TruSlate ELK/GAF

Hi Everyone - New to this forum.
I’m a Roofing Consultant in Tampa Area of Florida. Been around 39 years.
I haven’t dealt with TruSlate by ELK/GAF, but boy I have one now.
Home (Castle) has a 19,600 s.f. roof (3 story home), with a 16:12 pitch.
There is a question I have about the vertical battens in the Valleys. I need to see if the installation guidelines have been changed after 2009, so if anyone has a copy dated BEFORE 2009, if I could obtain a copy, it would help me with the Homeowner to see what is happening. I am representing the contractor presently, but no one is talking anything but resolution.
Another issue I have is the polyethylene interlayment that is directly under the slate. It is growing. It has large wrinkles under the slate, but at the end of the 10-12’ sections, it is literally growing as much as 10+ inches into the valleys, curline up and looks really bad. We took 3 and 4 courses off, about 15’-20’ long to investigate. Laps that were 10-12" apart are now only as little as 2" where the product has pulled loose in both directions from the lapping. Craziest thing I’ve seen.

Does anyone have any comment, help, literature, or ??? that can help?
It would be greatly appreciated.
Roofguru in Florida

Your the Guru, you tell us. I dont know what the hell you or they used for an underlayment but it dont sound good. Even way up here in Mass. & NH under my slate roofs & metal roofs I either use Carlisle High Temp or Grace High Temp. Because even up here I’ve seen regular ice & watershield (peel n stick) underlayment melt under metal & slate roof systems.

Thanks for the response.

The problem I am seeing is a discrepancy in the procedures for valley flashings.
The documents from a couple of years ago mentioned and even showed vertical battens. The latest information does not mention them.
ALSO. The product I am describing is a polyethylene material that is placed directly under the individual slate pieces, and its called an INTERLAYMENT. This product at this site is “growing”. In less than 2 years, it had expanded laterally about 7-8 inches. It is expanding directly into the valley from under the slate. It is wrinkling under the slate. It is almost loose laid and has a very short headlap of 2". Thankfully, it is not moving in the Cross Machine Direction, only the Machine Direction.

I have in fact been doing the roofing gig for 39 years, never had the opportunity to be a contractor, but I am stumped by the product as I have not seen this particular method of installing slate. The pieces are pre-cut at 12" x 12" and hung on clips.
Very interesting and a strong learning curve.

I represent a contractor who may be headed towards trouble, and I need to help where I can by gathering information.

Any of you guys/gals who know anything about this system, or this product, please let me know what your experiences have been.

I was just messing with you before. However, now that i’ve read it again it does sound really strange.

I wish I could help but it sounds like they’ll be redoing the house with slate. I’m not too surprised a manmade product is failing once it got installed in the real world.
Most roofers like myself refuse to use it while slate is still available.

GAF Tru-Slate is not “man made”, it is actual quarried slate. In a nutshell it is 1/2" sized slates that are hung on a rack system and the head-lap is compensated with plastic “bibs” or “shims”. It’s marketed towards people that want and can afford the look of real slate but who’s home is not framed to properly handle the weight of full slates. Basically Tru-Slate is 1/2 the weight of traditional slate.

Personally I’d never install it, I’ve looked at it and I don’t like the system and I don’t like the way it needs to be installed (top down). That being said, I am pretty sure the system was introduced around 2009 so that may be why you can not locate a pre-2009 installation guide.

edit* Actually I have a Tru-Slate Pro Field Guide here that is dated 11/08. What’s it worth to you?! heh

File a warranty claim on the project. It sound like a material and possibly workmanship defect. The GAF sales office for your region is located right in Tampa at:

Roofing Southeast Sales Office
13361 N. 56th Street
Tampa, FL 33617

Being a roofing consultant, architect, or contractor makes it hard to know the ends and outs of every system out there. Use the GAF sales and technical offices to your benefit. You are a value to the GAF territory sales man, so they will be more than willing to help.

Not to worry TarMonkey. I know the slate remnants which are too small to be whole slate are real slate. Other than that, the entire system relies on manmade junk for underlay, headlap, etc.
Real slate can be installed on regular plank decking without any other considerations.

[attachment=1]DutchLapped Valley.jpg[/attachment]