Roof Reinforcing Membrane

Reference # 5






PolyCore™ stitch bonded 100% polyester reinforcing membrane makes every repair stronger. The precisely spaced warp in the material provides integrated channels for liquid rubber to flow through, interlocking and further increasing dimensional integrity. PolyCore II™, with its flatter profile, permits complete encapsulation with less coating.

This reinforcing fabric is the premier membrane for adding strength to critical roof areas and repairs.

  • Exceptional multi-directional strength
  • Superior elongation properties
  • Adds strength to critical roof areas where repairs are made


4″ PolyCore™ is used for seams. 
6″ PolyCore™ is used for flashing. 
40″ rolls of PolyCore™ are used to efficiently cap larger sections, including entire roofs.




PolyCore II™


2lb./100 ft2

<2lb. 100 ft2

Tensile strength (min.)

55 lb.

75 lb.

Elongation (min.)



Mullin Burst

175 lb.

105 lb.

Trapezoid Tear

16 lb.

13 lb.

Roll Sizes

4” x 300’
6” x 300’
40” x 324’*

42” x 300’**

*Yields 10.8 squares after 4″ overlap
** Yields 9 squares after 6″ overlap


Q: What products is PolyCore™ compatible with?
A: PolyCore™ can be used together with Polyprene® or Seam/RivetGuard™ cements, or Topps Seal® coatings for larger sectional areas.

Q: Why would I need reinforcing membrane for my roof repair?

A: Even the highest quality coatings and seam sealers can only work across a certain width gap. They need solid material to hold onto with no gap more than 1/16”. PolyCore™ creates the needed material reinforcement for sealers to adhere to and close the gaps in lager seams.

Q: What size rolls does PolyCore™ come in?
A: You can purchase PolyCore™ in rolls of 4” x 300’, 6” x 300’, or 40” x 324’. And you can buy PolyCore II™ in rolls of 42” x 300’.