PVC Love with working photos now

I have some love for PVC. I crawled this on my hands and knees to find all the tiny splits and tear-outs at overdriven/overwelded seam plates.

Has since been overlayed with TPO. I'll be back. Sooner than later I think.

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/PVC1.jpg[/IMG]

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/PVC2.jpg[/IMG]>>>

I believe that the JM sheet of that era was being made by CGT, a poor sheet to start with. Making it black is just a huge mistake. I'm not surprised to see this at all.>>>

Vaa Fakaosifolau Said: So what are you saying? the plates were driven too far and then when the seams were welded together (over the plates) the membrane dipped down under tension, then later with the heat and cold and ensewing movent of the whole roof it cracked there?

the cracks seem to be on the underlying piece (could be an optical illusion)

The shatters and cracks are primarily at hand welds with few/no plates near them. Mostly end laps and skylight flashings. Just my theory, but I think the black tint ruined the blend of the membrane and made it brittle where even the slightest re-heat was applied like heating the edge sealant and skylight corner welds.

The seam plate tear-outs are a different breed of cat. The pressure roller of a Varimat follows the plane of the deck and if the plate is driven too deep, you end up with a weld that goes too far in and sometimes goes past the seam plate. This is where the positive air pressure inside the building lifted the sheet and tore/delaminated the back of the membrane up to the point of being even with the back edge of the rest of the seam weld, sometimes taking very small bits of the top of the membrane with it, through the weave. SOB leaks to find because they're such tiny tear-outs and this roof had long stretches where *every* seam plate was too deep.>>>

more

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/more1.jpg[/IMG]

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/more2.jpg[/IMG]

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/more3.jpg[/IMG]

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/more4.jpg[/IMG]

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It's JM UltraGuard. May be specifically colored for the customer who used to have an "..as long as it's black" policy. Interestingly, no branding on any boots or corners on this one, I got the Mfg. info after finding a serial/lot number on the backside of some loose wall flash. Same customer has fairly fresh (~4 years old) white UltraGuard PVC on a store a bit south of this one that looks fine.

This ~8 year old black one had a heavy chlorine smell to the backside. Rigid to the shatter point when cold, very flexible when warmed. Building has a lot of positive air pressure that "pillowed" the membrane much like a kid's "bounce house" when warm.

Brown crap must be a cut edge sealant? In the 600 squares of it, almost all of the 120+ half moon cracks were at hand welds. The seam plate tear outs were at over-driven plates and spots where it looked to me like the Varimat stalled.

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/seam1.jpg[/IMG]

[IMG]http://i80.photobucket.com/albums/j175/Roberts406/seam2.jpg[/IMG]>>>

I don't think I've ever seen a PVC that color. At least not with that particular thread weave. What is it?>>>

Water will find the holes eventually>>>