Why has puncture resistance information changed on Perminator from the 2004 data sheet to current? Why does the 10 mil now have a higher puncture resistance than the 15 mil?
The data sheet that we have from 2004 is the original formulation of Permintor that far exceeds the requirements of ASTM E1745, Class A, the industry standard for plastic products used for underslab protection. There are also guides from ACI for concrete slab construction that makes reference to underslab vapor retarders and in some there are references within these documents for these products needing to have a perm rating of 0.01 perms. Back in 2012/2013, one of our competitors went to market stating that we did not meet this ACI recommendation as our material as our Perminator 15 mil had a permeance of 0.012 perms. As ridiculous as this sounds, and although we far exceed the industry standard, this did make some headway in the industry.
As a result, we decided to reformulate our Perminator products with new resin technology which allowed us to manufacture these products with a lower vapor permeance, which is reflected on the current technical data sheets that we produce. With these sorts of resin chemistries, producing a material with a lower vapor permeance does sacrifice the puncture resistance of the material. Basically, as the vapor permeance is lowered, so is the puncture resistance. As test results show, our current Perminator formulation still far exceeds the requirements set forth in ASTM E1745 for both permeance and puncture resistance, but does also meet the recommendations set forth in ACI 301.1R and ACI 302.2R. It is very important to not just rely on one of the performance characteristics of these materials, but all of them, which is something lacking within the ACI guidelines.
At the same time, for those individuals that did not require a material that was 0.01 perms and wanted a material far exceeding the industry standard, ASTM E1745, we decided to manufacture a material with these new resins, based on a high puncture resistance. This product is Perminator HP, which designates high puncture. It has always been our stance that puncture resistance is an extremely important function of an underslab vapor retarder.
When it comes to the difference in puncture resistance between the 10 mil and 15 mil products, the 10 mil product does have a better puncture resistance. The reasoning for this comes down to the ability of the product to “absorb” the weight better than the 15 mil, this being a result of the new resin chemistries that are available. The test method that is used is ASTM D1709 where varying weights are dropped from a height onto unsupported material, and it is when the weight goes through the material that dictates the puncture resistance. The 10 mil product also does have a lower tensile strength.
To support all of our published documentation, we do have third-party independent testing for all of these materials. In addition, a white paper is available regarding underslab vapor retarders and the whole relationship between permeance and puncture.