How To Install Roof Underlayment

This provides two plies across the entire roof with three plies at the headlap.

How to install roof underlayment.

Press the membrane of the self adhering roofing underlayment in place with. 4 lay the membrane on the roof with the plastic. The standard approach for two ply roofing underlayment is to lap a 36 inch roll by 19 inches. Be cognizant of the.

Step 3 preparing the underlayment. Synthetic roofing underlayment is to be laid horizontally parallel to eave with printed anti slip side up starting at the bottom of the lowest roof eave with a 1 5 underlayment overhang at the eave covering the pre installed eave drip edge. Overhang the roof rake edge 1 5 and cover the underlayment with a metal rake edge trim. Install drip edge at the roof eave edges.

Be careful moving up and down the ladder. Put on your protective eye wear and work boots before you begin. Step 1 safety. Step 5.

Measure the underlayment to the length of the roof plus the 4 inches of excess and cut the membrane straight across with a utility knife or shears. Peel back 1 to 2 feet of release liner align membrane. Use a chalkline or align it by eye to make sure it is straight then drive roofing nails every foot or so to fasten it to the sheathing. Back roll method cut the membrane into 10 to 15 foot lengths and re roll loosely.

How to install roofing underlayment. Start the roof felt at one bottom corner of the roof. In roof areas where roof planes meet to form valleys which naturally channel high water flow in wet weather and other roof penetrations such as skylights plumbing vents roof to wall intersections are also important roof areas that can benefit from peel and stick membrane underlayment installation. Apply drip edge to the eave.

Step 2 preparing the roof. Minimum overlap guidelines are set by the. Tack it in place at the corner with the end flush with the end of the roof and the bottom edge of the roll right along the bottom of the roof. Step 4 rolling the underlayment.