Why You Need a Crawlspace Vapor Barrier
Save Money on Heating and Cooling
Moisture finding its way in from a crawl space can make your home feel hot and humid. With a vapor barrier in place, you can run the A/C less and save on cooling costs.
Protect Your Home From Water Damage
Most people think about flooded basements and burst pipes when they think of water damage, but consistent high humidity can be just as bad for the wood and masonry beneath your house.
Prevent Mold and Mildew
Mold spores are dangerous to human health. Inhaling them can cause everything from allergic reactions to long-term disease, and the worst of the worst carry deadly toxins. Mold loves dark and damp places, so the best way to prevent mold from growing in your crawlspace and spreading to the living areas is to keep it dry with a vapor barrier.
Is your vapor barrier installed properly?
Vapor barriers are more than just a sheet of plastic tucked somewhere under the floorboards. To actually keep a home dry and insulated, vapor barriers need to be properly installed. A poorly installed vapor barrier can do more damage to your home than none at all!
This guide will show you what to look for to see if your current vapor barrier can pass muster.
Three Ways NOT to Install a Vapor Barrier
With Gravel On Top
A lot of contractors have been putting down a layer of thick plastic vapor barrier, then layering gravel on top, This isn’t a vapor barrier–it’s a swimming pool!
It seems like these contractors are thinking that they will stop groundwater from rising up into a basement. They’re wrong. All this kind of “vapor barrier” can do is trap rainwater. It won’t be able to absorb into the ground because there is a thick plastic sheet in the way, and the gravel will act like a perfect aquifer. Water will have one place to go: up into your foundation.
While often well-intentioned, installing a vapor barrier incorrectly like this is worse than not having a vapor barrier at all.
Stapled to a Ceiling
When homeowners try to install a vapor barrier in a crawlspace, it is quite common for them to staple sheets of thick plastic to the ceiling of their crawlspace as a “vapor barrier”.
This kind of vapor barrier doesn’t do a thing to stop moisture from getting into your home. It does guarantee wood rot beneath the plastic sheet. Just like with the gravel-over-plastic installation, a vapor barrier plastic stapled to the ceiling will actually trap moisture, not block it.
This will be even worse if the barrier covers any pipes or ducts. Cool metal surfaces like air ducts collect condensation during the summer.
Normally this evaporates without anyone noticing, and no harm was done. But with a plastic sheet covering the duct, the condensation will end up soaking into your floor joists. It’s a recipe for mold.
Wrapped Around the Walls
Many contractors will try to sell homeowners something that looks like a full encapsulation system by wrapping vapor barrier sheets around the walls of a crawl space and stapling them to the wood sill plate.
There are a couple of huge problems with this kind of system.
Staples punched through the plastic act like little steel wicks. Any moisture that gets between the foundation walls and the plastic will wick right into the wood house frame. This not only defeats the purpose of a vapor barrier but introduces serious risks of wood rot, mold, and structural damage.
When contractors do these kinds of simple wraps, they almost never take the time to tape the seams where sheets overlap. Moisture can easily wick through these gaps.
At the end of the day, this kind of installation only looks like a vapor barrier. In practice, it won’t come close to giving your home the protection of a crawlspace vapor barrier.
The Right Way to Install a Crawlspace Vapor Barrier
The correct way to install a vapor barrier in a crawlspace is surprisingly simple. Sheets of 6 mil vapor barrier should be used to cover the floor area, overlapped by 12 inches. No gravel coatings, no stapling things to the ceiling, and no gaps–just a clean, professional installation.
Dry Basement Solutions: Contractors You Can Trust
If your crawlspace or basement has problems with dampness or mold, call the experts at Dry Basement Solutions for a consultation. With over 25 years of experience in the remediation industry, the family owned and operated team is ready to tackle mold and basement water damage needs.
Visit their website or call 201-258-4540 for a consultation.