THURSDAY, FEBRUARY 7, 2013

 

Crawlspace Moisture Control Brentwood, TN    Reeves Crawl Space Services

615-290-2228     www.ReevesCrawlSpace.com

 

If you get three general contractors together and the topic of discussion turns crawlspaces and moisture control, you will probably hear six opinions. Folks, seem to have different and often conflicting opinions about what tack is the best to take. The idea of crawlspace encapsulation (sealing) has been around for a while now. Reeves Crawl Space Services revolutionized encapsulation in the Tennessee and has become the local authority on the subject.

 

There have been many studies on crawlspace encapsulation during the past number of years. The US Department of Energy 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 concur 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 venting system. 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 roof. In the summer, your crawlspace is naturally cooler than the higher outside temperature. So when the warm, humid outside air reaches the cooler crawlspace areas, the moisture condenses on framing, plumbing, wiring, insulation and especially HVAC ductwork and “sweats”, just like an ice water sweats on your kitchen table in the summer. In the southeast it is not unheard of for crawlspace humidity to approach 90% 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 venting 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. In as much as a vapor barrier can help, it won’t stop the moisture coming in from outside.

 

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 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.

 

             Reeves Crawl Space Services prefers 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.

 

Got questions about crawl space moisture in Tennessee?  Call us at 615-290-2228 or visit us on the web at www.ReevesCrawlSpace.com

 

 

 

Shaun Reeves ACE

Reeves Pest Control

www.ReevesCrawlSpace.com

www.ReevesPestControl.com

Keeping Tennessee Pest Free!

615-290-2228     931-223-8327

 

Shaun Reeves is the first certified entomologist in Williamson County, TN.  Reeves Pest Control is the premiere crawl space encapsulation company in Middle Tennessee.