Should I Remove Old Vapor Barrier?

If this is your line of thinking, you might be setting yourself up for unnecessary effort and expense in the future. The reason being that unfortunately, simply putting vapor barrier (crawl space plastic sheeting) down is not enough to solve all the issues that will ever arise in your crawl space.

Installation is one thing, but maintenance of the vapor barrier, and of the crawl space in general is the other important side of the equation, and it is often overlooked. Without putting any effort into maintaining your crawl space, you’re simply postponing the problem.

The problems may not come immediately, but they will still come. And once these problems have arisen it is often very costly to remedy them. Regular maintenance is low cost, and prevents expensive problems in the future.

But what kind of problems? Let’s talk about a few of the issues that could happen if you neglect your crawl space.

Crawl Space Problem #1: Mold

If the seal of your old vapor barrier is compromised, it lets large amounts of water vapor to enter your crawl space from the earth under your home. If this condition continues over a long period of time, soon the materials in your crawl space such as floor joists and fiberglass insulation start to absorb large amounts of moisture. And when mold spores are carried by the wind into your crawl space and land on a moist piece of wood or insulation, mold begins to grow.

But once mold has taken hold it can be very expensive to be rid of. It can cost thousands of dollars to remove mold from a crawl space and ensure that it does not return. However, if the mold caused any structural damage to the joists it might not be enough to simply remove the mold, but also to repair the damages. Why not give yourself peace of mind by taking measures to ensure that mold cannot grow in the first place?

Crawl Space Problem #2: Critters

With holes in your vapor barrier it can be easy for small ground dwelling critters such as ants, termites, mice, moles and crickets to enter your crawl space. Of course larger critters with claws and teeth are capable of ripping or tearing up through the vapor barrier, it is still a major deterrent and having an intact vapor barrier will turn most of them away.

But vapor barrier is only one line of defense. It doesn’t do much good to have vapor barrier if your crawl space vents are wide open providing entry points for all manner of varmints. Once critters check into a warm crawl space, they often don’t check out – preferring the shelter of the crawl space to the scary world outside. Crawl space critters can cause a lot of damage down there. Fiberglass insulation under your floor joists often becomes used as warm and fluffy nesting material for raising rats and mice.

To remedy this, we recommend not only replacing your vapor barrier if needed, but also to look into crawl space encapsulation. Our Hybrid Crawl Space Encapsulation system actually seals your crawl space off so that it is difficult for critters to even enter in the first place which helps protect your vapor barrier.

Crawl Space Problem #3: Energy Waste

While not directly a problem related to frayed vapor barrier itself, wasted energy is nonetheless a significant problem that can happen in any crawl space that is not encapsulated properly. One of the steps in our Hybrid Crawl Space Encapsulation System is to seal the air ducts in your crawl space HVAC system.

Did you know that on average about 25% of your conditioned air is lost in the crawl space through gaps in the ducting system? If your AC costs are $100 one month, that means that $25 of that $100 is from wasted air! Another way to look at it is that not only are you losing 25% of the air from your home, but that air gets replaced by (often dirty and dusty) air from your crawl space.

To remedy this and start saving your money and improving your indoor air quality, we recommend looking into air duct sealing. Air duct sealing is just one of the many steps included in our Hybrid Crawl Space Encapsulation System.

Crawl Space Problem #4: Cat-Urine Odors

So you just had some new vapor barrier installed and you're feeling very good about it. The guys that sold you the stuff told you that you were getting the best of the best: reinforced vapor barrier. But slowly over the coming months you cannot help but notice a strange yet familiar odor seemingly originating from your crawl space. You go down to investigate. But as soon as you open the crawl space door it hits you in the face like a mack truck, the smell of cat pee!

Why does your crawl space all of a sudden smell like cat pee you ask? Well, unless your running an underground cat-breeding operation in your crawl space, you can probably blame your new vapor barrier! We actually don't recommend this reinforced vapor barrier because most of it is made from sub-par materials and processes.

First water comes into contact with the threading holding the two plastic membranes together which wicks deep into the barrier and starts to rot the adhesive. This rotting adhesive is what causes the cat urine-like odor. So if you got suckered into covering your crawl space with some bad reinforced vapor barrier, yes we recommend replacing it quick! Give us a call and we'll help you out.

These are just a few of the many expensive issues that can arise if you neglect your crawl space. So back to the primary question at hand, should you replace your crawl space plastic (vapor barrier)? The answer is, it depends on the state of your vapor barrier.

If it has been over 10 years since you had the vapor barrier installed you should definitely inspect it for damage like fraying and tears. Even if it has only been a short time since you got the vapor barrier installed, it doesn’t hurt to get into your crawl space about once or twice a year and check out the state.

If there are only one or two minor tears, you should be able to repair it yourself with some seam tape. But if the damage is extensive, it would be best to replace the plastic and consider encapsulating your crawl space.

Simply ‘having vapor barrier’ is not a final solution. You should always consider encapsulating as well because encapsulating seals the crawl space and drastically reduces the number of pests that are able to enter and potentially start ripping your expensive crawl space plastic to shreds -- a favorite pastime of raccoons and badgers.

So hopefully this article has convinced you to at least stick your head into your crawl space and take a look at the condition of your crawl space plastic, or vapor barrier (whichever you want to call it). And if you’re too afraid to stick your head in – give us a call!
If you have questions about replacing your old crawl vapor barrier and want to speak with one of us – contact us through this form and we’ll be in touch.

Leave a Comment