I have an exterior envelope consultant (who i have doubts about for a myriad of reasons) who sent over this comment, “We have seen examples of TPOs that have degraded after seven years”. We have TPO all over the Southwest that has lasted years. Have others had this type of negative experience with TPO?
Robin, I only spec typ TPO if forced to do so by Arch/Dev, I prefer products like Fibertite or SarnafilSika, at least for So FL Historically they do better than typ TPO’s.
Robin,
When TPO roofing first came out there were some failures. Before ASTM D6878 it was a race to the bottom to see who could manufacturer the cheapest membrane. That has changed now with the new standard. Though TPO roofing membranes are still the least expensive, they are used all over and provide good service.
I often am told to specify TPO on projects and have been seeing decent results. Like Jerome I prefer a good PVC like Sarnafil but I do what I’m told. When specifying TPO, go with manufacturers you know and trust.
As David points out, TPO roofs were initially the worst thing to happen to roofing since single-ply APP mod bits. While they have improved greatly by-and-large, please note that there are still some inherent concerns that need to be addressed in design because not all TPO’s are the same. While membranes no longer dissolve when exposed to rain, shrinkage is still considered to be an issue with some membranes. Unless the client specifically orders the AOR to use the cheapest thing on the market, please push back when told to use anything thinner than 60 mils. At least that way you can have some confidence that the reinforcing mesh is sufficiently protected by the top layer of membrane.
I agree completely with Ken!!
I realize this response may be late, but there have been instances in the southwest (generally south of Sacramento) where TPO roofs have been degrading more quickly due to UV exposure. One of the roofing companies set up some test panels and has been seeing faster degradation than expected. I still specify TPO, but I generally recommend that we ask for a 10-15 year warranty, and I specify only the well funded manufacturers with good track records. In addition, never specify anything less than 60 mils thick and go for 80 if you can. I’ve been following this for a few years now.