Crawl Space Encapsulation in Sioux Falls, SD

Why Crawl Space Moisture Matters

About 50% of the air on the first floor of your home originated in the basement or crawl space. That means everything happening down there — humidity, mold, dust, radon, soil gases, pest droppings — gets pulled up through floor penetrations and HVAC returns into your living space. The "stack effect" makes this worse in the winter when warm rising air pulls cold, damp crawl space air up after it.

Encapsulation breaks this cycle.

Our Encapsulation System

1. Cleanout. We remove old loose insulation, debris, and any pest contamination.
2. Repairs. Failed sill plates, sagging joists, or compromised structural posts are addressed before sealing.
3. Vent sealing. Foundation vents are sealed permanently — modern building science has moved away from venting crawl spaces because it brings in humid summer air that condenses on cool surfaces and feeds mold.
4. 20-mil reinforced vapor barrier installed across the floor and up the walls, mechanically fastened and seam-taped. We use a true 20-mil polyethylene-reinforced membrane — not the 6-mil "visqueen" some installers cut corners with.
5. Insulation on the inside of the foundation walls (rigid foam or spray foam, depending on your specific situation).
6. Dehumidification. A self-draining commercial dehumidifier holds the space at 50-55% relative humidity year-round.
7. Drainage. If the crawl floods, we install an interior drainage and sump system before encapsulating.

Benefits Sioux Falls Homeowners Notice First

• Musty smell gone — usually within a week of completion.
• Floors feel warmer in the winter (especially over the encapsulated area).
• Lower humidity upstairs in the summer; HVAC works less hard.
• Energy bills typically drop 10-15% on average per the Department of Energy's field studies on encapsulated crawl spaces.
• Pest activity drops dramatically — they don't like the new environment.
• Mold-friendly conditions are eliminated, which is huge for anyone with allergies or asthma.

What Encapsulation Costs in Sioux Falls

• Standard encapsulation (clean crawl, no major repairs, ~1,500 sq ft): $7,500-$12,000.
• Encapsulation + interior drainage + sump: $10,000-$16,000.
• Encapsulation + structural repair: add $2,500-$8,000 depending on scope.

Free inspection, fixed-price written quote.

Should You Vent or Encapsulate?

Building codes have moved away from venting crawl spaces in mixed-humid climates like ours. Modern best practice — and what we install — is a fully sealed, conditioned, encapsulated crawl space. Older homes built with vented crawls almost always benefit from being sealed and encapsulated.

Frequently Asked Questions