The seven crawl space problems we see most in the Upstate are a musty smell, soft or sagging floors, standing water, mold on the framing, fallen insulation, pests and high energy bills. Almost all of them trace back to one cause: moisture. That's why one fix, sealing and drying the crawl space, solves most of them at once.
1. A musty smell in the house
Why: Damp wood, mold and wet insulation under the floor. Crawl space air rises into the house.
Fix: Dry the crawl space with sealed vents, a liner and a dehumidifier.
2. Soft, bouncy or sagging floors
Why: Joists and subfloor that have absorbed moisture for years. Researchers at the USDA Forest Products
Laboratory note that wood will decay above 30% moisture content and will not decay below 20%.1
Fix: Stop the moisture first with encapsulation. Damaged
framing may need a carpenter. We'll tell you at inspection if we see it.
3. Standing water after rain
Why: Red clay holds water, and homes on slopes take runoff toward the foundation.
Fix: An interior French drain and sump pump, then a sealed liner.
4. Mold on the joists
Why: Humidity above 60%. The EPA recommends keeping indoor humidity below 60%, ideally
30–50%.2
Fix: Mold remediation plus moisture control. See
crawl space mold: signs and costs.
5. Insulation hanging down or on the ground
Why: Fiberglass batts soak up moisture, get heavy and fall.
Fix: Insulation removal, then new insulation or insulated
walls as part of a Gold or Sapphire encapsulation.
6. Termites, roaches and rodents
Why: Moisture and shelter. The National Pest Management Association says subterranean termites "are
attracted to moisture."3
Fix: Sealed vents and a lined floor take away the damp conditions pests want. Keep up regular termite
inspections with your pest company.
7. High heating and cooling bills
Why: Damp air is harder to heat and cool, and ducts in a humid crawl space lose efficiency.
Fix: In DOE-sponsored research, homes on closed crawl spaces saved on average 15% or more on annual
heating and cooling energy compared with vented ones.4 Results vary by home.
The common thread
Six of these seven start with moisture, and the seventh, high bills, gets worse because of it. Fixing them one at a time costs more than fixing the cause. Read the real cost of waiting, or book a free inspection to see which of these your crawl space has.