To which FM standard would you refer for seam performance and Single-Ply Roofing Systems?

• A. FM 1-60
• B. FM 1-40
• C. FM 1-35
• D. FM 1-29

Answer: (D)

Seam performance is the deciding factor for reliability in single-ply roofing systems, because the seams are where leaks most often start. The standard that directly addresses this topic for single-ply membranes is the one dedicated to single-ply systems. It sets the criteria and test methods for how seams should behave under real-world conditions—such as temperature changes, wind uplift, and movement of the roof deck—and it guides material selection and installation methods to ensure the seams will hold up over time.

The other FM standards listed cover different topics or roof types and don’t specifically target seam performance of single-ply membranes, so they aren’t the most appropriate reference when you’re focusing on seam integrity for single-ply systems.