Comparison of synthetic underlayment

The roofer switched out my agreed upon underlayment, we agreed upon GAF Deck Armor but when I visited the job site they had a roll of Berger Pro-Master Roof Shield UDL.

I questioned the roofer about it and he was quite defensive. He claims they are the same product, just made by different companies, that he tried to order the GAF at the last minute but they were out of stock and they provided this as a equivalent alternative.
Its seems to be made by a reputable company with similar spec sheet. Other than being piqued that the roofer didn’t disclose this upfront should I be concerned? Does this product provide similar performance and breathability?

I am being charged a $330 upgrade fee over 15# Felt for a townhouse which would use less than 10 squares (1 roll). Does this price make sense, and are the Gaf and Berger products comparable in price?

I also found it strange that the roofer claimed he had never heard or used a synthetic underlayment until I requested it specifically. How common are these products in the industry? I am an engineer so I tend to examine things closely, and I could see the cost/benefit of this underlayment, but I don’t know if its common practice yet or not.

I have no personal experience with the Berger product, I have used Deck Armor.
Looking at the Berger website I would say that they are equivalent products.

The only time we use a synthetic underlayment is if the roof is going to be exposed for an extended amount of time.
It stands up to high winds like no other…
I personally have no other use for it and do not try to sell it.
If the customer requests it, I will provide it.
My synthetic of choice is Titanium UDL.
IMO Titanium UDL is equivalent to Deck Armor.
If for some reason Titanium UDL was not available I would substitute Deck Armor, And I would have to give the same explanation as your roofer is.

** Your roofer is not trying to pull a fast one on you, I believe his explanation.
I doubt if he saved any money on the Berger product, it may have even cost more…**

I don’t push the synthetics because I don’t believe that they provide a tangible improvement over a quality fiberglass felt, or 30#.
They cost much more.

It is a better product, but the purpose it serves doesn’t require a better product in most cases.
Maybe under a metal roof, but not shingles.

There is no good reason to deviate from time tested and proven felt. Yes we have tried all the synthetics and will not use them again. Just more hype to sell more Kool Aid.

to aapocketz:

We use only DeckArmor for all our pitched roofs - we only install metal roofs, and breathable underlaymet is a must, since other synthetics trap moisture and act as vapor-barrier, causing in some cases mold and mildew growth in the attic. Felt on the other hand is very breathable ( although not as good as Deck Armor), and cheap - however unsuitable for us.

So in this case if your roof is poorly ventilated, you might have problems down the road.

Price wise, $330 up-charge is very reasonable as your roofer will need 2 roll of underlayment, so that $330 covers the material cost.

Bottom line, you really did not need synthetic for shingle roof. It is a good protection, but you need adequate ventilation with it. And the price is more than fair since it only covers the material cost.
Good Luck

we do support the use of high performance underlayment if the customers budget allows it. It has a higher tear strength. It is breathable. It can be exposed to more weather for a longer period of time. It creates a safer work surface. It will provide better protection provided a wind blow off of shingles. I could go on and on. In my opinion berger and gaf deck armor are about equal as far performance wise. As far as safety I think Gaf will someday get sued for making a product that is as slippery as it is. I use eithier certainteed, roof top guard, or titanium those three are like velcro under your feet. Gaf deck armor is like ice in comparison. Anything that provides the benefits that high performance felt paper provides should be used. Well at least the customer should be informed so they can be educated and make such a decision. In fact certainteed will give you a material and LABOR(leak free period) warranty if it is used under thier shingles. Provided one of thier certified contractors installed the roof. That there alone should tell you something about the product.

shingle mate is about the same price as 30lb felt when you do the math 30lb felt costs 15.00 per 2 sq and shingle mate is 24.95 per 4 sq so actually shingle mate is cheaper. Another thing i noticed is that no 15lb felt is good over the years man it just tears way easy i have a spotfire cap stapler and i use it always every job and the 15 just tears man i hate it and we like to walk all our roofs up to a 8/12 in pittsburgh most roofs are 8’s to 12’ and the shingle mate i use less caps and man i can walk a 10 with it cuts nice and we use hook ladders alot to get to other sides of the roof instead of toe boards and the hooks dont even tear the shingle mate up that bad