Installing Metal Roof Underlayment

The best underlayment for metal roofs.

Installing metal roof underlayment.

It provides a solid flat surface to attach the new metal roof to it creates an air gap between the back of the metal and the shingle roof which allows for airflow. On most projects there are two types of underlayments. Traditionally metal roofs have used standard 30 pound felt paper underlayment. Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof.

The first goal of roofing underlayment is to keep the roof deck dry before installation of the metal roofing material. A building envelope is. The roof is an important element of the building envelope. When underlayment is to be covered immediately with battens it can be secured with a minimum of fasteners to hold it in place while the battens are installed.

Lay the underlayment flat in place with the print side up. There are several types of felt underlayment including both organic reinforced and inorganic reinforced. Underlayment must also act as a secondary weather barrier in case the roof fails. Installing the correct underlayments for your metal roof project the right stuff taking care of your building envelope.

First two underlayment layers. Installing the metal roofing over 1x4 s allows the ability to also install additional insulation under the metal roof. The traditional and most common material used for roof underlayment on a steep slope metal roof is non perforated asphalt impregnated felt underlayment. Seal with adhesive sealant or tape as described in section 6.

Install final flashing material. Install the roofing screws vertically along each rib in the panel. Install underlayment a minimum of 6 inches up roof protrusions or vertical abutments. However contractors now recognize the benefits of synthetic underlayment for metal roofing particularly when it comes to its tolerance to heat and ultraviolet uv radiation.

The underlayment should then be cut to a length that can be easily managed. The synthetic component of this metal roof underlayment makes it tougher than its felt counterpart. Allow for about 3 inch side laps and 6 inch end laps. Place the first screw.

Be sure the larger edge is laid so that the small edge of the next panel will overlap it. Each roll of this product covers 1 000 square feet of surface area and the whole thing weighs less than 25 pounds making it lightweight and easier to transport.