15 Or 30 Felt Under Metal Roof

Traditionally metal roofs have used standard 30 pound felt paper underlayment.

15 or 30 felt under metal roof.

The difference between 15 lb and 30 lb roofing felt paper. Of course it is a bit more technical than that but this is the basic idea behind how felt works. Other say need felt because of sweating and it will root the osb 30 felt or not. Make sure the product is designed to be used under metal.

Plywood or osb roof deck so 15 20 or 30 will work for any shingle roof the type i recommend depends on roof slope. Once again this is used on cold roof construction. There are several types of felt underlayment including both organic reinforced and inorganic reinforced. 30 felt is typically thicker stronger and may be less prone to tearing or ripping off during installation or weather events.

Generally speaking roofing felt is a felt paper that is soaked in asphalt and other water resistant compounds to produce a membrane. The best weight for roofing felt is the 30 pound product because it provides thicker and. Most codes and good roofing practice would require felt. Felt paper is commonly produced with a certain number of recycled products and coated with asphalt.

Asphalt saturated heavy duty roofing felt is available in 15 and 30 pound weights. Underlayment must also act as a secondary weather barrier in case the roof fails. When hot roof construction is done a roof with no ventilation a breathable underlayment is recommended. Historically roofing felt paper was named for weight.

That is the quesation. What is roofing felt. The house is in eastern tn. The best underlayment for metal roofs.

This type of underlayment is critical to a quality roof installation. The main advantage of using felt roofing underlayment is cost. The first goal of roofing underlayment is to keep the roof deck dry before installation of the metal roofing material. 15 lb felt paper weighed 15 pounds per 100 sq.

In my opinion felt paper is a vapor barrier plus keeps the oils in the shingles from leaching out and into the wood substrate i e. With metal roofing its also a good idea to put a layer of red rosin paper between the felt or ice water. One roofing square and 30 lb felt paper weighed 30 pounds per square. It serves as a moisture barrier as well as a slip sheet.

No 15 felt and no. Felt roofing underlayment is typically available in two types. In the old days common felt was 15 lb felt and 30 lb felt and a roll of the first held 4 squares and weighed 60 lbs while a roll of the second held 2 squares and weighed 60 lbs. 15 came perforated for use as a ply sheet for built up roofing.