The crawl space has an integral role towards a home’s overall value as well as the living space above. Most homeowners in Stuart Heights Chattanooga 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 Moisture Control In Stuart Heights 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.
Crawl Space Encapsulation Systems DIY
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.
Proper Crawl Space Ventilation Can Improve Living Space Air Quality Inside Your Home
A crawl space dig out is the process of turning your crawl space into a basement. This vastly increases storage space and can, in some cases, increase living space as well.
But, a crawl space dig out can be an enormous and daunting task. And, if done improperly, it can be dangerous. If you don't want to have a professional do it for you, please follow the steps below.
To get started, find place in the outside wall of your crawl space that you can safely enter the new basement with a temporary or permanent set of steps. Make sure the wall opening is big enough to handle at least a 36-inch door, preferably making the area for the steps at least 48-inches wide.
If your soil is sandy or gravel and or may be full of water at least part of the year do not consider this procedure, it is very dangerous and you may damage or lose your house.
Make sure that prior to digging the hole for the outside exit, please build a header of sufficient size to hold the floor of the home where you will be removing the old foundation.
You need to excavate to a depth that will accommodate a four-inch concrete slab and still have at least 7-foot, 6-inches of clearance under your floor joist. It is entirely possible that you will have 48 inches of soil to remove.
When digging out a crawl space, you can not excavate any closer than 24 inches away from the existing foundation.
You can remove the soil sufficiently to work along the wall without removing the entire area you wish to change.
When you get the soil out to a depth that you prefer, pour a footer that is eight inches thick and 16 inches wide. The footer should be below the bottom of the new slab so it is a good idea to dig the area for the footer below the level you remove for the floor area. This is a very important step in a crawl space dig out.
Then, when your block is level with bottom of the old foundation wall you need to pour a four-inch thick slab of concrete on top of the wall and over to the outside existing wall.
Prior to pouring your "Cap" you must fill between the block and soil that is under the old foundation with fill sand or "Pea-gravel." Assuming that you probably have some kind of support under the center section of the floor system, you will have to provide support for the beam that is presently supporting the floor while excavate for a new footer for a steel post that will hold the floor of your new space.
Make sure your footer for this part of the project is about eight inches thick & 24 inches square.
You will need to level the floor area for your new slab and install four inches of perforated plastic pipe draining to a sub pit with an automatic sub pump that dispenses the water to the outside at least five to ten feet away from the foundation of the home. I'd suggest using "Pea-gravel" for fill under the slab but you can you fill sand also.
Now, build your stairs to the outside in a similar fashion but you need to cover it with a steel "pre-fab" unit such as a "BILCO."
If you do this correctly and maintain it, it will last for many, many years. It is strongly suggested you get a professional to do this job or at least help with it because mistakes can be dangerous and very costly.
Crawl Space Masters Specializes In Crawl Space Encapsulation in Stuart Heights TN.