Crawl spaces are prone to moisture issues, temperature fluctuations, and air leaks. Insulating this area helps to create a more stable and comfortable living environment by preventing cold floors, reducing energy loss, and mitigating moisture-related problems such as mold and mildew.
Properly insulating your crawl space is crucial for maintaining your home's energy efficiency, preventing moisture problems, and improving indoor air quality. Here’s a detailed guide to help you insulate your crawl space effectively.
How To Insulate A Crawl Space
Equipment Checklist
Materials:
- SmartSHIELD 20MM, SmartSHIELD 10MM, SmartSHIELD 5MM, SmartSHIELD 1/4 Inch. Choose based on your R-value target.
- SmartTAPE reflective foil tape: For sealing seams.
- Double-sided tape: For attaching SmartSHIELD to concrete walls.
- Super metal sealant: For bonding SmartSHIELD to surfaces where drilling isn't possible.
Tools:
- Utility knife
- Staple gun or screw gun
- Measuring tape
Before You Start
- Check for standing water or active leaks. Fix any drainage or moisture issues first.
- Seal gaps and air leaks around vents, pipes, and the rim joist with spray foam or caulk.
- Make sure the crawl space has proper ventilation per local building code.
Installing on Crawl Space Ceiling (3 methods)
Choose one method, or combine A and B for maximum performance.
Method A: Under the Floor Joists
Recommended SmartSHIELD: 3mm, 5mm, 10mm or 20mm.
- Roll SmartSHIELD across the underside of the floor joists.
- Staple or screw it directly to the bottom edge of each joist.
- Seal seams with SmartTAPE.
Method B: Between the Floor Joists
Recommended SmartSHIELD: 16-inch or 24-inch roll to match joist spacing.
- Cut SmartSHIELD to fit between joists.
- Staple or screw the edges to the sides of the joists.
- Leave at least 1 inch of air gap below the floorboards.
- Seal seams with SmartTAPE.
Method C: Combine A and B
For maximum thermal performance, install Method B between the joists first, then add Method A under the joists for a second reflective layer. Seal all seams with SmartTAPE.
Installing Crawlspace Wall Insulation
Crawl space walls are typically concrete. There are two ways to attach a SmartSHIELD.
Option 1: Stud or Furring (Best Performance)
- Install wood studs or furring strips against the concrete wall.
- Staple or screw SmartSHIELD to the studs or furring, leaving at least 1 inch of air gap.
- Seal seams with SmartTAPE.
Option 2: Direct to Concrete
- Apply liquid nail adhesive in a continuous bead along the wall.
- Press SmartSHIELD against the wall, securing with double-sided tape and the sealant.
- Seal seams with SmartTAPE.
Installing Crawlspace Floor Insulation
The floor layer acts as a vapor barrier between the dirt and the rest of the crawl space.
Recommended Insulation: SmartSHIELD 5mm - white, SmartSHIELD 10mm - white.
- Roll SmartSHIELD across the floor with the white side down (against the dirt) and the foil side up.
- Overlap each row by at least 3 inches.
- Extend the layer up the walls by 6 inches where possible.
- Seal all seams and overlaps with SmartTAPE.
Benefits of SmartSHIELD Reflective Insulation In Crawlspace
- Keep your floors noticeably warmer
- Reduce air infiltration and drafts
- Save energy and money by keeping heat and air conditioning inside
- Minimize problems with condensation, wood rot, mold and mildew
- Provide waterproofing
- Seal entry paths against termites
- Radon resistance
R-value test parameters
SmartSHIELD resists mold, mildew, and fungus growth, and it holds its R-value even when wet. That matters in a crawl space, where moisture is constant and most fiber-based insulation breaks down over time.
Crawl spaces can also pull radon gas up from the soil into the home. Indoor air pressure is usually lower than the pressure in the surrounding soil, so radon naturally flows toward the lower-pressure space. Warm interior air rising through the house adds to the effect, creating a slight suction that draws more gas upward through the crawl space. A continuous vapor barrier across the crawl space floor helps cut that path off.
A poorly insulated crawl space can be a major source of a home's total heat loss. SmartSHIELD is built to block downward radiant heat transfer specifically, which is exactly what a crawl space needs. Heat radiating down from the living floor reflects back into the home instead of escaping into the cold space below. The result is warmer floors, lower bills, and steadier room temperatures. SmartSHIELD does all of this while serving as the vapor and radon barrier in the same install.
Need Help Choosing?
Browse the SmartSHIELD collection or call us at (786) 202-0704 for sizing and contractor pricing.
