If you have a steeply sloped roof you can use the thinner one the 15 because rain will quickly run off the surface and not hang around doing damage.
Roofing underlayment 15 vs 30.
When it comes to your roofing you will have multiple decisions to make including what type of underlayment or felt to use.
Felt roofing underlayment is typically available in two types.
Felt underlayment requires more weight than synthetic underlayment to cover the same area.
The underlayment can make it through the summer heat winter snow and spring rain on a low slope roof without anything covering it.
Anywhere from 40 100 grams per square meter.
What is synthetic underlayment.
On steep roofs the 15 rips easily under foot.
On lower slopes i feel more comfortable with the thicker felt.
Felt is commonly sold in either 15 or 30 rolls measuring 36 inches wide.
When you compare the typar to traditional 30 felt roofing paper you can quickly see the advantages to using it.
No doubt about it.
Now however you also have the option of synthetic underlayment sometimes referred to as synthetic felt.
The typar surround s r.
The typar is 10 times stronger and 10 times lighter than 30 felt.
Weighs 16 to 27 pounds per roofing square.
Synthetic underlayment was developed as a felt.
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.
Roof underlayment 33 comes in rolls that measure 45 by 53 4 feet.
So you will get more of a protective layer if you use the thicker one the 30 however you have to consider how much weight you want to add to the roof.
And this synthetic roof underlayment becomes famous due to its quality easy installation process and affordability.
Traditionally you could choose between 15 pound and 30 pound felt.
These underlayments typically absorb water more readily and fail sooner.
Weighs 7 5 to 12 5 pounds per roofing square 30 felt.
Felt underlayment 15 felt.
Long ago a 15 role actually weighed 15 pounds but over the years that has changed.
Of course it is a bit more technical than that but this is the basic idea behind how felt works.
Because it s thicker and stronger 30 pound felt is a better choice than 15 pound felt for roofing.
Synthetic underlayment for durability and enhanced water resistance some roofers are going with.
No 15 felt and no.
