ASTM D751 Comparison

Breaking Strength - Grab Method (Modified) with Heat Welded Seams

The maximum force required to break a welded sample of the membrane when pulled in opposite directions.

This is done by cutting a 4 inch x 6 inch (10 cm. x 15 cm.) sample with a 1.5 inch (4 cm.) seam centered in the sample, clamping it in 1 inch (2.5 cm) jaws and pulling it to break. The results are reported in pounds-force (KiloNewtons force) to break.

*All results have been reported in the machine direction (MD) of the fabric.

Test Results

Fibertite®	36 mil	508 LBF (2.3 kN)
PVC #1	45 mil	382 LBF (1.7 kN)
CPA	40 mil	348 LBF (1.5 kN)
NBP	50 mil	330 LBF (1.5 kN)
TPO #1	45 mil	320 LBF (1.4 kN)
PVC #3	50 mil	298 LBF (1.3 kN)
PVC #2	48 mil	270 LBF (1.2 kN)
PVC #4	48 mil	250 LBF (1.1 kN)
TPO #2	48 mil	206 LBF (0.9 kN)

This test is significant to forecasting the overall performance of the field seams. The physical property relates to the ability of a roofing membrane to remain intact and watertight when exposed to the forces exerted on a roof system.

These forces are often caused by high winds, thermal and/or structural movement.

Test Results according to ASTM Standards as Performed and Reported by Structural Research, Inc.