EPDM Seams and Flashings – What’s Changed?
EPDM has always been known as one of the most durable roofing products available. Its high UV resistance and ability to stand up to weather over time has made it a very popular flat roofing product, decade after decade. Its ability to resist ponding water on roofs has also made it very popular as a man-made pond liner, among its many uses. However, EPDM has always had one big weakness: seams and flashings. Alternative single-ply roof systems, like TPO and PVC, can be heat welded. If completed correctly by a knowledgeable crew, a heat weld is the strongest bond available. It essentially welds the flashings and seams together with the base PVC or TPO membrane. With EPDM, heat welding isn’t possible, so the seams are instead bonded together with adhesives. In the early days of EPDM, seams and flashings were only expected to last 10 to 15 years. The reason was the technology they had at the time, which was a product called splicing cement. On most early EPDM roof systems, the seams were glued together using this method. Some manufacturers used caulking products to hold off water penetrating the seams, which could help buy some time. However, after a period of time, the result would always be the same – open seams and flashings. The cure to this problem was an expensive one: re-do […]
Roof Proposals – What to Keep an Eye Out For
Making sense of roofing proposals from different contractors offering varying solutions can be very daunting. Just understanding the myriad of solutions can be difficult enough without adding in products, terminology, etc. What makes it extraordinarily difficult, in my opinion, is when proposals are vague. In flat commercial roofing, there are a few key points to keep an eye out for in a quality proposal. They are: Tear Off or Go Over: If there are two or more roofs, or if the underlying insulation is wet, a tear off is generally required. If one roof is in place and only a few areas are wet, then the wet areas can be replaced on a limited basis. However, in flat commercial roofing, there is a big cost difference between removing the existing roof system and going over it. Therefore, it is very important to know what solution your contractor is proposing. Insulation Thickness and “R” value: Typically, in a go-over application, a minimum of 1” polyisocyanurate insulation or ½” HD polyisocyanurate insulation is used as a separation between the old roof system and the new roof system. However, if a full tear off is being completed, building code typically requires that the insulation be brought back to code. In 2020, this could mean installing 4.5” to 5.2” of insulation, depending on what building code calls for in […]