt, and WSU, if needed. Attach First Course. Attach Second Sheet. Spread Roofing Cement. Seal Vents. Overlap the Valley. Attach Final Piece. Optional: Adjust for a Sloped Roof. Can you install roll roofing over existing roll roofing?Roll roofing is made from the same asphalt composition material as shingles, and it’s easier to install. You can install roll roofing directly over a single layer of existing roof covering, but if there are already two coverings, you must remove both.