No 15 felt and no.
Roofing underlayment 15 vs 30.
15 came perforated for use as a ply sheet for built up roofing.
30 felt is typically thicker stronger and may be less prone to tearing or ripping off during installation or weather events.
Therefore we do not hold that nails ruin underlayment as a valid argument.
Once the shingles are on the weight of the felt matters very little.
The difference between 15 lb and 30 lb roofing felt paper.
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.
Is synthetic roofing underlayment waterproof.
A high quality fiberglass 15 or a standard 30 will do this very well.
Many manufacturers produce asphalt saturated paper labeled underlayment 15 lb or 30 lb which do not comply with any standards and which are often saturated to a lower level than an astm compliant underlayment.
These underlayments typically absorb water more readily and fail sooner.
15 lb felt paper weighed 15 pounds per 100 sq.
Generally speaking roofing felt is a felt paper that is soaked in asphalt and other water resistant compounds to produce a membrane.
So even though the underlayment is water resistant you can t really call it waterproof.
What is roofing felt.
The main advantage of using felt roofing underlayment is cost.
Historically roofing felt paper was named for weight.
As of publication you can purchase a 72 foot roll of 30 pound roofing felt for around 15.
Synthetic roofing underlayments use cap nails or staples for the installation.
On lower slopes i feel more comfortable with the thicker felt.
Felt roofing underlayment is typically available in two types.
The biggest drawback to synthetic underlayment is the cost.
No doubt about it.
One roofing square and 30 lb felt paper weighed 30 pounds per square.
Of course it is a bit more technical than that but this is the basic idea behind how felt works.
30 is better for protecting your home during the re roofing process.
If you experience high winds and some shingles get blown off the felt will protect your home until repairs can be made.
If 100 the typical upgrade cost to go from 15 to 30 is going to blow a sale for you you are doing something wrong.
Asphalt saturated heavy duty roofing felt is available in 15 and 30 pound weights.
On steep roofs the 15 rips easily under foot.
