In this month’s edition we will describe the application of perimeter flashing at both high and low concrete parapet walls. As we have noted several times in this section, proper flashing details are critical to the success of the roof system (no matter what type of membrane system is applied) because approximately 75 percent of all roof leaks are reported at flashings and penetrations.
There are some flashing application methods that are standard and are required for all membrane systems. For instance, the flashing material should always be fully adhered to the substrate even on loose-laid and mechanically attached single ply systems. The flashing material should be applied to the required height on the substrate and out onto the roof membrane a minimum of four (4) to six (6) inches depending on the membrane manufacturers specific requirements.