Crawl space drainage and sump pumps
When rain hits shallow limestone, it has to go somewhere. Too often that's the crawl space under a Rutherford County home.
Crawl space drainage keeps water from pooling under your house. For Murfreesboro and Rutherford County homes that get wet after storms, contractors combine outside fixes like gutters and grading with inside fixes like a perimeter drain and a sump pump that sends the water out and away.
Signs your crawl space has a water problem
- Standing water, mud or wet soil under the house after rain
- Water on top of the plastic ground cover
- A water line or staining on the foundation walls or piers
- Rust on metal straps, nails or ductwork
- Sill plates or joists that are soft near one wall
Why water ends up here
Much of the county sits on soluble limestone with only a thin cover of clay. A U.S. Geological Survey study of sinkhole flooding in Murfreesboro tracked flooding in 78 sinkholes across three focus areas during storms in February 2001, January 2002 and March 2002, in areas underlain mainly by Ridley Limestone. You don't have to live next to a sinkhole to have the same basic problem: rain that can't soak in quickly moves along the rock surface and into the lowest spot it can find.
Common fixes
- Gutters and downspouts: clearing them and extending downspouts well away from the foundation
- Grading: reshaping soil so it slopes away from the house
- Interior perimeter drain: a trench with perforated pipe around the inside of the foundation, leading to a sump
- Sump pit and pump: collecting water at the low point and pumping it outside, ideally to a spot that drains away
- Exterior drains: a French drain or swale to catch water before it reaches the house
Rock makes a difference
Digging a sump pit or drain trench in shallow limestone can take more effort than in deep soil. Some crawl spaces have ledges or pinnacles of rock close to the surface. The contractor will tell you if the layout has to work around rock.
What affects the cost?
- Length of drain line and how much digging is involved, including through rock
- Sump pit, pump type and whether a backup pump or alarm is added
- Where the discharge line can go
- Outside grading, gutter or downspout work
- Electrical work for the pump
The contractor sets the price after seeing the site. We don't quote prices.
Common questions
Where should a sump pump discharge?
Somewhere the water can drain away from the house and won't flow back toward the foundation or onto a neighbor's lot. Local rules may apply, so ask the contractor.
Should drainage be fixed before encapsulation?
Yes. A sealed liner over a crawl space that takes on water will trap it. Handle the water first or as part of the same job.
Can gutters alone solve crawl space water?
Sometimes. If the water comes from roof runoff near the foundation, gutter and downspout fixes may be enough. Water moving along the rock usually needs a drain and sump.
Where this service is available
Related services
Background on Tennessee licensing, the city code and the limestone under Rutherford County is in the Rutherford County crawl space guide.
Water on the rock, a musty house, or a floor that dips?
Call and we'll put you in touch with an independent crawl space contractor who works in Murfreesboro and across Rutherford County.