30 felt is typically thicker stronger and may be less prone to tearing or ripping off during installation or weather events.
Roofing underlayment 15 vs 30.
No doubt about it.
15 came perforated for use as a ply sheet for built up roofing.
As of publication you can purchase a 72 foot roll of 30 pound roofing felt for around 15.
What is roofing felt.
One roofing square and 30 lb felt paper weighed 30 pounds per square.
These underlayments typically absorb water more readily and fail sooner.
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.
Once the shingles are on the weight of the felt matters very little.
Historically roofing felt paper was named for weight.
Generally speaking roofing felt is a felt paper that is soaked in asphalt and other water resistant compounds to produce a membrane.
Is synthetic roofing underlayment waterproof.
If you experience high winds and some shingles get blown off the felt will protect your home until repairs can be made.
Felt is commonly sold in either 15 or 30 rolls measuring 36 inches wide.
What this means is the fasteners can t be sealed properly.
15 lb felt paper weighed 15 pounds per 100 sq.
The best weight for roofing felt is the 30 pound product because it provides thicker and.
So even though the underlayment is water resistant you can t really call it waterproof.
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.
On lower slopes i feel more comfortable with the thicker felt.
The biggest drawback to synthetic underlayment is the cost.
Felt roofing underlayment is typically available in two types.
Therefore we do not hold that nails ruin underlayment as a valid argument.
The main advantage of using felt roofing underlayment is cost.
A high quality fiberglass 15 or a standard 30 will do this very well.
30 is better for protecting your home during the re roofing process.
Asphalt saturated heavy duty roofing felt is available in 15 and 30 pound weights.
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.
On steep roofs the 15 rips easily under foot.