Certified Polymer Thickness As a building owner, if a manufacturer sells you a 45 millimeter membrane, you assume there is that much “polymer” throughout. Not so. The polymer used in a roofing or waterproofing membrane is critical to the longevity, durability and weldability of the membrane. An increase in polymer can improve the long-term performance of the roof
According to ASTM guidelines, “nominal” polymer thickness can be up to 10% off in its advertised amount – and there’s no way for you to know. Lower than advertised polymer thickness can reduce a membrane’s puncture resistance and the overall performance of your roof or waterproofing system.
Click here to view a PDF of our Certified Polymer Thickness brochure
Manufacturer
A Advertised Thickness (MILS)
B Actual Measured Thickness (MILS)
C Difference A-B (MILS)
TPO F
45
45
0
TPO J
45
31
-14
TPO C
45
43
-2
PVC K2
45
43
-2
PVC K
36
33
-2
PVC N
50
46
-4
PVC M
50
44
-6
PVC V
50
40
-10
PVC M2
40
34
-6
PVC F
48
43
-5
PVC D
35
28
-7
Sarnafil S membrane
48
49
+1
Sarnafil G membrane
48
48
0
Source: Comparative Testing and Rating of Thirteen Thermoplastic Single Ply Membranes 1998 Study conducted by C.G. Cash of Simpson, Gumpertz and Heger
That’s why Sika Sarnafil introduced a Certified Polymer Thickness program. Our goal is to give the building owner, architect and specifier a guarantee that what they buy is what they get. It also helps heighten the awareness and importance of fair product comparisons. When multiple manufacturers are named in a specification, a certified polymer thickness requirement establishes a more uniform basis for comparison. This way, all specified products are required to meet the same polymer thickness criteria.
For your next project, specify a minimum polymer thickness – not a minimum sheet thickness. Also, consider requiring the manufacturers to submit a certificate of analysis. It’s really the only way you’ll be sure the product delivered meets your performance criteria.
