Crawlspace Encapsulation is ideal for air quality and comfort
Many homes in the Atlanta area are built over crawlspaces with poor insulation and poor moisture management in place.
Building science studies have shown that traditionally vented crawlspaces are often problematic in the Southeastern climate. Humid warm outside air is drawn into the cooler crawlspace particularly in the hot summer months. This increase in relative humidity can cause mold and other biological growth which can create a negative impact to air quality in the home – particularly when the HVAC and ductwork system are located in the crawlspace.
These are common problems in vented crawlspaces in the north Georgia climate:
Poor air quality
The damp environment in the crawlspace is often a breeding ground for mold and other growth that can negatively impact indoor air quality which can cause health problems. Crawlspaces communicate with the living space by allowing air from beneath your house into your conditioned living space through the various penetrations along your subfloor and through the exterior wall cavities. Insufficiently sealed HVAC ductwork located in crawlspaces can also draw crawlspace air into the HVAC system and distribute it inside your home.
Insect and critters are well-suited to living in the dark, temperate climate under your home. All too often these pests can make it into your living space from below.
Structural and mechanical damage
Buckled floors, rusting pipes and ductwork, and rotting of structural woodwork are all commonly seen, and largely due to the high humidity present for prolonged periods in the Southeastern climate.
What is ‘Crawlspace Encapsulation’?
An excellent solution for many vented crawlspaces is to encapsulate the crawlspace. What is ‘encapsulation’?
Encapsulation simply means the sealing up of your crawlspace from outside air and humidity. This entails installing a sturdy, reinforced vapor barrier along the entire floor of the crawlspace sealed along all seams and at least 6″ up all piers and foundation walls for complete coverage. This seals off the earthen floor which prevents ground moisture from entering the air. Closed cell sprayfoam is then applied along the foundation walls and piers and along the top of the rim joist to seal off the crawlspace from outside air. To circulate and avoid stagnant air in an encapsulated crawl, a small return and supply line is then run into the crawlspace from your HVAC air handler. This has the added bonus of warming the floors in the cold winter months. Alternatively, if your duct system is not easily accessible from underneath the house, you can install a dehumidifier.