Installing Metal Roof Underlayment
On most projects there are two types of underlayments.
Installing metal roof underlayment. First two underlayment layers. Traditionally metal roofs have used standard 30 pound felt paper underlayment. When installing a self adhered underlayment start at the lowest part of the roof deck and install valley conditions first. Seal with adhesive sealant or tape as described in section 6.
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. Lay the underlayment flat in place with the print side up. Install the roofing screws vertically along each rib in the panel. Installing the metal roofing over 1x4 s allows the ability to also install additional insulation under the metal roof.
What types of underlayment are available for metal roofing and which is the best choice for your design or installation. 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. There are several types of felt underlayment including both organic reinforced and inorganic reinforced. A building envelope is.
The traditional and most common material used for roof underlayment on a steep slope metal roof is non perforated asphalt impregnated felt underlayment. The underlayment should then be cut to a length that can be easily managed. The first goal of roofing underlayment is to keep the roof deck dry before installation of the metal roofing material. Install underlayment a minimum of 6 inches up roof protrusions or vertical abutments.
Place the first screw. 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 synthetic component of this metal roof underlayment makes it tougher than its felt counterpart. 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. 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. 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. Learn more about how to install owens corning proarmor synthetic roof underlayment.
Allow for about 3 inch side laps and 6 inch end laps. The roof is an important element of the building envelope.