5 Problems With Single-Ply Roofing Systems

TPO and EPDM single-ply membranes are among the most common commercial roofing systems installed today. They're cost-effective and perform well when new — but here are 5 problems building owners frequently encounter.

1. Seam Failure Is Inevitable

Every single-ply system relies on seams — heat-welded (TPO) or adhesive-bonded (EPDM). Daily thermal cycling gradually stresses these seams, and over 10–20 years, seam adhesion fails. Since seams are the #1 cause of commercial roof leaks, aging single-ply systems eventually leak at predictable locations.

2. No Insulation Value Added

Single-ply membranes provide essentially no insulation value (R-0 for the membrane itself). A building with inadequate roof insulation before TPO installation will have the same insulation problem after installation.

3. End-of-Warranty = Full Replacement

Unlike spray foam systems, single-ply warranties cannot be renewed with a simple recoat. At end of warranty, the system typically requires full tear-off and replacement — another $7–$12/sq ft investment.

4. Susceptible to Wind Uplift at Edges

Mechanically fastened single-ply systems have attachment points that create thermal bridging and potential wind uplift vulnerabilities at the fastener locations and perimeter edges.

5. Difficult to Seal Complex Penetrations

Every HVAC unit, pipe, and skylight penetration requires custom-fabricated boots and terminations — each a potential failure point. On roofs with many penetrations, the seam count multiplies accordingly.