Is Roofing Felt Needed For Metal Roof

For steep pitched roofs felt is often not required.

Is roofing felt needed for metal roof. Roofing felt is a layer of tar paper installed beneath the shingles to provide a backup waterproof membrane in case of leakage. Synthetic underlayment is a newer innovation that is taking over the metal roofing industry as a better more advanced replacement for felt underlayment. Defer putting drip edge on angled gable ends until after the felt is laid so the metal edge will block wind from lifting the felt. Architectural metal roofs with felt underlayment are best suited for buildings with proper slope and low moisture loads in dry or arid climates.

By andrew hazleton updated august 20 2018 roofing felt commonly called tar paper is an important component of any roofing system. Roofing felt may be necessary for use with your shingles to meet a class a fire rating when shingles are evaluated for their fire ratings it is done on a small test deck with the roofing felt underlayment in place without this underlayment the shingles alone may not meet the class a fire requirements. Extremely dry environments are also one area where felt may not be necessary. Start the roof felt at one bottom corner of the roof.

With metal roofing its also a good idea to put a layer of red rosin paper between the felt or ice water shield and the metal that way it wont potentialy stick to it and cause oil canning and would allow for expansion. Roofing felt is always recommended but is not actually required by all shingle manufacturers. For each type of roofing material you can see the actual language used in the model 2018 international building code at the international code council website. Felt otherwise known as underpayment is required when.

Conversely felt underlayment is appropriate in conjunction with ice dam protection at eaves and other critical transitions in cold climates. Most codes and good roofing practice would require felt. Most synthetic underlayments are mechanically attached with roofing caps and staples while others have a glue backing.