Stevens Roofing Systems
Stevens EP™-Fleece Physical Properties

Physical Property Test Method Typical Values 45 mil*(1.14 mm) Typical Values 60 mil*(1.52 mm)
Thickness ASTM D-751 45 mil membrane plus fleece 60 mil membrane plus fleece
Breaking Strength

ASTM D-751

340 lbf. (1.5 kN)

400 lbf. (1.8 kN)

Tear Strength

ASTM D-751

(Procedure B, 8"x8" sample)

135 lbf.(.60 kN)

120 lbf.(.53 kN)

Dimensional Stability (% change max.)

ASTM D-6878 (white: 6hrs. @ 158°F/70°C)

+ 0.3% + 0.2%

Hydrostatic Resistance

ASTM D-751Method A

500 psi (3.5 MPa)

540 psi (3.7 MPa)

Ozone Resistance**

ASTM D-1149

(70 hrs. @ 100°F/37.8°C)

Pass

Pass

Low Temp. Bend ASTM D-2136 @ -40oF/-40oC

Pass

Pass

Weather Resistance

Xenon Arc, ASTM D-6878 G-155;

5040 kJ/m² 0.35w/m² @340nm

No cracks, Loss of breaking strength or tear strength

No cracks, Loss of breaking strength or tear strength

EMMAQUA (Concentrated Natural Sunlight (ASTM G-90) 167 359 kJ/m² total UV radiant exposure

Pass

Pass

Puncture Resistance

FTM 101B (Method 2031)

450 lbf. (2.0 kN)

500 lbf. (2.2 kN)

Water Vapor Transmission ASTM E-96 (Procedure B Condition BW @ 72°F/22.2°C

0.035 Perms

0.035 Perms

Elongation (%) Ultimate**

ASTM D-412 (Die C)

700%

700%

Brittleness

ASTM D-2137 @ -49°F/-45°C

Pass

Pass

Water Absorption (max. % weight change)**

ASTM D-6878 D-471, (158°F/70°C for 7 days) Testing only one side section

+ 3 + 3
Heat Aging

ASTM D-6878 D-573 (28 days @ 240°F/115°C)

Break: 250 lbf. (1.1 kN) Break: 290 lbf. (1.29 kN)
Solar Reflectance (initial) ASTM E-903 >70% >70%
Thermal Emittance ASTM E-408 >0.93 >0.93
Thickness (nominal) per ASTM D-751 test method.
**Test performed on non-reinforced Stevens EP™ membrane