While it’s easy to categorize a ‘bad’ vapor barrier, it’s harder to identify a good one quickly if you lack experience and training. However, knowing the difference between a good and bad vapor barrier is key to your home’s health, so it is best to contact a professional.
‘Bad’ Barriers
Arguably, there are only two ways in which a vapor barrier can be ‘bad’. Firstly, it can be damaged in some way, whether through accidental incidents or through inherent defects. Secondly, it can be unfit for its intended purposes. Under these circumstances, a vapor barrier can be classed as ‘bad’ for your property. However, there are many more cases in which a vapor barrier can be non-ideal.
Vapor barriers can be categorized by their width and grade. Barriers as thin as 6mm can be found, for example, but we would recommend that you never stray below 8mm in thickness. Thinner barriers are more prone to tearing and puncturing when put under pressure. Vapor barriers can be found in 3 grades, too, and while they each have their benefits, we would never recommend a grade 3 as these are porous and will let water through.
‘Good’ Barriers
Getting a ‘good’ vapor barrier means getting a barrier that is tough enough to stand up to the job that you have in mind for it. This means protecting your home passively, but also standing up to pressure and use when needed. This is why you should have thicker barriers, where possible, and if you intend to use your crawl space for storage, we recommend a 20mm reinforced barrier for optimal tear and puncture resistance.
As for grading, we would always recommend a grade 1 barrier for use in a Colorado crawl space. While grade 2 vapor barriers do an excellent job, they are semi-permeable and will not stand up to perimeter saturation. Grade 1 barriers, by contrast, are entirely waterproof and will not let moisture pass, whether in liquid or vapor form. This makes them the most reliable vapor barriers by far!