Synthetic Roof Underlayments

[patrick]

Any of you have experience with Synthetic Underlayments like Tri-Flex 30, Titanium UDL, Typar RoofWrap 30, or Shark Skin. The increased tear resistance, wide rolls, and fewer wrinkles make them sound appealing, but I was wondering if there's any downside besides higher cost. Please tell me what product(s) you've used and what was your experience. What are you guys paying per square for these products?

Thanks for the help.

patrick

[skydiver]

roof top guard II 5 foot wide, wont tear, easy to walk on, shrinks alittle, so the valleys have to have slack in them, wont wrinkle up with moisture like tar paper, the slight wrinkles will be tight in acouple days in the sun. has x/s where the nails go.. light weight. very nice $145 10 squares...tony

[Wes]

I use the Titanium UDL, 10 squares per roll and one roll weighs less than a roll of tar paper. This stuff is so superior to tar paper that you can't compare the two.
Tar Paper 30lb $15/2 squares
Tit. UDL $140/10 squares

Tar Paper: tears easily, wrinkles when wet, slick when wet, painted lines always seem to very roll to roll, very poor holding power even with caps, very hot to work with, takes five times as many rolls to cover the same area, won't hold up in wind, can only be left exposed for a couple of weeks, is just plain messy to work with.

Titanium UDL: won't tear, must be cut with a knife, doesn't wrinkle when wet, has some traction under wet conditions, every roll is identical, exceptional holding power to capped nails in high winds, less trips up and down the ladder for more rolls, easier to work with due to lighter weight, cooler to the touch because it is white, can be left exposed up to six months, chalk lines are easy to see.

We started using the synthetics earlier this year on a couple or roofs and will never use tar paper again on a roof. We have high winds on a regular basis and this stuff withstood 50-60mph winds during heavy thunderstorms and never even flinched. If installed correctly you will make up the difference in price in your labor, the added security if storms come up and your guys will thank you for not having to haul roll after roll after roll up the ladder.

We used it on a 14x12 pitch roof and I was able to run up it without slipping or tearing the wrap, lets see tar paper due that.

[patrick]

Good posts. Thanks guys. Anyone else care to weigh in?

[LarryD]

I suppose it really depends upon what time of year it is and what part of the country. I like Titanium for the summer, spring and fall here in N. IL but it really doesn't work very well for the winter months. I use the black Roof Guard II in the winter although I think that it's not as slip resistant as the Titanium would be on a dry roof. We need the black to burn off the frost or snow and the white or lite gray of the Titanium to stay cooler during the summer.

[Housewright]

We like tri-flex 30, only synthetic we have tried, far superior to papers, roof deck must be vented though.

[SolarPowered]

Be aware that Titanium UDL (& I suspect Tri-Flex 30, although I haven't looked at it) is a vapor barrier, while building felt is not. Depending on the design of the roof system, Titanium may trap moisture in the roof structure, leading to mold and rot. Something like RoofShield, on the other hand, is designed to be highly permeable to water vapor, allowing the roof structure to dry. Just randomly substituting one or the other for building felt could cause major problems, or produce a better-functioning system, depending on how the roof system is designed to operate.

Picking a particular underlayment because it's nice to work with during a particular time of the year is all well and good, but the material from that point forward stays in the roof for all four seasons of the year, every year. You're producing roofs that have vastly different performance characteristics, and you're rolling the dice as to whether or not they're going to work, unless you carefully analyze how they're supposed to work.

[charles]

What is this "RoofShield" you speak of? Since asphalt shingles are not permeable, I can't see why the permeability of the underlayment would be important.

[SolarPowered]

I hail from sunny California, where wildfire is an annual event. We tend therefore to have a lot of tile, fake slate, and even some real slate. Those do breathe, and the underlayment does make a difference.

In the U.S., RoofShield comes from www.vaproshield.com. It's an underlayment that is designed to be permeable, to allow roof structures to dry to the exterior.

I'll add the disclaimer here that I'm not an expert on this subject--I've been researching it (and other matters relating to building performance), but only know enough to know that it's important in some systems. Particularly with unvented attics, where you may want the roof structure to dry to the outside.

[charles]

Interesting. I must tell you that Joe Lstiburek, in his paper on unvented roofs, recommends *impermeable* underlayment. But perhaps he is anticipating asphalt shingles.

[Jeremy]

It has been a few years since we used Triflex 30. The first few projects were add-a-levels, and the final roofing material wasn't going to be installed for a week or two. The stuff held up great to very hot days and a couple of heavy thunderstorms. Then we used it on a large church project. The weather report said fog overnight so we tarped the roof with some 30x30 tarps over the Triflex so we could snap lines the next morning. When we untarped the roof the next morning the Triflex was dry, but within minutes it was damp from the fog. It was like ice and one of our guys slid down the roof and landed 20' down on the ground. We havn't used the stuff since. I don't know about some of the other makes. It holds up great, but use roof jacks and such if it's damp.

[patrick]

Thanks to all who answered. Does anybody have a price for a roll of the Grace Tri-Flex 30?

[Ralph-Eric]

One drawback of most synthetic underlays are the fact that the nailhole sealability performance is usually less than for bituminous felts. Due to the carpilarity effect, synthetic underlays require additional attention when installing. Cap nails generally need to be used instead of staplers and in some cases adhesives are needed at the headlaps.

[frogskin]

One drawback of most synthetic underlays are the fact that the nailhole sealability performance is usually less than for bituminous felts. Due to the carpilarity effect, synthetic underlays require additional attention when installing. Cap nails generally need to be used instead of staplers and in some cases adhesives are needed at the headlaps.

i can assure you that Rooshield's nailhole sealability is not in question, as you can see from this picture, all of VaproShield's products including Roofshield, have the ability to "sinch" around any fastener

[Adam Smith]

We have been using Grace Tri-Flex 30 alot lately. Just used it on a 12/12 pitch roof. It was a truss roof so we sheathed it bottom up, and then papered it top down with our toeboards coming off as we came back down.

It really seemed easier to go top down with the Grace in part because it is so light and won't tear. Makes it alot easier lapping the seams...always end up tearing the felt or the wind catches it or something