Nashville Crawl Space Waterproofing

Crawl Spaces in Nashville  have been always around, but they became increasingly popular when homeowners started to recognize the improved convenience they have. Compared to the conventional floor setups and concrete floors, crawlspaces granted easy access to the plumbing setup and air ducts, and repairing them became effortless. Moreover, crawlspaces were also used as a storage facility. However, like any good thing in the world, crawlspaces also have its fair share of problems: trapped moisture, vermin, termites, and carpenter ants; invasion of wildlife and accumulation of foul gases to name a few.

mold in crawl space under house

Crawl Space Remediation Nashville

crawl space conversion

I’ve been doing  crawl space encapsulation in Nashville for more than two decades now. A good number of correspondences I have addressed were always concerning the foul smell and bad odors that are generated from crawlspaces. It’s imperative to recognize the root causes behind such foul odors and we need to work on strategies that will eliminate the root causes. Crawlspace encapsulation is relatively a new technique which will help you to protect your crawl space, and the health of your family. However, you need to know how to choose the right encapsulation system for your home.

By encapsulating your crawl space, you no longer have to worry about rodents or other wild animals invading your crawl space, moisture accumulation, termites and foul smell that was haunting you for long. A Do-It-Yourself encapsulation kit will undisputedly help you to protect your home from unwanted disasters.

Crawlspace Vapor Barrier Mythbusters

crawl space drainage

If you get three general contractors together and the topic of discussion turns crawlspaces and moisture control, you will probably hear six opinions. Even the experts seem to have different and often conflicting opinions about what tack is the best to take.

There has been much research on crawlspace encapsulation during the past decade. The US Environmental Protection Agency, the US Department of Energy, the ZEBRAlliance at Oak Ridge National Laboratories, and a non-profit research organization called Advanced Energy have all done excellent and groundbreaking research in the area of crawlspace encapsulation. Their research findings were instrumental in the last revision of the International Building Code. They all agree in a few, very important areas.

When considering your home, think of it as a single system. Your HVAC system, insulation, windows, attic, living space, and crawl space all work together. All of these building components need to be optimized and balanced to achieve maximum comfort, performance and energy efficiency. Your crawlspace is an important part of this system.

Your house is like a giant chimney. By natural convection, air is drawn in through crawlspace vents and air leaks. Because warm air rises, the outside air is drawn through the living space (along with mold spores, odors, and moisture) and exhausted through the attic. In the summer, your crawlspace is naturally cooler than the ambient outside temperature. So when the warm, humid outside air reaches the cooler crawlspace surface areas, the moisture condenses on framing, plumbing, wiring, insulation and especially HVAC ductwork and "sweats", just like an iced tea glass sweats on your kitchen table in the summer. In the southeast it is not unheard of for crawlspace humidity to approach 100% and actually rain inside the crawlspace.

The moisture in your crawlspace creates an ideal environment for wood destroying organisms, mold, and mildew. It can saturate and destroy the effectiveness of your insulation and promote wood rot. And because of the chimney effect, the humid crawlspace air, full of mold and mildew spores, eventually finds its way into your living space creating an unhealthy environment and causing your air conditioning to work overtime to dehumidify the air. Just a vapor barrier might help a bit, but most of the moisture is coming from outside, not your dirt, crawlspace floor.

So, the alternative to a vented crawlspace is an encapsulated (sealed) crawlspace. Crawlspace encapsulation involves sealing all outside vents, installing a high-performance vapor retarder on all exposed wall and floor surfaces at or below grade, insulating the walls and rim joist, and conditioning the air.

The prevailing research claims that by insulating the walls and rim joist, it is unnecessary to insulate the floor. However, if the existing floor insulation is in good condition, leave it in place. We generally recommend a rigid foam board insulation that is fire-retardant, low VOC, and offers an R-13 value or greater. It cuts easily and can be used for sealing existing crawlspace vents too. The sill plate should be caulked and paper-faced fiberglass insulation is used to insulate the rim joist.

The building codes in most areas require the air in an encapsulated crawlspace to be conditioned. That generally means adding a dehumidifier or using the existing HVAC system to condition the air. The EPA and the Department of Energy recommend using the existing HVAC system at a rate of one cubic foot per minute of conditioned air per fifty square feet of crawlspace area. A qualified HVAC contractor can add one or two 4" or 6" vents to a system for a nominal cost. The vents are usually equipped with a butterfly valve that can be adjusted to get the desired air flow.

We prefer using this method since the installation of the vents is generally less expensive than a crawlspace dehumidifier. And since running a dehumidifier is about the same as running a small refrigerator, the cost of conditioning the air with an HVAC system is generally less than running a dehumidifier. Remember that you're not trying to heat and cool your crawlspace; you're just adding a small amount of conditioned air. A relative humidity target of 60% or lower is a good place to start.

When comparing high performance vapor barriers, look at puncture and tear resistance. Other than being absolutely water tight, a high performance vapor barrier should also be flexible, fire resistant, low VOC, and lightweight. There is a world of difference between the 6 mil vapor barrier material sold in most hardware stores and a high performance specialty product. Most reputable suppliers will provide samples.

In addition to dramatically increasing indoor air quality and protecting the structure of your home, several research studies from Advanced Energy indicate that crawlspace encapsulation can actually lower energy usage. These studies were done in several parts of the country with varying climates.

Crawl Space Insulation and Its Benefits

crawl space drainage

I've been in the crawl space business for 15 years and I've seen almost every system you could imagine - from spray foams to concrete to thin plastic sheets. Some are better than others, but the only real way to encapsulate the area beneath your home is to install a liner with zero permeability.

What is Zero Perm?

Zero Perm means just that absolutely no water, moisture, radon gas or odors will penetrate through it. Tests have to show 0.000 penetration of Hydrogen gas (the smallest gas molecule) through the membrane. The whole idea of spending the money to encapsulate the crawl space or basement is to STOP water, moisture, radon gas and any unpleasant odors. Liners that are 6, 12 and 20mil thick are NOT Zero Perm and will still let in harmful gasses as well as letting in moisture that will only continue to feed the mold and bugs that try to get in your home.

What Else Should I Look for in a Liner?

If you are going to spend the time & money to install a crawl space liner look for more benefits as well as zero permeability. Look for liners that are

- Energy Star Rated to get a 30% Tax Credit back on your purchase
- R Value of 5 to add insulation & increase your heating/ cooling efficiency
- Reflectivity value of 97% to prevent radiant heat loss
- Class A / Class 1 fire rating

Homeowners all over are finding that improving the homes they have is more cost effective than buying new. Some homeowners like the fact that they can save money by doing the work themselves and some still prefer to have someone else do the installation. Either way, using a Zero Perm, Energy Star Rated encapsulation system is a great way to pre-finish a basement or any area underneath your home.

If you crawl space is in need of repair, Crawl Space Masters can help!