Drainage & sump pumps in Charleston, SC
If water stands under your home after heavy rain, sealing the space isn't enough on its own. Interior drains and a sump pump collect water and move it out before the liner goes down.
What it costs
| Item | Published range | Source |
|---|---|---|
| Interior crawl space drain (French or perimeter), incl. pump | $800–$3,000 | HomeGuide, How Much Does Crawl Space Encapsulation Cost? (Jan 14, 2026) |
| Interior French drain, Charleston installer | $55 per linear ft | Coastal Crawlspaces (Charleston installer), published price list |
| Submerged sump pump (equipment) | $100–$400 | Angi, How Much Does Crawl Space Encapsulation Cost? (updated Oct 28, 2026) |
| Foundation waterproofing | $1,500–$15,000 (avg $4,600) | Angi, How Much Does Crawl Space Encapsulation Cost? (updated Oct 28, 2026) |
Ask about battery backup for the pump, since storms that bring water can also cut power.
Drainage & sump pumps FAQ
Why does my crawl space flood when it rains?
Common causes include grading that slopes toward the house, gutters dumping water at the foundation, and high groundwater. A pro should look at the outside drainage before selling you interior systems.
Do sump pumps need maintenance?
Yes. Angi suggests budgeting $500–$800 every five to ten years to keep drainage systems working (Angi, How Much Does Crawl Space Encapsulation Cost? (updated Oct 28, 2026)).
Where we can match you
Drainage & sump pumps requests are accepted across the Charleston area:
Downtown CharlestonWest AshleyJames IslandJohns IslandMount PleasantDaniel IslandNorth CharlestonSummervilleGoose CreekHanahanLadsonMoncks CornerIsle of PalmsFolly BeachKiawah IslandSullivan's Island
Related services
Crawl space encapsulationSeal the crawl space with a heavy liner, closed vents and controlled humidity.Vapor barrier installationReplace torn or thin plastic with a sealed ground barrier.Crawl space repairSagging floors, rotted joists, beams and sill plates.Crawl space dehumidifiersA sized dehumidifier to keep humidity in check year-round.Crawl space insulationWall or subfloor insulation that tolerates moisture.Crawl space mold remediationClean and treat mold before sealing the space.
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