Depending on the nature of your building, it is also common that roof penetration items, such as HVAC units, vent pipes, electrical lines, etc., will be removed, replaced, and added. When these activities take place, holes are left behind that need to be repaired or re-flashed depending on the scenario.
When any of the above happens, the ability to make a proper long-term repair or new flashing to the roof membrane is critical. Furthermore, the original type of roof membrane that is specified and installed will determine the ability to perform a long-term repair as some roof membranes are much more difficult (and in some cases almost seemingly impossible) to repair than others. The reasons for the various repair limitations of the different roof membranes are numerous. There are however a few fundamental facts, such as surface oxidation or weathering surface degradation, that help explain the limitations.
Surface oxidation is akin to rust forming on steel whereas weathering surface degradation is a breakdown of the polymers on the surface. In either case, the surface to be repaired is no longer the original virgin material that was installed, and thus requires different processes and great care needs to be exercised to bond the repair material to the weathered surface. The bottom line is that you should be considering a roof membrane’s long-term repairability when selecting a roof system.
It is important to note that the repair process should be as identical to the original installation process as possible. Weathered roof materials require a lot of preparation to repair as repair materials can’t be bonded with just any surface. Using primers and scrubbing are typically necessary to make the surface bondable. If your roofing system is experiencing surface oxidation, buffing will often be required before repairs will be able to be made to remove the hard brittle surfaces.
Do you have any other questions you ask about life-time repairability of a roofing system before selecting/specifying a system? Tell us about it in the comments.