Underlayment felt #30 vs fiberglass

Hello roofing Gurus,

I was reading this forum for a while, but this is my first question here.

I am researching re-roofing project and at this point was offered to use fiberglass underlayment instead of regular felt #30. To be more specific I was refered to “Matrix UDL” fiberglass underlayment. Is there any reason I should not go with fiberglass?

What is your choice and why?

Thank you all.

i think youve been miss informed. i just did a search of that product and its not fiberglas. its a polyolefin based non woven product. Basically its just a synthetic underlayment. I use synthetic underlayment and they are great products but i dont know anything about that one in particular. biggest thing you will here from guys on here is to make sure its breathable. you want an underlayment that will shed water and moisture but still breathe as not to trap moisture below your roof. tho if you vent your roof at the peak like you should then you shouldnt have an issue even if it doesnt breath that much.

use a name brand synthetic felt never heard of this matrix udl… atlas’ summit is pretty cheap and proven

Thanks for replies. I guess I need to contact the supplier and ask what exact brand of this material.


its made by a company called fabrene. just google matrix udl or fabrene udl. they are the same thing i think.

Never heard of it but personaly use fiberglass felt over 30# saturated organic felt.

Haven’t we all learned that organic and roofing don’t mix? J/K! They used to make good organic shingles back in the 70’s and 80’s.

i did that and seen that just wasn’t sure, id rather be safe and use a product i know is good

I stick with good ole felt,unless i’m leaving roof open for a long period of time…which is unlikely.