Crawl space drainage and sump pumps
If water collects under your house after rain, it needs somewhere to go. Here's how crawl space drainage works on eastern NC's low ground.
Standing water in a crawl space feeds humidity, soaks insulation and can weaken piers and framing. With more than 50 inches of precipitation in a typical Greenville year and tropical systems that can drop far more in a few days, drainage is often the first thing to fix.
Start outside
- Gutters and downspouts. Clean gutters, and extend downspouts so roof water lands well away from the foundation.
- Grading. Soil should slope away from the house. Flowerbeds and settled backfill often create a dip that holds water against the wall.
- Surface drains. On flat lots common in Pitt County, a swale or yard drain can carry water away.
Then inside
When outside fixes aren't enough, or the water comes up from below on lots with a high water table, an interior drain can help. A perforated pipe set in a trench around the inside of the foundation collects water and carries it to a sump basin, where a pump sends it out of the crawl space. The vapor barrier or encapsulation liner goes over the top.
What to ask about a sump system
- Where will the pump discharge, and is that away from the house and the neighbors?
- Does the basin have a lid, and is it sealed under the liner?
- Is there an alarm or a battery backup for power outages during storms?
- How do I check that the pump is working?
Warning signs
- Puddles or mud under the house a day or more after rain
- Water lines or staining on foundation walls and piers
- A liner that floats or holds water on top
- Efflorescence, the white crust on block walls
Flood zones
Homes near the Tar River and its creeks can see water levels no drain is built to handle, as Hurricane Floyd showed in 1999. Drainage helps with routine rain and groundwater. For flood risk, check your property on the FEMA flood map and talk with your insurance agent.
The crawl space company prices the job after getting under the house and measuring. We don't quote prices, and any number given over the phone before an inspection is only a rough starting point.
Where we connect you with help
Common questions
Do I need a sump pump in my crawl space?
Only if water collects there that outside fixes like gutters and grading can't stop. A crawl space company can tell you after seeing it, ideally after a good rain.
Will a sump pump protect my house in a hurricane?
Not from river or creek flooding. It handles routine rain and groundwater, not floodwater rising across the property.
Related services
- Encapsulation and vapor barriers
- Crawl space dehumidifiers
- Damp and musty crawl spaces
- Sagging floor and joist support
More background: Greenville, NC crawl space guide.
Musty smell, damp insulation or a soft, bouncy floor?
Call now and a local crawl space company will help you figure out what's going on under the house.