A.Roofer Joseph Bublick responds: In most cases, bubbles in EPDM roofing are just a cosmetic problem, as long as they aren’t growing. Usually, bubbles are not associated with leaks.
The most common cause of bubbles is the application of rubber to the deck or insulation board too soon, before the adhesive is dry enough. In some cases, a contributing factor can be high pressure in the roof system. If this is the problem, the solution is to install pressure-relief vents. Pressure-relief vents, which are one-way air vents...
to read the full article.