Standing water causes wet, musty, and moldy conditions in a crawl space. A flooded crawl space is constantly releasing water vapors into the air and increasing the overall humidity.
The worst problem with flooding is a crawl space is when the standing water is on top of the vapor barrier. The vapor barrier prevents the water from draining, which essentially traps the water in the crawl space, constantly releasing moisture into the air. So while the vapor barrier actually contributes to the damage from a flooding problem, it’s still absolutely necessary to control the moisture from the damp earth.
Often times, most people are not aware that their crawl space floods. It’s not until a professional inspector identifies the signs of flooding or if someone inspects the crawl space immediately after a heavy rain, that people discover there is standing water in the crawl space. To identify past flooding instances, look for straight horizontal watermarks on the piers and walls, look for dirt on top of the vapor barrier, and look for wet soil along the crawl space perimeter.
The main causes of standing water in a crawl space are a combination of the following:
- Heavy or prolonged rains
- Snow melting
- Wet or “marsh-like” property
- A shallow, clay-soil layer
- The crawl space is “below grade” meaning the crawl space is lower than the outside ground
- The outside ground is not graded away from the home
- The gutter downspouts discharge right next to the house
- A depression in the soil near the house collects water
- A concrete patio slopes towards the house… common with swimming pools
- Plumbing leaks
The goal of any homeowner with standing water in the crawl space should be to prevent future flooding instances. Standing water can cause significant issues if left unresolved.
To prevent and remove water in a crawl space, you can take the following steps:
- Install a French drain along the perimeter of the crawl space with sump pumps
- Install sand in low-lying areas… not effective to stop flooding in a whole crawl space
- Install gutters with downspout extensions
- Install ‘door-wells’ around crawl space access doors
- Fix plumbing leaks
We don’t recommend a single ‘one-size-fits-all’ approach to fixing the issues. A well thought out plan, by a trained professional, will get the best results. The whole issue including how it was caused, how severe the problem is, and the conditions of the property should determine the best path forward.