EPDM roofing is a popular synthetic rubber membrane known for its durability and flexibility, often used on flat or low-slope roofs. Blistering on EPDM surfaces happens when moisture or air gets trapped between the membrane and the roof deck or the adhesive layer. This can occur due to improper installation, such as poor adhesive application or failure to thoroughly dry the surface before installation, or from trapped moisture within the roof deck itself. Over time, blistering can cause small, bubble-like formations on the membrane, which may eventually lead to cracks or punctures if left unchecked. Simple diagnostics include visually inspecting the roof for raised bubbles or soft spots by gently pressing on suspect areas—though avoid pressing too hard to prevent damage. Safe DIY checks are mostly visual: look for any peeling edges, cracking, or areas where the membrane seems to be lifting.
If you notice significant blistering or if the roof is aging and showing other signs of wear, it’s wise to call a professional roofer who specializes in EPDM systems. They can determine if a repair, patching, or more extensive replacement might be needed to preserve your roof’s integrity. When speaking with a contractor, consider asking: “How do you handle blister-related repairs for EPDM, and what guarantees do you offer on your work?” Also, inquire about their approach to preparing the surface and ensuring the adhesive bond is secure to avoid future blisters. Knowing their process can help you avoid issues that might void your warranty or lead to ongoing problems.