Crawlspace Insulation
Crawlspaces can cause multiple issues in the main living areas of your home. Oftentimes, these areas have insulation that has been neglected for too long. When not well-sealed, insulated and protected from moisture, crawlspaces can make your home feel cold, drafty and musty-smelling.
Crawlspace Insulation Improves Moisture Control
As part of our top-to-bottom inspection included in WHI's home performance audit, we take a look at the condition and insulation of your home's crawlspace. Insulating a crawlspace is often an "out of sight, out of mind" project, but most people find their homes are more energy efficient and comfortable when the crawlspace is encapsulated and insulated.
What Kind of Insulation?
Since many crawlspaces have dirt floors, WHI usually recommends a 6 mil layer of plastic as a moisture barrier. Dow Thermax™ rigid insulation is a good choice because of its moisture barrier design. Another option once the moisture barrier is laid down is Icynene spray foam insulation, which creates an excellent thermal boundary that can stop home air loss through the floors. The combination of plastic sheeting and insulation is often referred to as "crawlspace encapsulation."
How Much is Enough Crawlspace Insulation?
Because crawlspaces are not heated or cooled by the home's HVAC systems, they require slightly less insulation: R-10 to R-13 is required to meet federal efficiency codes for new construction, and is a good guideline for proactive insulation upgrade results in our area.
Where is Insulation Installed in the Crawlspace?
The walls of the foundation, the box sills (where the floor support joists meet the top of the foundation walls), and between the joists on the underside of the floor above are all areas that should be insulated for improved home comfort. If there is ductwork located in the crawlspace that connects to the furnace or central air, the WHI insulation specialist may recommend wrapping it with fiberglass insulation to prevent heat loss.
