What makes a vapor barrier "high performance"?
Posted by Nana Hinsley on Tue, Jan 10, 2012 @ 04:58 PM
If you are doing your homework regarding vapor barriers, you have probably come across descriptions for "vapor barriers" and "high performance vapor barriers." What makes a vapor barrier "high performance"?
There are several factors that contribute to the high performance credential. A high performance vapor barrier will always be made from 100% virgin resin. This means there is no re-ground plastic or other contaminants in the liner. 100% virgin liners hold up much better than liners you may find in a home improvement store that says,"6 mil vapor barrier". There is confusion in the market in that people think that is a liner is a certain mil thickness, then it will perform well as a vapor barrier. Nothing is farther from the truth. If you don't want to replace your vapor barrier a few years down the road, research and make sure you are getting the best liner to meet your special circumstances.
The next factor that makes a vapor barrier "high performance" is the fact that the liner/barrier is specifically manufactured to be a high performance vapor barrier. This engineered plastic vapor barrier was constructed to meet certain criteria. Under consideration is what the surface will be like where the liner will be placed. Is the area rocky or made up of a granular fill? There are test methods that are performed on liners to insure they will hold up when they are in contact with granular fill. This test is called, ASTM E1745. This test also places the vapor barrier in simulated situations to mimic service conditions.
High performance vapor barriers are tested for their water vapor permeance or water vapor transfer (WVT), tensile strength, and puncture resistance. They are also must be resistant to decay. Click here if you want to learn more about the strict guidelines that high performance vapor barriers must pass.
Some other high performance vapor barriers also called, vapor retarders are engineered to block deadly soil borne gases like radon. These vapor barriers are made with such a tight cell structure that they are 50 percent less permeable than typical polyethylene vapor retarders.
To read about the various high performance vapor barrier, please click here.