Basement and crawlspace water in Wilmington
Whether a Wilmington house has a basement, a crawlspace or a slab, water below the floor causes the same trouble: musty air, rot, mold, rusted ductwork, sagging floors and pests. Waterproofing companies sell systems that range from a gutter extension to a full interior drain with a sump pump and an encapsulated crawlspace. The right answer depends on where the water is coming from, so start there.
Find the source first
Water gets below a house in a few ways, and each has a different fix:
- Surface water: rain from the roof and yard that runs toward the house and soaks in along the foundation. The fix is usually gutters, downspout extensions and grading.
- Groundwater: water in the soil that rises around and under the foundation after long rains. Fixes include perimeter drains and sump pumps.
- Humidity and condensation: damp outdoor air entering a cool crawlspace and condensing on pipes, ducts and wood. The fix is about air and vapor control, not drains.
- Plumbing leaks: a dripping supply line or drain under the house. A plumber fixes this, not a waterproofer.
Before you get quotes, look around the house during and after a heavy rain. Note where water collects, whether gutters overflow, and whether the crawlspace or basement gets wet right away or a day later.
Groundwater in the area
The Cape Fear Public Utility Authority draws about 20 percent of its raw water from wells in the Castle Hayne and Peedee aquifers beneath New Hanover County, and the rest from the Cape Fear River upriver at Kings Bluff. That tells you there's water in the ground beneath the county, but it says nothing about the water table under any one lot. Ask a contractor what they see on your property: water marks on foundation walls, standing water in the crawlspace, efflorescence or rust.
Drainage outside
The least expensive repairs are often outside: clean gutters, downspouts carried well away from the foundation, and soil that slopes away from the house. Ask any waterproofing contractor whether they've checked these first and whether they recommend fixing them before or alongside a larger system.
Interior and exterior systems
- Interior drains and sump pumps collect water that gets in and pump it away. Ask where the discharge goes, whether the pump has a battery backup and how the pump will be maintained.
- Exterior waterproofing digs down along the foundation to apply a membrane and a drain. It's more disruptive and costs more, but stops water at the wall.
- Crawlspace encapsulation lines the floor and walls with a vapor barrier, seals vents and often adds a dehumidifier. Ask how the space will be dried and whether the dehumidifier drains to a pump or outside.
The license threshold
The North Carolina Licensing Board for General Contractors says that by law a general contractor must hold a state license when the total cost of a project is $40,000 or more, and the board's website has a public license search. Many waterproofing jobs cost less than that, but larger ones, especially exterior excavation and structural repairs, may not. Ask whether the contractor holds the license, look them up on the board's search and ask whether the job needs a permit.
Comparing quotes
Ask every company to say in writing where they think the water comes from and why their system fixes it. Then compare: the scope, the materials, pump type and backup, discharge location, dehumidifier, any structural repairs, permits, cleanup and the warranty, including whether it transfers to a buyer.