Asphalt shingles can be used on roofs with a slope of 2 12 to 4 12 if double coverage underlayment is used.
No slope roof underlayment.
Guide to roofing underlayment installation on low slope roofs with asphalt shingles.
On low slope roofs like you have a water proof membrane like i ws is good insurance.
Water that gets below both the roofing and underlayment will cause the same amount of problems whether it permeates the plywood or follows the pipe down.
The performance of this underlayment meets astm d226 astm d4869 standards so you won t have to worry about its quality.
Slopeshield plus self adhered roofing underlayment protects the roofing assembly by allowing vapor to pass through breathable but not air or liquid mitigating costly moisture damage and saving energy for the life of the building.
Ideally the roof covering material would be installed as soon as possible but in reality the roof may be protected by only the underlayment for days weeks or sometimes months.
It s constructed of a durable reinforcing mat of non woven glass fibers that have been coated and permeated to a thickness of approximately 2 0 mm.
The underlayment can make it through the summer heat winter snow and spring rain on a low slope roof without anything covering it.
Asphalt saturated felt along the eaves and lap succeeding courses by 19 inches as shown in figure 2 3.
Without further ado here are some good qualities of it.
So you don t have any idea about its characteristics.
That is why we like it to call the best roof underlayment 2020.
Slopeshield plus self adhered is installed on steep slope roofs of 2 12 9 46 degrees or greater pitch.
Start with a 19 inch strip of 15 lb.
With just one roll of this synthetic cover you are getting five times more coverage too.
It can be used on metal roofs steep slope roofs and all composite roof shingles asphalt based.