Stevens Roofing Systems

Stevens EP™ Roofing Membrane

The World's First Reinforced TPO Roofing Membrane
Stevens EP™ brand of TPO is the world's first reinforced TPO (thermoplastic polyolefin) based roofing membrane. It is formulated from a proprietary compound of ethylene propylene rubber and polypropylene. Stevens EP™ membranes exceed the ASTM D-6878-03 specification for TPO roofing. They are environmentally friendly roofing materials from cradle to grave that provide outstanding weatherability, fire and chemical resistance. The seams and details of a Stevens EP™ roof are hot-air welded to create a bond stronger than the material itself.

Applications, Width and Thickness
Stevens EP™ is ideally suited for virtually all commercial, industrial and institutional applications, both for new construction and re-roofing. The material is available in nominal 45 and 60 mil thickness (1.14 mm and 1.52 mm) and comes in standard 100-foot length rolls. For surpassed puncture resistance and durability, Stevens also offers Stevens EP™-XL, an 80 mil (2 mm) thick material.

Stevens EP™ is available in widths ranging from 38.25" to 151" (.97m to 3.8m) and lengths of 75' to 300' (23m to 91m) to best fit the design criteria and code requirements of your roof. Many Dow Roofing Systems membranes can be produced in custom lengths (100' minimum, 30m) to eliminate seams and speed the installation process.

Attachment Options
Stevens EP™ membranes can be installed using several methods, including:

  • Mechanically Attached
  • Fully Adhered
  • Stevens GardenTop™ vegetated roof system
  • Stone Ballasted
  • Paver Ballasted
  • Vented Roofing System (VRS)

Choice of Colors
Stevens EP™ is available in a choice of nine aesthetically pleasing colors including:

  • Energy Efficient White*
  • Light Slate Gray
  • Pewter
  • Buckskin
  • Desert Brown
  • Patina
  • Dark Ivy Green
  • Neon Blue
  • Terra Cotta

All Stevens EP™ reinforced, colored membranes are available in 60 mil (1.52mm) thickness. Additionally, unreinforced 55 mil (2.17mm) material is available to harmonize with any color option. Pre-molded corners (inside/outside), pipe boots and vent gloves are also available in Energy Efficient White and Light Slate Gray.

* White Stevens EP™ membranes exceed the EPA Energy Star Roof Products Program requirements, (initial solar reflectance of 86% aged 85%) are California Title 24 compliant and may qualify for points in the U.S. Green Building Council LEED Program.

ISO Certification
In addition, all Stevens EP™ membranes are manufactured in an ISO 9001 certified facility.

Substrate Compatibility
Stevens EP™ membranes are suitable for direct contact over:

  • EPDM
  • CPE
  • CSPE
  • PVC
  • NBP
  • EIP
  • Neoprene
  • Aged Asphalt BUR
  • Aged Modified Bitumen

Model Building Codes

Fire and Wind Resistance
Stevens EP™ membranes have achieved UL Class A fire resistance classifications (UL 790) over selected polyisocyanurate, gypsum and wood fiber insulation and recover boards boards, and unlimited slope over Gypsum. Consult the current UL Roofing Materials & Systems Directory for complete details and listings.

Mechanically attached Stevens EP™ has achieved Factory Mutual Windstorm Classification Ratings of 1-60 up to 1-195.

Fully adhered Stevens EP™ can achieve 1-270 and 1-315 Windstorm Classification under specific conditions. Consult the current FM Approval Guide for complete details.

Stevens EP™ has numerous NOAs granted by Miami-Dade for a wide range of deck types and constructions.

  • Steel
  • Concrete
  • Wood
  • Lightweight Concrete
  • Cementitious Woodfiber
  • Gypsum
  • Recover Assem.

Warranty Options
Dow Roofing Systems offers warranties on successfully completed roofs installed by a Stevens Authorized Applicator. These warranties range in scope from coverage of the materials only to that of the entire system assembly for a time of 5 years up to, for some systems, 20 years.

TPO Membrane Choices
Depending on your application, Dow Roofing Systems has a TPO membrane for you. As a leading global manufacturer of TPO, Dow Roofing Systems has developed several TPO membranes for specific applications. Besides our standard TPO membranes, we also offer Stevens EP™-XL (80mil Thickness) and Stevens EP™-Fleece.