Proper Installation Of Roof Underlayment

Overhang the roof rake edge 1 5 and cover the underlayment with a metal rake edge trim.

Proper installation of roof underlayment.

Roof underlayment prevents the roof deck from being exposed to the elements before or while the roofing material is being installed. Although this seems to contradict the overlapping principle installing the drip edge over the underlayment at the rakes creates a clean roof edge and provides the underlayment attachment with increased resistance against wind uplift. Install the drip edge on the gable ends of the roof after you finish installing your underlayment. Underlayment flashings and shingles all work together and must be installed in the correct order.

If you lay the felt perfectly straight you can use its lines instead of horizontal chalklines to align the shingles. Installing roof felt is a two person job. Overlap each row at least 3 to 4 inches. Use a tin snips to cut the drip edge to size.

If it gets wet it will wrinkle making it harder to shingle. 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. Using your staple gun secure the felt to the roof. Press the membrane of the self adhering roofing underlayment in place with heavy hand pressure to ensure the desired adhesion to the roof deck.

Ideally the roof covering material would be installed as soon as possible but in reality the roof may be protected by only the underlayment for days weeks or sometimes months. It s not ideal to install roof underlayments when the temperature is under 40 degrees f as it won t ensure a proper fit. Fasten drip edge on eaves with. The best time for installing roof underlayment is when the temperature is between 40 to 85 degrees fahrenheit.

Inspect the underlying roof sheathing for damage and make any needed repairs. Start at the bottom side of the gable and overlap the sections of drip edge a few inches as you work your way up the roof see figure a. Do not use felt as a temporary protection against rain. What is the best temperature to install a roof underlayment.

When going up the sloped edges of the roof called the rakes it goes on top of the underlayment. It is important to apply pressure to secure adhesion to the deck and to smooth out any wrinkles in the membrane that may result in air channels or tears that could result in a failure. Install a layer of roofing insulation as recommended by the roofing manufacturer. Nail metal drip edge flashing which bends over the roof and down the edge of the facing board on all roof edges.

Hammer down any large nails that are exposed by the removal.