TPO roofing, or Thermoplastic Olefin, is a popular single-ply roofing membrane known for its durability and energy efficiency, but it can sometimes develop blistering. Blisters form when moisture or air gets trapped beneath the membrane during or after installation. This might happen if the roof deck was wet when the TPO was applied, or if improper adhesion or seam sealing occurred. Prolonged sun exposure heats the trapped moisture, causing the membrane to bubble or blister. Over time, these blisters can compromise the roof’s protective layer, increasing the risk of leaks or material failure. Diagnosing blistering yourself involves a careful visual inspection for raised spots, soft areas, or cracking on the membrane. It's generally safe to walk the roof with soft-soled shoes while checking for irregularities, but avoid poking or pressing too hard to prevent damaging the membrane.
If blisters are detected, it's important to evaluate their size and frequency to decide on the next steps. Small, isolated blisters might be repairable with patches if caught early, but widespread blistering or ruptured blisters usually require professional evaluation. It’s wise to call a roofer when blisters are large, numerous, or accompanied by wrinkles or seam separation. When consulting a contractor, ask whether the blistering might be due to improper installation and if the roofing warranty covers repairs or replacement. Also, inquire about the roofing system’s ventilation status, as poor ventilation can exacerbate moisture issues that lead to blisters. A knowledgeable roofer will recommend fixes that protect your roof’s integrity and maintain warranty compliance.