Metal Roof Underlayment Requirements

Roofing underlayment roofing felt requirements.

Metal roof underlayment requirements.

This article series discusses roofing felt specifically addressing the roofing code or roofing manufacturer s requirements for use of an underlayment such as roofing felt tarpaper or other underlayment products beneath asphalt shingles and other. How well roof underlayment performs will depend on which type you use. Traditionally metal roofs have used standard 30 pound felt paper underlayment. Power driven metal caps shall have a minimum thickness of 0 010 inch.

12 roofing underlayment wind by mcm best roof underlayment for tile roofs. Becoming familiar with the metal roof underlayment options available can help you decide what s best for your commercial building. We recommend a polypropylene scrim reinforced underlayment made up of multiple layers. Felt details for various roof slopes amp.

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. At western states metal roofing we have been in the roofing industry for over 20 years and have encountered every type of scenario with both types of underlayment. For architectural metal roof panel systems a roof underlayment is required to help control water leakage through the roofing system during heavy rain storms or under snow melting conditions. Underlayment must also act as a secondary weather barrier in case the roof fails.

Make sure the product is designed to be used under metal. Whether you re opting for a traditional underlayment or a selfadhered option the average life span of a metal underlayment will vary depending on the product that s selected. We generally prefer the use of synthetic underlayment as it is more durable and will last longer. This type of underlayment is critical to a quality roof installation.

Underlayment shall be attached using metal or plastic cap nails or cap staples with a nominal cap diameter of not less than 1 inch. 13 1 frequently asked questions. It serves as a moisture barrier as well as a slip sheet. Overhang the roof rake edge 1 5 and cover the underlayment with a metal rake edge trim.

Metal caps shall have a thickness of at least 32 gage sheet metal. Choosing the right roof underlayment. 10 roof protector underlayment roll best roof underlayment for metal roof. Minimum thickness of the outside edge of plastic caps shall be 0 035 inch.