How To Install Roof Underlayment

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

How to install roof underlayment.

Step 1 safety. Step 3 preparing the underlayment. Step 2 preparing the roof. Press the membrane of the self adhering roofing underlayment in place with.

Be careful moving up and down the ladder. Step 4 rolling the underlayment. Peel the release liner from the membrane. Be cognizant of the.

Back roll method cut the membrane into 10 to 15 foot lengths and re roll loosely. 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. 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. Overhang the roof rake edge 1 5 and cover the underlayment with a metal rake edge trim.

Put on your protective eye wear and work boots before you begin. Peel back 1 to 2 feet of release liner align membrane. Cut drip edge flashing at an angle at the corner press it lightly against the eave end not too hard or you will misshape it and drive a nail near the end. Install drip edge at the roof eave edges.

Minimum overlap guidelines are set by the. 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. Start the roof felt at one bottom corner of the roof. The standard approach for two ply roofing underlayment is to lap a 36 inch roll by 19 inches.

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. The lap is half the width of the roll plus one extra inch for headlap. Step 5. Apply drip edge to the eave.