The crawl space has an integral role towards a home’s overall value as well as the living space above. Most homeowners in Murfreesboro 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 waterproofing crawl space In Murfreesboro 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.
Addressing Moisture, Mold and Radon Gas in Basements and Crawl Spaces With Application of a Deep-Pen
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.
A Closed, Sealed Crawlspace - What a Really Bad Idea
Outlined below are the most common 4 methods I have seen used in installing a vapor barrier. If you talk to different builders, you usually will end up with many different methods of installing a vapor barrier in a crawlspace. Here are the most common:
1. Pea Gravel on top of plastic vapor barrier - This has to be the all time dumbest thing I have ever seen, and yet it is probably one of the most common. I have had builders tell me that the plastic on the ground KEEPS ground water and moisture from coming up from the ground. Now if there is no moisture or water in the soil, this might be possible; but if that was the case there would be no need for the barrier in the first place. So here is the basic idea - ground floor (bottom) - plastic (middle) - 4" pea gravel fill (top). Once the crawl foundation is built, builders install a 4 - 6 mil plastic on the ground and dump about 4" - 6" of pea gravel on top of the plastic. Eventually, what always happens is that water comes in from the walls and the ground floor and ends up on top of the plastic. So what you end up with is a swimming pool liner that holds water in the gravel for prolonged periods of time. Nearly all the water and moisture in the gravel back fill has to evaporate into the structure. Another example of building practices and science turning a blind eye to crawlspaces for decades.
2. Vapor barrier on top of ground floor - By far the most common practice for installing a vapor barrier. A 6 mil polyethylene vapor barrier is placed over any ground floor. Here is the idea - ground floor (bottom) - plastic (top). The ground floor could be river rock, pea gravel, dirt floor, sand, etc. The seams are typically overlapped 6" - 12" and almost never taped. While this will temporarily stop some moisture evaporation, it does not seal out moisture from the internal perimeter wall where most water penetration occurs. Also moisture can come up from the seams, and the plastic is not durable enough to crawl on. It nearly always ends up with many punctures and holes in it.
3. Vapor barrier on bottom of floor joists - This is rarely seen, and usually only home owners attempt this. This is probably the method that accounts for more wood rot than any other method. If you are even thinking of doing this, quit thinking and call a professional to fix your crawlspace. Most crawlspaces are vented and the cooler surfaces such as duct work, pipes, and the floor will condensate in the summer. The plastic will trap the condensation up against the floor structure and mold and wood rot will occur. Good intentions do not always produce good results.
4. Vapor barrier fastened to sill plate - There is a new industry in crawlspace repair that encapsulates crawl spaces. The process of encapsulation is to install a heavy think plastic liner on the floor and up the foundation walls. The plastic liner is fastened and sealed to the foundation wall and all the overlapped seams are taped. Every potential gap or seam in the liner is meticulously sealed to prevent any moisture from evaporating. Then the vents are sealed in the encapsulation system to prevent hot humid air from entering in the summer. There is another system being sold and installed out there being represented as an encapsulation system, but is far from it.
This "other" system is a 6 mil plastic that is ran up the foundation walls and stapled to the sill plate. None of the overlapped seams are taped. It is basically a glorified vapor barrier on top of the ground floor being ran up the walls and stapled to the wood. They seal the vents without properly sealing the moisture from the ground floor or foundation walls. The problem with fastening plastic to the sill plate is that moisture will "wick" up the foundation wall, and moisture will absorb into the sill plate and floor joists. They are giving free access to all the moisture under the liner to rot the sill plates and floor joists. Not to mention that all the moisture will evaporate up through all of the seams that aren't taped and the plastic liner is only 6 mil and eventually will puncture and tear. Be very careful in the contractor you choose to properly encapsulate your crawlspace.
Crawl Space Masters Specializes In Crawl Space Encapsulation in Murfreesboro TN.