Remove the plastic vapor barrier from the crawl space, if one is present, by pulling it up from the floor. Properly dispose of it.
Check the crawl space for mold, rotting wood and insects, all signs of long-standing water problems. Fix any major problems related to these conditions before proceeding.
Dig a trench using a small shovel, 8 to 24 inches from the foundation walls and at least 4 inches deep, to protect the crawl space parameters.
Lay a 3-inch socked flex perforated pipe the full length of the trench to remove any water out of the crawl space. A socked flex perforated pipe is a ribbed, flexible pipe designed with many holes to capture the water and move it toward a designated exit, such as a sump pump.
Locate the lowest part of the trench to install a sump pump; this generally requires digging a pit that can hold the pump. Place the socked flex perforated tubing so it will drain directly into the sump pump. Make sure the sump pump removes the water to the outside of the crawl space and away from the foundation.
Cover the pipe in the trench with 1 1/2 inches of pea gravel. Cover the pea gravel in the trench with dirt.
Install a new vapor barrier by stretching it out and covering the entire floor of the crawl space. Cut openings to accommodate any support beams, if needed.
Dig a small trench, about 4 inches deep, around the outside of the house to help prevent water from standing and seeping into the crawl space again. Add landscaping to encourage water to drain away from the house.
Things You Will Need
- Small shovel
- Measuring tape
- Socked flex perforated pipe, 3-inch diameter
- Sump pump
- Pea gravel
- Vapor barrier, 6-mil vinyl
- Investigate the reason behind the water under the crawl space. Rain or water-soaked grounds and poor-draining soil are usual causes.
- Wear safety eye gear when digging under the house.
- Consider a rebreather when you work in an area with restricted ventilation.