Organic felt or Shingle-Mate underliner

Hi all,

I live in the Atlanta, GA area and am getting quotes to re-roof. I’m down to two competitors, both with great reputations.

One is telling me to use organic asphalt felt underlayment, and not to use any of the new stuff. The other is telling me to use shingle-mate, and that it is great, they have not had any problems with it.

The shingle I’m considering is the GAF slateline, or perhaps the GAF timberline 30.

Any recommendations on the underlayment, or shingle?

Thanks in advance,


I feel Shinglemate is a far better product than standard felt.

Slateline is a better shingle and has a 40 year warranty. Plus your not like everyone else on the block.


Thanks much for your advice. I double checked the quote. They are quoting the following: direct from quote: “number 30 UL rated felt as an underlayment known as 60 lb. (28 lbs per square) fasten with plastic caps”

That all sounds condfuding to me. I think code is 15 lb, I understand 30 pound is better, but are they quoting me 30 pound, or 60 pound? If 60 pound, is shingle-mate still better than 60 pund?

Many thanks,


hey denardus,
when you here fifteen it usually means 2 plys of fifteen which equals one layer 30lb.
they usually do the 2 ply fifteen on lower slope roofs.
but to me i doesnt matter what ya use for underlayment the shingle and only the shingle is your roof.
ill put it to ya like this.
what ever a roofer has, extra of, for underlayment, in his wharehouse is what hes gonna like usin, the most, for the next job…


SHingle mate is a fiberglass style felt, it is equal to a 30 pound and is very tear proof and very water resist. For the extra few dollar it cost its well worth it. I swear by the fiberglass felt and it is all i use.

Lets put this one to bed shall we? I’m reading from the Certainteed (not GAF, but still) Shingle Applicators Manual, 7th Edition… “Why is shingle underlayment required? Certainteed does not require that shingle underlayment be used under their shingles for the standard shingle warranty coverage to be in effect on slopes of 4/12 or more.” Hmm… can’t even get a manufacturer to explain why its needed. It does say that it serves as a backup in case of blow offs, has some fire resistance, and is used as a temporary roofing system during the roofing process… but, what sticks out formost in my mind is this statement, “Because many contractors and their customers tell us they and their customers believe it is an important part of the roof system.” In other words, hook, line, sinker, we’ve been taking the bait for years. I only install it because I dont want someone to drive down the street and say “hey, look, no paper. what hacks.” Paper is a hoax, don’t let that be your deciding factor.

is a hoax.

I am in a roof every night pulling fiberglass back that is plugging rafters. The cellulose up there is wet cause it is leaking all over and the pine boards quite a few are all stained and wet.

Seems to me once the shingles got trashed and am sure cause no air could get through as it was plugged tight, not just with loose glas but also glass in paper stuffed in that some kind of paper would have protected it much better.

Yes it should have been reshingled earlier.

There is a carpenter a block away who did his whole home in ice and water, his own home so he could afford to do so, he said it seals around every nail.

Does the tar paper not protect from leakage? If so I would have found alot less damage here, Hopefully the pine roof will dry out and not have to replace too much.


You said it, not me. The roof should have been reshingled sooner. I pulled off a roof last year RIGHT ON THE OCEAN, 20 year shingle, at least 33 years old, no paper, never leaked, perfect sheathing. An ocean property that didnt even leak in hurricane Gloria (1987?) which is the worst we had up here since I’ve been alive. The roof was nailed right presumably with a good shingle and had plenty of ventilation. End of story. Ice and water barrier does seal around the nails. Its dummyproofing for roofers. I dummyproof by keeping dummies off the roof. The contractor that you are referring to does new construction and the ice and water is standard now for new construction because its a reliable temporary roofing system that they can count on while finishing things inside. For day to day roofing operations, tar paper cost $3.50 per square for materials whereas Grace Ice and Water barrier cost $65.00 per square… I’ll do it, but it’s not coming out of my pocket and I WOULDN’T spend it on my house because I know how to roof and I KNOW it is not going to leak without it for the life of the shingle. This is like the theory of dumbing down what they teach in schools because kids are failing. Just because they get straight A’s learning multiplication in middle school doesnt make them smarter.

easy s&g,
i know felt isnt needed for a roof to work, but it does have it benifits.
like a more secure work surface then bare wood (just lay shingles on titanium once and your sold). not to metion cant allways get it shingled back the same day and need a temp cover. and the newer underlayments nailed on with a good metal, round, ringshank, capnail are not going to blowoff as easyand in fact create a better 2nd layer of defence should the shingles come off in a storm.