Clay Roof Felt Paper

Hey everyone I have a house that is 6600 sqf and has clay tiles on it, two roofers have already inspected it and say that there is 15 pound under the roof and the builder is saying there is 30 pound felt.
The two roofers say that the 15 pound felt should have never been used and has a high rate of failure.
Does anyone have any facts on this matter archived deep in there computers?
And has anyone seen any legal mumbo jumbo on the can or cannot’s on the use of 15lb felt on the underside?

Thanks in advance

30 lb. felt is the requirement. Double layered if less than 4:12 slope. 15 lb. would be completely inadequate.

Tile roofs are like fiberglass flat roofs they can look perfectly fine but still leak a little. Take your time when inspecting one.

Ditto what Jeff said…!!

People need to put into perspective the tiles are for aesthetic purpose and to prevent the sun from destroying the underlayment.

So even if all the tiles were removed the roof should not leak, they are not there to prevent leakage, simple protect whats under them from the elements.

If 15lb felt is all that is under the tiles, it is not acceptable by any stretch of the imagination.

Double Ditto what Dale was agreeing with what Jeff said :wink:

30 lb miniumum, and that is a very poor miniumum :frowning:




You’ve already heard from 3 of the best and have 2 contractors that have identified deficient underlayment all I can add is this link with the standards you requested

To everyone who responded much thanks.
And Barry thank you for the link everyone links hard facts.

Thank you,

Troy Farmer
Presidential Inspections LLC
Po Box 2144
Eagle, Idaho 83616

Here is the NRCA link to this answer:

If you do not want to read the entire page, just click on “Underlayments” to take you immediately to that section.

Basically, it boils down to one layer of 30 # aka Type II felt for pitches of 10/12 and greater and 2 layers of 30 # for less than 10/12 pitch.

It is an interesting read for you guys.


Ed’s post reminded me of this

thanks Ed

National and Local codes in PA is 30# felt. Why don’t you just call the local inspector in your area?

The only time i have used 15# felt is between the subfloor and hardwood that is being installed.