I’ve got a contractor who wants to substitute (1) Siplast PA 1125 asphalt primer, (2) Siplast P-20TS torch applied, (3) Siplast P-20TG torch applied over densdeck, (4) EPS, (5) polyio over that, (6) FiberTite (a Seaman product) loosely laid, heat welded seams,and (7) stone ballast. The originally specified roof was modified bitumen. And he’s claiming he can give a manufacturer’s standard 15 year NDL warranty.
I’d appreciate hearing any thoughts on the system or products…or contractor.
Thanks.
Maybe I need an education here, but why get so complicated?
Not sure what an NDL warranty is, or if it is better than the roofing manufacturer’s warranty-- can’t see roofing folks warranting a mixtue of products, unless they agree.
I’d “stick” with a complete Siplast or Siplast approved system and require their warranty.
Just one opinion!
NDL = No Dollar Limit
And, I agree with Ralph; keep it simple and don’t mix systems. It prevents the multiple finger pointing if (or when) something goes wrong.
When was the last time a Contractor did anyone a favor? Beware of strangers, I mean Contractors bearing gifts!
If the contractor wants to put stone ballast on a roof which was designed for modified bitumen, be sure that the roof structure will take the additional weight.
Also I agree, why not just use the Siplast system, without all the extras. Keep it simple.
This sounds like a roofer that has materials leftover from six different jobs and wants to get rid of them all in one place. Where did this system come from? Is it in Seaman or Siplast literature? Who is giving the warranty? Siplast? Seaman? The Contractor (don’t think so)?
I had the same thought. Looks like this could be an effort to get rid of all those disparate leftover materials from different jobs (or worse, materials that weren’t really “leftover”…)
The contractor should be required to provide a structural analysis for review along with substitution submittal. The contractor should also pay the additional time required for the review. If one tells this to a contractor, he usually drops his request.
Lynn - I would want a roof assembly that matches one appearing in the Factory Mutual Global Approval Guide - that means that the manufacturer has experience with the system, has tested it, and has trained tech reps and installers who know it when they see it. I don’t know if what’s being proposed is approved. In fact, I’m confused about it. I take it this is going over a concrete deck (hence the primer and the venting base sheet). The Dens Deck material would be a cover board on top of the insulation sandwich (cheaper EPS topped for some reason with polyiso) over which the PVC membrane is placed? Is the intention to provide redundancy through the use of 2 separate membrane systems?
Given the folks you usually find on BU roofing crews, I’m not wild about putting a torch and a tank of propane in their hands on top of one of our client’s buildings, either; I prefer either hot or cold-applied plies. The Seamens Fibertite PVC membrane is a good product, but I don’t like to put down loose-laid single plies; get a leak and the water will run all over the place underneath it, making spotting the leak (after you’ve removed the ballast) very difficult. I’m also not sure about what could go on between the PVC membrane and the chemical constituents of the underlying plies and application materials.
Stick with all products from one sourse. By the way, if your project is in a coastal location with a Seagull population, the birds are intelligent enough to mistake light colored gravel (or rock ballast) for clams and drop them from high onto glass canopies to break the clams open. Only thing that broke was the top ply of the laminated glass panels.