# Failed Hot Air Welds in PVC Single-Ply Roofing



## boilerup73 (Apr 4, 2019)

In conducting an annual roof inspection on a PVC single-ply roofing recover installed back in April, 2016, a number of protective walkway pads made of the same PVC roofing material provided by the roofing Manufacturer, had begun to pull loose from the PVC membrane surface beneath in addition to many beginning to roll up on end. Unfortunately, after numerous phone calls and email correspondences to the roofing manufacturer regarding this matter, a year and a half later in 2018, I was assured by the manufacturer's rep that the open/loose protective walkway pads had since been addressed and corrected by one of their approved/certified roofing contractors. Fast forward to May 20, 2019 and it has since come to my attention during an annual roof inspection of this particular commercial property that the majority of protective walkway pads are once again open/loose along their edges (refer to photos) in which event the condition can only become progressively worse over time whereby the protective walk pads will become loose enough and eventually blow off the roof. This being the case, it seems logical that the initial hot air welds along the skirts of the walkway pads failed miserably to begin with in addition to any subsequent repairs allegedly performed by others resulting in a condition no better than that requiring repair. In contrast, I have another commercial property that has a TPO single-ply roofing system with TPO protective walkway pads installed back in 2014 whereby the pads are as well sealed today along their outer skirt as they were when they were first installed. BTW, this isn't to blame the PVC roofing material for this occurrence since the actual PVC roofing side lap seams are in overall good weather tight condition. All told, I am just curious as to why the PVC protective walk pads separated from the PVC roof surface to begin with. Obviously, the initial hot air weld failed. However, I am curious to learn whether this was due to a material defect in the PVC walkway pads, improper hot air welding, dirty/unclean mating surfaces, etc. and whether the proper resolve is to remove the existing PVC walk pads, clean the PVC roof surface beneath, and install/weld new PVC walkway pads or wash/clean the old ones to once again weld them to the PVC roof surface. What say you, who install single-ply PVC, TPO roofing systems for a living? Thank you all ahead of time.


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