When It Comes to Insulation, Don’t Forget the Basement and Crawlspace

While it’s natural to look toward the attic or inside interior wall spaces when thinking about upgrading insulation, two areas beneath your living spaces deserve attention as well. Uninsulated basements and crawl spaces can serve as reservoirs of dank, cold air in winter and moisture-laden warmth in summer. The unconditioned environment in these zones promotes the growth of mold and other air contaminants that may infiltrate your home from below.

Basements and crawl spaces require different insulating techniques than living spaces and attics. Here are some guidelines for each zone:

Basements

• Insulating basement walls in any climate zone north of zone 3, including Delaware, will prove to be cost-effective by reducing utility costs and improving air quality.

• Basement walls in existing homes may be insulated from the interior side. Interior insulation will reduce interior space in the basement by a few inches.

• Install rigid foam board insulation in contact with the concrete basement wall, secured with adhesive or special fasteners. As an alternative to foam board, closed-cell spray polyurethane foam can be applied to the basement wall.

• Many building codes require a layer of gypsum sheetrock to protect foam installed on walls.

Crawl spaces

• Unventilated crawlspaces provide the best option as long as moisture control techniques are functional.

• Seal then insulate foundation walls, not the underside of the floor. This keeps plumbing pipes and HVAC ducts inside the thermal envelope and reduces energy loss.

• Install rigid foam board insulation on the foundation walls, secured with appropriate adhesive or fasteners. As an alternative to foam board, closed-cell spray polyurethane foam can be applied to the basement wall.

• Remove rocks and other debris from the dirt floor of the crawl space and layout a poly vapor barrier. Seal any seams in the barrier with compatible tape or mastic sealant.

• Install a forced-air register in the crawl space for a totally conditioned zone.

Sobieski Services installs insulation to ensure energy efficiency and preserve healthy indoor air quality.

Our goal is to help educate our customers in Delaware, Pennsylvania, Maryland and New Jersey about energy and home comfort issues (specific to HVAC & plumbing systems).

Image Credit: Deannster