What types of underlayment are available for metal roofing and which is the best choice for your design or installation.
Is felt paper required under metal roofing.
Traditionally metal roofs have used standard 30 pound felt paper underlayment.
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.
Underlayment must also act as a secondary weather barrier in case the roof fails.
Roofing underlayment or felt is usually required for the ul fire rating to apply since shingles are usually tested with underlayment.
The addition of a slip sheet will increase the cost.
The traditional and most common material used for roof underlayment on a steep slope metal roof is non perforated asphalt impregnated felt underlayment.
Felt paper or not under metal rofing.
Might require a slip sheet a slip sheet is a layer of building paper that is installed beneath the roofing material to further protect the felt underlayment from damage or sticking that can occur when coming into contact with metal panels.
Most codes and good roofing practice would require felt.
Fifteen pound or heavier felt underlayment is required by code in some areas.