The crawl space has an integral role towards a home’s overall value as well as the living space above. Most homeowners in Chattanooga Tennessee don’t think twice about their crawl space unless they have to make repairs to plumbing, heating ducts or house wiring. While often thought of as no more than a storage area, it also has a tremendous impact on the overall indoor air quality of the entire home.
The Best crawl space insulation In Chattanooga TN
By default, the air quality of a crawl space is typically poor. Mold, mildew, radon gas and poor energy efficiency all create several problems. The air that circulates within it eventually makes its way up through the living space. Scientific studies show that up to 50% of living space air originates from the lowest level of the home. With homeowners more concerned about their home’s indoor air quality, the encapsulating of crawl spaces has become a popular solution for such problems.
A damp crawl space creates a safe harbor for harmful molds, in addition to dust mites, termites and other bugs that can infest the home. The presence of excessive moisture will also create a serious problem with the probability for the wooden structure of a home to deteriorate. Crawl space vents pose a further problem. While believed to be a solution to moisture problems, they, unfortunately, make the problem worse. As it turns out, the vents allow cold air and moisture in, which rises into the living area and therefore decreases the heating efficiency of the entire home.
Another all-too-common problem associated with crawl spaces is radon gas. Though it cannot be seen, smelled or tasted, radon is a radioactive gas that can contribute to poor health, including cancer. Radon gas makes its way through the earth, into the crawl space and the home’s living space. According to the U.S.E.P.A., radon gas is the number one leading cause of lung cancer in non-smokers.
Ignoring these various conditions is not recommended for both long-term health and energy usage. Fully encapsulating a crawl space – by both sealing and insulating – is a fully efficient measure in addressing such problems. It makes sense to maintain and improve the lower level area in order to maximize healthy living conditions and home resale value.
While there are several systems for encapsulating, a zero perm liner system that also insulates and reflects heat provides the most benefits. With a proper floor and wall liner, the area will not only be well insulated but will seal out moisture, bug infestation, and radon gas. Other components to look for in a system include a radon gas-dispersing drain fabric, a radon gas ventilation pipe, and a ceiling heat shield.
A complete system with all of the above components will allow any soil gasses – including radon gas – that naturally occur under the liner system, to wick through the drain fabric and escape out through the ventilation pipe. While improved indoor air quality is the primary benefit of a sealed and insulated crawl space, the homeowner will also appreciate a bright, clean, and dry storage area; the ridding of musty smells; less energy usage; and tax credits. Contractors encapsulating crawl spaces will have more to offer to their clients when they can assure the peace of mind with improved indoor air quality.
What to Do About Basement Waterproofing Before It's Too Late
Installing a crawlspace vapor barrier is not rocket science. It is not physically difficult. Whether installing a quality vapor barrier in a vented crawlspace or doing a complete crawlspace encapsulation, it only takes a little time, a little patience and a willingness to crawl around on your hands and knees for a couple of days.
Where to Buy a Crawlspace Vapor Barrier
There are many places to purchase a crawlspace vapor barrier. An on-line search will provide contact information many retailers. And the products they offer vary from inexpensive clear plastic to woven and coated fabrics much like swimming pool liners. The inexpensive liners can also be purchased from many hardware stores and home centers.
What Vapor Barriers Are Available
The inexpensive vapor barriers will do the job but it's been our experience that they tear easily, don't stay in place, and become brittle and crack after four to five years. But they are inexpensive.
The alternative is to spend a couple times more initially and purchase a product with a twenty five year warranty. The reinforced or woven products require no more time to install than the inexpensive shorter-lived products.
The real question is whether an installer wants to spend a couple of days crawling around in a damp crawlspace every four or five years, or wants to spend a little more initially and have an installation that is maintenance-free and will last for decades. Personally, it makes more sense to me to do it right the first time and be done with it.
Installing the Vapor Barrier
Whether doing a full crawlspace encapsulation or simply installing a vapor barrier in a vented crawl space, the installation of all products have a lot in common.
First, the floor needs to be completely covered, with all seams overlapped 6" to 12" and sealed with tape. While duct tape is a wonderful product with countless uses, it does not do a good job sealing the seams of a vapor barrier. A quality, water-proof vinyl tape designed specifically for sealing the seams is recommended.
Wrapping the Crawlspace Piers
Second, the floor material needs to be sealed around all the foundation supports. Whether steel posts or concrete block piers, it is necessary to prevent the migration of water vapor from around the foundation supports. This is usually done by wrapping the piers - sealing the piers with the vapor barrier 6" to 12" up from the floor. This provides a sealed pier to which the floor material can be sealed to using seam tape.
Wrapping the piers can be a little problematic. No safe, nonflammable, nontoxic construction adhesive is effective with the available materials except for a newly developed, patented proprietary wall and pier liner. The vapor barrier is typically applied to the piers using a combination of tape, mastic, caulk, and mechanical fasteners. The mechanical fasteners require that holes be drilled into the piers using a masonry bit and hammer drill. This adds exponentially to the installation labor.
The patented wall and pier liner can be applied to most any surface using a low VOC and nontoxic construction adhesive. Being low VOC and nontoxic, it is nonflammable and safe to use in the confined area of a crawlspace. It can be safely installed in a fraction of the time. It is the only material of its kind and can be ordered from it manufacturer.
Sealing the Crawlspace Walls
Finally, regardless of whether you're installing a vapor barrier in a vented crawlspace or doing a full encapsulation, it is necessary to seal the floor material to the crawlspace walls. Most experts agree that this is a vital step for a well installed barrier or encapsulation.
If installing a vapor barrier, the floor material should be sealed to the wall 6" to 12" above the outside grade. Like wrapping the piers, most companies recommend the tape-caulk-mechanical fastener combination. The mechanical fasteners should be placed every two to three feet long the perimeter of the crawlspace. If taking this approach, be sure to use a respirator as concrete dust can cause severe respiratory problems.
If doing a full encapsulation, the entire wall, a minimum of three inches down from the sill plate to allow for a pest control inspection, should be sealed. Enough floor material can be purchased to extend up the walls or, the method we've found easiest, the wall is covered and sealed with a wall liner and the floor material is sealed to the wall liner using seam tape. Regardless of which method you use, the vapor barrier must be securely attached and sealed to the wall.
The manufacturer of the pier wrap also makes a patented wall liner that attaches to and seals the wall in one simple step. It reduces installation time by several hours. Like the pier wrap, it is available from the manufacturer.
Crawlspace Vapor Barrier Mythbusters
There are advantages and disadvantages in having a crawl space under your home. Advantages, perhaps, a slightly elevated home may be more attractive than a home on a slab. Plus, you can make repairs and modifications to plumbing, heating, and electrical services.
Disadvantages, a crawl space is an area that is never cleaned. Under the vapor barrier the humidity is always 100% so mold and bacteria are always present. Termiticides, other chemicals, even rodent droppings may be present, and odors and gases that emanate will migrate into the home's living space unless proper ventilation is installed. Whether on a slab or elevated, if radon is present, good ventilation is required.
There are several technologies on the market in regard to moisture control. One is encapsulation, sealing the crawlspace. Though this might lower humidity, it's costly and there is no dilution or replacement of stagnant, poor quality air. Again, if radon is present, ventilation is required.
Another technology is to install a dehumidifier in the crawl space. This can lower humidity, but again will not dilute or replace the stagnant air. Another point to think about is that the dehumidifier will be costly to operate. More importantly, using a dehumidifier requires you to close tightly the crawl space. Thus, the home's living space air quality is going to be lowered because the crawl space air is not diluted and replaced with fresh outdoor air.
Some systems use a dehumidifier control (dehumidistat) to operate a crawl space vent fan. This sounds like it's going in the right direction. However, the technology isn't quite right. Here's why. Suppose the outdoor air is getting worse (wetter). Though the dehumidistat control is in the crawl space, it will quickly recognize this wetter air condition and begin ventilation, even though ventilating is going to make crawl space wetter. Another problem with a dehumidistat control is that most of them are not made for the difficult environment of a crawl space, so their warranties are short, 30 days to 1 year maximum for the dehumidistat.
There is another system that uses special technology different from all the others mentioned above. This special technology makes a comparison of the actual moisture content of both the air inside the crawlspace and the outdoor air. The result is that it pauses and does not ventilate when bringing in outdoor air is going to make the space wetter. Then, as the outdoor air is getting drier and is able to improve the moisture and air quality in the crawlspace, then this ventilator moves a lot of air which dilutes and replaces stagnant air, ultimately improving your home's living space air quality.
This system, called the Smartvent, is made in the USA, is used from Florida to Alaska... San Diego to Nova Scotia.
This system is a proven system, and it is the only system to have undergone a year long test where crawl space humidity averaged 46%. Besides the unique technology this system employs, it also has the longest warranty of all ventilators, five years.
Crawl Space Masters Specializes In Crawl Space Encapsulation in Chattanooga TN.