Sump pumps and crawl space drainage
Clay holds onto water. When it collects under a house, a sump, a drain line and some outside fixes get it moving again.
Crawl space drainage gets standing water out from under your house and keeps it from coming back. For Rock Hill and York County homes that collect water after storms, contractors combine outside work, like gutters, downspout extensions and grading, with inside work, like a perimeter drain line feeding a sump pit and pump.
Signs of a drainage problem
- Puddles or soupy clay under the house after rain
- Water on top of the plastic ground cover
- Water stains on the brick foundation or piers
- Rusty nails, straps or duct hangers
- Wood rot concentrated along one side of the house
Why water collects here
Many York County soils have dense clay subsoils, and the county's soil survey describes Iredell soils, for example, with a plastic clay subsoil. Clay like that lets heavy rain run off rather than soak in. If the yard slopes toward the house, or downspouts empty next to the foundation, the crawl space becomes the low point.
Common fixes
- Gutters and downspouts: cleaning them and extending downspouts away from the house
- Grading: building up soil so it slopes away from the foundation
- Exterior drains: a swale or French drain to intercept water
- Interior drain line: perforated pipe in a trench around the inside of the foundation
- Sump pit and pump: collecting water at the low point and pumping it out
The CL-100 connection
South Carolina's CL-100 rules treat standing water in the crawl space or around the foundation as excessive moisture, and they list a sump and drain system as one correction for poor drainage. If a report flagged standing water, this is often where the fix starts.
What affects the cost?
- Length of drain line and amount of trenching
- Sump basin and pump type, backup pump or alarm
- Where the discharge can go
- Outside grading and gutter work
- Electrical work for the pump
The contractor sets the price after seeing the site.
Common questions
Does standing water in a crawl space affect a CL-100?
Yes. South Carolina's rules treat standing water in the crawl space or around the foundation as an excessive moisture condition.
Do I need a sump pump if I fix my gutters?
Maybe not. If the water comes from roof runoff, gutters and downspout extensions may solve it. Groundwater or surface water from a slope usually needs a drain and sump.
Should drainage come before sealing the crawl space?
Yes. Sealing a crawl space that collects water traps the water under the liner.
Where you can get this done
Related services
- Crawl space sealing and encapsulation
- Vapor barrier replacement
- Crawl space dehumidifiers
- Rotted sill and joist repair
South Carolina licensing, the CL-100 moisture rules and York County soils are covered in the York County crawl space guide.
Wet clay under the house, a musty smell or a soft spot in the floor?
Give us a call and we'll connect you with an independent crawl space contractor working in Rock Hill and the rest of York County.