Tar Paper Necessary Under Metal Roof

A special underlayment may be recommended by the manufacturers of specific roofing product and hybrid products.

Tar paper necessary under metal roof.

Metal roofing underlayment is unique in requiring an extra slip sheet layer which is typically red rosin paper. The slip sheet helps keep the metal from sticking to the felt paper while installing the roof. Long term in service roof performance can be affected by several important factors including. 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.

Our opinion is that on new asphalt shingle tile fiber cement slate and many wood roofs most roofing contractors apply an underlayment membrane of roofing felt tar paper or fiber reinforced roofing felt. It provides trapped moisture from under the roof in low slope applications a path to drain. Roofing felt is a layer of tar paper installed beneath the shingles to provide a backup waterproof membrane in case of leakage. Metal roofing panels rated for architectural use attached to purlins horizontal pieces of wood or metal fastened to roofing trusses are structurally sound when installed according to your roofing manufacturer s instructions and local building codes.

Usually 2 inches is plenty on a horizontal seam. Felt otherwise known as underpayment is required when. There are pre printed lines on the tar paper that help show you where to end the overlap. This thermal break promotes energy efficiency by stopping conductive heat transfer much like the air space between multiple panes of glass in a thermal pane window.

Felt paper or not under metal rofing most codes and good roofing practice would require felt. Sometimes called roofing felt underlayment roofing tar paper or roll roofing this is a layer of protection installed between the roof deck and the roofing shingles. The metal roofing system and its expected service life the climate at the building location roof slope and geometry and ambient conditions temperature relative humidity within the building. If you have a vertical seam where one piece ends and another starts make the overlap at least 6 inches.