kurt Posted December 16, 2010 Report Posted December 16, 2010 Here's a little pictorial of a TPO install. I'm owner's rep on this gig. The start is tear off everything there to expose the sheathing, repair whatever is screwed up, and cover it with 1" polyiso, then a 1/2" expanded perlite Fesco board, then the TPO. Anyone wonders, this is a wonderful system; the hot air welders are a miracle. No flame, quiet, and relatively easy to operate. While not always liking what I've seen with TPO, this is the 60 mil. All of what I've seen is 40 mil; the 40 mil seems to bag, and it just seems "thin". There's also an 80 mil, which I'll be seeing in 3 months on another job. It was all shot on the Pentax W90 [utube] " type="application/x-shockwave-flash" wmode="transparent" width="425" height="344"> The following shows some basics: This is the field seamer; I didn't get any video of this, but you can figure it out from the video; it's a hot air welder, and those two rollers pinch and seal the seam. Click to Enlarge 42.81 KB This is a basic layout @ the base: Click to Enlarge 23.78 KB All seams are tested with this pick shortly after running the seam; it's on the back end of the roller too: Click to Enlarge 16.77 KB Here's the basic reinforcement patches: Click to Enlarge 16.44 KB The membrane is extended through the scupper hole: Click to Enlarge 15.63 KB This metal has TPO bonded to the bottom, and the steel on top is welded/soldered to the metal gutter box (in this case, it's going to be copper). You can see the white layer on the "left" edge (opposite side from the label). I'll be showing the copper when it goes in. Click to Enlarge 35.21 KB
Marc Posted December 16, 2010 Report Posted December 16, 2010 How cold a day was it when this was done? Marc
Phillip Posted December 16, 2010 Report Posted December 16, 2010 The hot air welder are nice and so is the seamer. I used both of them when I used to install trocal roof and have done 2 TPO roof. I still have my roller and pick to check the seams. Kurt where they fastening down with screws and washers in the seams or gluing it down?
kurt Posted December 16, 2010 Author Report Posted December 16, 2010 It was a glue down, and the fesco board was held in place with screws and 2" washer heads. Marc, it was really cold; about 20degF. This was an experiment; I'm trying to get facile with using the camera for video and stills in sequence.
randynavarro Posted December 17, 2010 Report Posted December 17, 2010 So the hot air welder melts the two layers of TPO together, thus the real definition of "welding", right?
kurt Posted December 17, 2010 Author Report Posted December 17, 2010 Yup. It's amazingly cool how the air welder works.
Jim Katen Posted December 17, 2010 Report Posted December 17, 2010 Why did they choose TPO over PVC? - Jim Katen, Oregon
Marc Posted December 17, 2010 Report Posted December 17, 2010 Why did they choose TPO over PVC? - Jim Katen, Oregon Isn't PVC a thermoplastic? Marc
kurt Posted December 17, 2010 Author Report Posted December 17, 2010 Why did they choose TPO over PVC? - Jim Katen, Oregon Mostly my recommendation which was based on my knowledge of the installer. I've finally found a roofing contractor that goes to school and gets the certs from all the major mfg's. The original "dissing" of TPO by the PVC mfg's. is fading AFAIC, as installers are stepping up and mfg's. are refining material and method......TPO is really good stuff. Marc, yes, PVC is a thermoplastic polymer. PVC is vinyl based, TPO (thermoplastic polyolefin) is olefin based. Olefins are odorless, unlike PVC. Polyolefins are the largest class of polymers, and are the most widely used as they are not as expensive as Polyvinyl's. Polyvinyl's also have phthalate plasticizers; that's the stuff that leaches out of plastic and into our bodies. Polyolefins are not as prone to leaching, which is probably why they don't stink like PVC. I have no idea whatsoever what all this really means. I just read it on the mfg. websites.
randynavarro Posted December 17, 2010 Report Posted December 17, 2010 I've never seen a heat welder before. Now I've seen two in one week. That's the exact same tool they used to seam the marmoleum floor I just had put in my bathroom. I guess they're pretty expensive.
Tom Raymond Posted December 20, 2010 Report Posted December 20, 2010 Polyvinyl's also have phthalate plasticizers; that's the stuff that leaches out of plastic and into our bodies. They also contain lead. You know, cause it's a safer plasticizer.
BornaRoofer Posted May 17, 2011 Report Posted May 17, 2011 Just a few comments. You should never glue tpo unless its 40 deg and rising. And you shouldnt glue anything to fesco it will never stay stuck. Fesco is for hot asphalt only. Insulation is to be fastend with 3" plates and tpo is to be fastend with 2" barbed plates. And he was holding that leister welder backwards in the seam as he welded. I hope it holds up for you.
kurt Posted May 17, 2011 Author Report Posted May 17, 2011 Well, that would surprise the mfg. rep who blessed the installation, and the installer that has his training cert from the mfg. It'll hold up.
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