Synthetic Underlayments

jmorgan

Over the last few years I have noticed increasing popularity of synthetic underlayments. Last summer’s felt price increases spurred a major increase in the use of these underlayments out here in the West. I am looking for comments, both good & bad, from anyone who has experience with these underlayments. There are 4 main brands out there. Some are white and others are black. I have heard that snow does not melt off of the white ones. Is this a problem? Are some of the black ones too slippery? Do they “stretch” when installing on hot days? What happens when they get cold? How are they priced in your areas? Having installed 2 of the 4 products, I think these underlayments are the wave of the future....what do you think?
Jim

Grumpy

Jim, they still cost too much to experiment with out here in Chicago. Also I see new and improved labels slapped on the boxes just abotu every year which scares me. What was wrong with last years, or the year's before that?

jmorgan

Nothing was wrong with last year's. Most mfr's are constantly trying to improve their products. For example, if the traction of the surface could be made better at no extra cost, wouldn't that be something to include in the product that is good? With GIWS the addition of embossed, hot-melt surface improved traction greatly over old GIWS. The elimination of the fold on the side of the release paper and addition of a Ripcord for split release were other improvements added over the last few years. All of these features were asked for by roofing contractors. You're right though, it seems as if everybody always has "new & improved" products all of the time. Any other comments on synthetic underlayments. Grumpy, due to your knowledge displayed on this board, your comments are especially important to me,
IMHO,
Jim

Grumpy

I tell my customers this, because I believe it... When something "improives" every year it isn't stable. Asphalt felt is changed little, if any, and it's tried and true. When these sytnthetic felts stablize and go a few years without dramatic changes then I will start using them

Then the sales work begins... You don't want your house to be used as a test house do you? I know I don't want to gamble with your roof.

P.S. I am not talking about improvments like rip cords. I am talking about improvements in the chemical formulas which make up the actual membrane. Rip cord improvements are features which make a product better. When you change the chemical formula of a product you are changing the whole product.

Grumpy

Oh Yeah P.S.S. I do use ice shields like grace, and others on a daily basis. My above comments are in regards to the synthetic FELTS... not ice blocking membranes.

Ice blocking membranes like GIWS have been on the market since the 70's and had plenty of time to work out the kinks. They are fairly stable products at their current state.

jmorgan

I'm not sure, but I don't think that there have been any changes in chemical formulation since these synthetics were introduced 4-5 years ago. I believe that they are all spun-bound or woven polypropylene or polyolefen. I think most of the changes involved color or traction.
IMHO,
Jim

warpmine

I would only state the advantages of using the synthetics vs the organic felts is they don't expand and wrinkle up when rained on. The GAF product is pretty good for this along with price at about $25 a roll as opposed to $15 for 15 LB. Tensile strength is much better than organic and it didn't wrinkle up after days of rain so it dried out faster. Only disadvantage was that the fiberglass was all over you just like ply IV and VI BUR memebranes. Titanium UDL worked out nice but expensive($160 for ten sq). Fantastic anti-skid characterisitcs. Must be used with platic cap nails so hand nailing is a pia while a cap nailer will do wonders.

Grumpy

As I say all the time I'd never leave just felt exposed up on a roof without shingles, or at least a tarp over it.

jmorgan

Warpmine,
$160 sounds high for Titanium UDL. We get it here in the Rockies for about $110/roll (10sqs). Have found that the whitish color is a problem when dealing with snow, frost and winter roofing. The snow won't melt off.
Jim

warpmine

Jim: You could be right about the pricing but then again no here really has it except ABC and they aren't giving it away. Besides the suff is manufactured in British Columbia, Canada.

We haven't seen a winter just yet as it was spring last year at the installation.

Grumpy: Thats the nice thing about the synthetics you can walk away much more securely than with rag felt.

Doofus Emeritus

Mr. Morgan,

I have used the Titanium UDL on several projects with success, but snow does like to stick to it. One advantage is the footing is more solid than the organics, as well as tensil strength. The cost here in the peoples respooblik in N. California is competitive with organic #30, and won't blow off nearly as easy in a high wind. I also recently completed a state project using a product called Roof-Top-Guard. Another synthetic, but in black. Really slick when wet compared to the Titanium, but lays down really tight, unlike the Titanium. For those who are too proud and set in their ways to go with synthetics (and I really don't blame them), I have used Malarkey's SBS UDL on dozens of jobs. For an extra few bucks compared to #30 organic, it's a much better underlayment that won't wrinkle nearly as bad as #30.


Best regards

jmorgan

I've gotten some practice now. About 60 sqs TriFlex 30, 20 sqs Titanium & 10 sqs of Sharkskin. Some hand nailed and some w/cap nailers. Get to do 25 sqs of RoofTop Guard II sometime next week. Begining to develop my own opinions, but still very interested in your comments. We had another felt increase last week. If this keeps up, we all will end up having to install these products.
Jim

metalroofer

What do you think of tri-flex? we can't get it here in my part of FL, we do use titanium and that's all we put down now under our metal panels. I like it because it's light, won't tear and goes nicely over re-roofs as a slip sheet.

jmorgan

TriFlex is light, won't tear and also makes a great slip sheet. Out here in the Rockies, the grey color of Titanium makes it difficult to get snow & ice off prior to roofing. Can't see frost & dew on it. Triflex out here is black and does not have these problems. Also, I am a short guy and the 41" Triflex roll is easier than Titanium's 48" roll for me to install. Been snowing all week, so I haven't done my RoofTop Guard II job yet.
Jim

red_cedar

I use some of the synthetics, I do think they are the future.
What I do see as a potential problem is ventilation plays a much bigger part. If its not done right we are talking moisture problems.

jmorgan

Red_Cedar,
Why do you think that synthetics have any different ventillation considerations than, say, 30# felt. I believe that the perm ratings are about the same for both, but will check the synthetic mfr's web pages for perms.
Jim

red_cedar

Jim,
I have not checked with the manufacturers perm ratings, but will do so. The one I most have used is the Roof Top Guard series, with a litte Tri flex 30, of which I dont realy like other than the roll size.
The Roof Top Guard imformation comes from the distributor, a metal roof manufacturer. The stuff only breathes thru the seams.
I sell the underlayment with the belief that no moisture is going to get through the surface and no moisture is going out other than with conventional venting sytems.

An underlayment I have wanted to try to incorporate for some time is the 'Roofshield' About $400 a roll of apx 800 sq. ft.
the totaly breathable ( from inside to out only ) underlayment. But the industry, at this time,is going in the opposite direction with roofing underlayments.

ProSpec

Dear Grumpy - would you buy a new computer with technology that was 2 years old? 5 yrs old? 10 years? How about one that was say... oh 50 - 100 YEARS OLD? Technology marches on - like it or not. Titanium for example has gone through 3 primary changes since it's introduction. When first introduced it had a smooth "tacky" non slip surface. Great to walk on when dry but when wet - look out. Then they came out with the non-slip "nodules" which was a great improvement under wet or dry conditions. Recently they improved the nodules spacing and formation due to roofers comments about traction when on the balls of their feet. This has also been a great improvement providing your workers with and even safer working environment. If felt is so great why doesn't it come with a warranty? The synthetics give you 15 - 20 years. Your not using their house as a test roof - your giving them added value.

Jim

red_cedar

What are you doing on the computer Jim, you should be out selling some "ATAS" metal roofing

Grumpy

Would I buy a computer with 50 year old technology? Yes if it served a purpose and I was confident it did what I needed it to do. Would I sell my customer a 50 year old computer? Only if I was confident it was the best solution for their problem.

Why don't I sell the synthetics? You said it yourself. In the short time Titanium has been on the market it has been changed 3 times. Hmmm... to me that equals instability. Yes it's getting that "new and improved" sticker slapped on every box, which makes some happy; but it makes me cautious.

I have looked into quite a few different synthetics and I am even thinking of trying out a few, but my customers will not be the guinea pigs of any products because I am not going to slap my name or company name & reputation on a "maybe".