The number one area your crawl space is getting moisture from is the ground. When you look at dirt, you can see there is a certain level of water content in it. What happens, when you don’t have anything protecting that crawl space from the ground, is that the natural water in the dirt is going to evaporate up into the air of the crawl space. A crawl space vapor barrier stops this from happening. It acts like a rain jacket for your crawl space. In most South Eastern states like North Carolina and Tennessee, it is code to have a 6-mil vapor barrier completely covering the floor of the crawl space. Crawl Space Brothers installs from the code required 6-mil up to our fiber-reinforced 20-mil. Give us a call to receive a free inspection and vapor barrier quote!
Most state building codes in the Southeast require that the crawl space has a vapor barrier. In North Carolina and Tennessee, the minimum thickness is 6 mils. This standard 6 mil, although not the longest-term option available, is great for any crawl space, especially if the home is going to be listed for sale. These two states also require that the vapor barrier is run up to the walls, completely covering any open dirt areas of the crawl space floor. County building codes sometimes add on to the existing state code by requiring that all the vapor barrier seams be taped. This means that wherever the barrier overlaps, it must be sealed, usually by a commercial-grade 4-inch waterproof tape. Make sure to check with your local professionals to see what is required for your home.
“Is there a difference between a moisture barrier and a vapor barrier”? One of the questions homeowners frequently ask when doing research on what is required for their crawl space. The short answer is NO! Vapor barriers and moisture barriers both serve the same function; to stop water from evaporating out of the ground and into the crawl space. The only small difference is that the term “crawl space moisture barrier” can refer to a material outside of the polyethylene vapor barrier family. Moisture barriers can be woven black fabric tarps or sometimes even a cardboard-based product. We always recommend doing a vapor barrier since the material is polyethylene-based, it does not deteriorate or absorb water from the ground.
Finding the right crawl space vapor barrier installation crew can be difficult. Always make sure the installation company is knowledgeable of what is needed for your crawl space by asking a few questions.
Going through the questions above should help every homeowner make the right decision for their crawl space need. Another thing to keep in mind is that most of the larger companies only offer full-encapsulation, which sometimes cost prohibits homeowners from taking the first step in getting the crawl space up to code. Having a vapor barrier is always better than not having one!
The cost of a new vapor barrier can vary a good amount depending on several main factors. What type/quality of barrier is being used, does local code require the seams to be taped, what size is the crawl space, how accessible is the crawl space, and is there a debris cleanout required? Cost always depends on the answers to the above questions. Most vapor barrier installations are from $1,000 up to $5,000 (although sometimes our customers will receive other estimates for up to $15,000 on JUST a vapor barrier). STOP THE MADNESS!