Crawl space drainage and sump pumps
Water standing on red clay under a house doesn't go away on its own. Here's how crawl space drainage is handled in the Upstate.
A wet crawl space feeds humidity into the house, soaks insulation, and keeps sill plates and piers damp. With around 50 inches of rain in a typical Spartanburg year and summer thunderstorms that drop a lot at once, getting water away from the foundation is often the first fix.
Why does clay make it worse?
The Pacolet and Cecil soils common in the Piedmont have red clay subsoils, and USDA soil descriptions give the clay layers slower permeability than the sandy loam on top. Rain can soak the surface quickly, then move sideways along the slower clay, sometimes straight toward the foundation. Once water gets into a crawl space with a clay floor, it can sit in low spots for a long time.
Start outside
- Gutters and downspouts. Keep them clear and extend downspouts well away from the house.
- Grading. Soil should fall away from the foundation. Settled backfill and mulched beds often create a trough.
- Hillside lots. On sloped Upstate lots, a swale or French drain uphill of the house can intercept water before it reaches the wall.
Then inside, if needed
When outside fixes don't stop it, an interior drain can. Perforated pipe in a trench along the inside of the foundation carries water to a sump basin, and a pump sends it outside. The vapor barrier or encapsulation liner goes over the system.
Questions about a sump
- Where does it discharge, and will that water come back toward the house or a neighbor?
- Is the basin lidded and sealed under the liner?
- Is there a high-water alarm or a battery backup for storm outages?
- How can I tell the pump is working?
Warning signs
- Puddles or wet clay under the house a day or two after rain
- Water marks or a white crust on block walls and piers
- A liner holding water on top
- Washed-out soil near downspouts
Near a creek or river?
The county's comprehensive plan describes narrow floodplains along the Pacolet, Tyger and Enoree rivers and their tributaries that take on water during heavy rain. A crawl space drain is for routine rain and groundwater, not floodwater. Check the FEMA flood map and talk to your insurance agent about flood risk.
Pricing is set by the crawl space company after someone has been under the house, measured it and seen what's wrong. We don't quote prices, and a figure given over the phone before an inspection is a guess at best.
Where we connect you with help
Common questions
Does every crawl space need a sump pump?
No. Only crawl spaces that keep collecting water after gutters, downspouts and grading are fixed. A company can tell you after seeing it, ideally after a good rain.
Can a sump pump stop creek flooding?
No. It handles everyday rain and groundwater, not floodwater rising across a property.
Related services
More background: Spartanburg crawl space guide.
Musty smell, sweating ducts or a floor that's started to dip?
Call the number above and a local crawl space company will help you figure out what's happening under the house.