Building Code Says 6 Mil Is Fine. That Doesn't Mean It's Good

0:00So let's start with something that most contractors use as their excuse for installing 6mm plastic building code. According to the International Residential Building Code, the minimum requirement for a vapor barrier and a vented crawl space is 6mm polyethylene plastic. That's it, 6mm. Now here's what contractors want to. Minimum means minimum. It's the absolute bare minimum that you can get away with and still meet code. It doesn't mean it's good. It doesn't mean it's going to last. It doesn't mean it's in your best interest as a homeowner. Think about it this way. Building code also says you can build a house with 2x4 studs, but most builders who believe in quality use 2x6s. Because it provides space for better insulation for improved comfort and sound proofing. It's stronger and according to the internet, R21 insulation in a 2x6 versus R13 insulation in a 2x4 may reduce utility bills by up to 57%. It's just a better house. Same thing with vapor

1:00barriers. The building code for vapor barriers was written decades ago and it hasn't kept up with what we know about moisture control, building science, and long-term durability. The code is really designed to keep you from building something dangerous. It's not designed to give you the best possible solution. And I can tell you from 20 years of experience in thousands of crawl spaces across seven states, 6mm plastic is not a long-term solution. It's barely a short-term solution. Now let's talk about the number one problem with 6mm plastic. It's too thin, period. 6mm means 6,000ths of an inch. To put that in perspective, that's about the thickness of a cheap trash bag. Actually, it's thinner than most contractor grade trash bags. You can easily tear it with your bare hands. No tools, no sharp objects, just your hands. Now, do you really want something this fragile as the only barrier between your home and ground moisture? Here's what happens in the real world. Your crawl space isn't some sealed-off area that nobody ever goes into, although you may not

2:05personally go in there. You've got the HVAC contractors going down there to service your heating and cooling system. You've got plumbers going down there to fix leaks. You've got electricians running wires. You've got pest control technicians. You've got home inspectors during real estate transactions. Every single time someone or something crawls across that 6mm plastic, they're creating stress points. They're creating tears. They're creating punctures. And once you get a little tear, it just keeps getting bigger and bigger. I've seen 6mm vapor barriers that look perfect when they were installed. And 6 months later, they've got tears. One year later, they look like swish cheese. And two years later, they're completely destroyed. And this isn't an isolated problem. This is the norm. This is what happens with 6mm plastic and moderate to high traffic crawl spaces, which, by the way, is pretty much every crawl space. In fact, I'd estimate that 70 to 80% of the 6mm vapor

3:05barriers I inspect are damaged within the first two years. That's not a long-term solution. That's a temporary band-aid that's costing you money. And I'm Michael Church with Crawl Space Ninja, and I hope you make it a happy and blessed day. And we'll see you later.