Roof Seams Coming Apart on Flat Roof: What to Do?

Failing seams are the #1 cause of commercial roof leaks — and they're inevitable on aging TPO and EPDM systems. Here's what to do when you notice seams coming apart.

Why Seams Fail

Daily thermal cycling causes commercial roofing membranes to expand and contract. Over years, this stress gradually weakens heat-welded or adhesive seam bonds. Seams that were perfectly sound when installed eventually lose adhesion — creating microscopic openings that allow water infiltration.

Immediate Action: Stop Active Leaks

If seams are actively leaking, apply compatible lap sealant or caulk as an emergency measure to stop water infiltration until a proper repair or restoration can be planned. This buys time but isn't a permanent solution.

Option 1: Seam Repairs

For isolated failed seams on an otherwise sound membrane, targeted seam repairs make sense. A qualified contractor cleans the failed seam area, applies compatible primer, and either re-welds (TPO) or re-bonds with EPDM primer and adhesive. This is cost-effective for truly isolated failures.

Option 2: Silicone Coating Restoration

When seam failures are widespread across an aging membrane, individual repairs become impractical. A silicone coating restoration seals every seam on the entire roof simultaneously under a continuous new membrane — solving the problem permanently with a new 10–20-year warranty. This is the most cost-effective solution for roofs with systemic seam deterioration.