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15 lb. or 30 lb. Felt?

I do appreciate the help from this discussion board regarding a new roof for my home.
It is not much more to upgrade to a 30 lb. felt underlayment as compared to the 15 lb.
Could anyone explain the pros and cons? Is there any reason not to get the 30 lb.? Since I want a quality roof, I am considering the 30 lb. but the contractor states the 15 lb. is just fine and that is what most people get.

Re: 15 lb. or 30 lb. Felt?

While #15 is minimum code in most places, I always put on #30.

My reason is simple: for an additional $100-$200 in material costs for an average size roof, I get twice the protection than with 15 lb paper at no additional labor costs.

Your roofer is trying to save that extra cost. Tell him that you will be glad to pay $100 more to have the 30 lb paper.

If you saw the condition of 15 lb paper after, say, 20 years, you won't want it on your roof. And you know what? that paper is your last protection against the elements.

A. Spruce
Re: 15 lb. or 30 lb. Felt?

If you are doing an overlay, absolutely, unequivocally, 100% go with the 30# felt! If you're working from a bare deck, then either will do the job, but 30# is far superior for negligible price difference. I personally only use 30# felt on all roof projects.

Re: 15 lb. or 30 lb. Felt?

Personally, I do not use felt. I install ice guard instead. It is a lot more expensive but less likely to leak. If you are going to use felt, us 30 #.


Re: 15 lb. or 30 lb. Felt?

If I were to use felt on my own home I would go with the 30# . There's few places where so little extra cost can provide you with so much extra protection for your home. And if you are in cold climes also opt for "Ice Guard" at the bottom; again little cost for a much better job.


Re: 15 lb. or 30 lb. Felt?

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