Felt paper or not under metal rofing.
15 or 30 felt under metal roof.
Underlayment must also act as a secondary weather barrier in case the roof fails.
Felt roofing underlayment is typically available in two types.
Of course it is a bit more technical than that but this is the basic idea behind how felt works.
The best underlayment for metal roofs.
It serves as a moisture barrier as well as a slip sheet.
The difference between 15 lb and 30 lb roofing felt paper.
15 came perforated for use as a ply sheet for built up roofing.
The traditional and most common material used for roof underlayment on a steep slope metal roof is non perforated asphalt impregnated felt underlayment.
What is roofing felt.
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.
Felt paper is commonly produced with a certain number of recycled products and coated with asphalt.
30 felt is typically thicker stronger and may be less prone to tearing or ripping off during installation or weather events.
One roofing square and 30 lb felt paper weighed 30 pounds per square.
Traditionally metal roofs have used standard 30 pound felt paper underlayment.
The best weight for roofing felt is the 30 pound product because it provides thicker and.
When hot roof construction is done a roof with no ventilation a breathable underlayment is recommended.
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.
Make sure the product is designed to be used under metal.
Historically roofing felt paper was named for weight.
Most codes and good roofing practice would require felt.
The main advantage of using felt roofing underlayment is cost.
Once again this is used on cold roof construction.
That is the quesation.
No 15 felt and no.
There are several types of felt underlayment including both organic reinforced and inorganic reinforced.
Other say need felt because of sweating and it will root the osb 30 felt or not.
Asphalt saturated heavy duty roofing felt is available in 15 and 30 pound weights.
This type of underlayment is critical to a quality roof installation.
Generally speaking roofing felt is a felt paper that is soaked in asphalt and other water resistant compounds to produce a membrane.
Felt is commonly sold in either 15 or 30 rolls measuring 36 inches wide.
15 lb felt paper weighed 15 pounds per 100 sq.
The first goal of roofing underlayment is to keep the roof deck dry before installation of the metal roofing material.
