How To Install Roof Underlayment

Step 1 safety.

How to install roof underlayment. 4 lay the membrane on the roof with the plastic. The lap is half the width of the roll plus one extra inch for headlap. Peel back 1 to 2 feet of release liner align membrane. Put on your protective eye wear and work boots before you begin.

How to install roofing underlayment. Be careful moving up and down the ladder. Install drip edge at the roof eave edges. Step 2 preparing the roof.

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. Apply drip edge to the eave. Start the roof felt at one bottom corner of the roof. 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. Step 5. 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. Back roll method cut the membrane into 10 to 15 foot lengths and re roll loosely.

Step 4 rolling the underlayment. Peel the release liner from the membrane. Overhang the roof rake edge 1 5 and cover the underlayment with a metal rake edge trim. The standard approach for two ply roofing underlayment is to lap a 36 inch roll by 19 inches.

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