Before you buy a fix
Wet basement: work out which kind of wet
"Wet basement" covers three different problems that look alike on a bad day: moisture from the air, moisture soaking through masonry, and water running in. They have different cures and very different costs. Ten minutes of checking tells you a good deal.
Call (205) 555-0115Three checks you can do today
Tape a square of plastic to the wall
Use clear plastic or aluminum foil about a foot square, taped on all four edges, on a spot that gets damp. Leave it two days. Droplets on the room side mean the air is the source. Damp behind it means moisture is coming through the wall.
Watch what the weather does
Damp that follows rain by a few hours is coming from the ground outside. Damp that is worse on muggy days with no rain is condensation. Damp that never changes may be plumbing.
Walk the outside in the rain
Take an umbrella and look at each downspout, each corner and each paved area by the house. See where water lands and which way it runs. This is the check people skip, and it finds the cause more often than any other.
Look at the base of the walls
A white, powdery line near the floor is mineral salt left by evaporating water. A tide mark on stored boxes or the furnace base shows how high water has stood.
If it is the air
Basement walls and floors stay cool in summer. Humid air touches them and gives up its moisture, the same way a cold glass sweats. Opening basement windows in July makes it worse, not better. Keep them shut, run a dehumidifier sized for the room, insulate cold water pipes and make sure the clothes dryer vents outdoors. If that dries the room, you did not need waterproofing.
If it is soaking through
Start outside, because it costs little. Clean the gutters. Add extensions so every downspout lets go several feet from the wall. Pull mulch and soil back so the ground falls away from the house. The Environmental Protection Agency gives the same advice in its moisture guide: make sure the ground slopes away from the foundation.
Give those changes a few good rains. If the walls are still damp, the water is arriving through the soil itself and the choice becomes a drain on the inside or a membrane on the outside.
If water is running in
Follow it back. If it starts at one crack or one pipe, read basement leak repair. If it wells up where the floor meets the wall along a whole side, or rises through cracks in the slab, the soil under and around the basement is filling with water, and a drain and sump pump are the usual answer.
Water that comes up through a floor drain, especially if it is gray or smells, is the sewer backing up. That is not groundwater, and who to call depends on which part of Hoover you are in. The local rules page lists the numbers.
Finished basements: what to protect meanwhile
Carpet, carpet pad and the bottom edge of drywall hold water long after the floor looks dry. Lift what you can, move furniture off wet carpet and run fans and a dehumidifier. Take photographs with dates. The EPA's guide says wet materials should be dried within a day or two to head off mold, so drying comes before deciding on a permanent fix.
When you do call, have this ready
- Which walls or which part of the floor get wet
- Whether it follows rain, and how soon
- What the walls are made of: poured concrete, block or brick
- Whether the basement is finished
- What you have already tried outside
- Whether there is a sump pump now, and if it runs
Wet basement questions
Is a damp basement normal in Alabama?
Slight dampness in the air in summer is common and a dehumidifier handles it. Water on the floor, wet walls or a persistent smell are not something to accept.
Will a dehumidifier fix it?
It fixes condensation. It does not stop water coming through a wall or a floor joint, and running one against a steady leak mostly runs up the electricity bill.
Should I wait and see?
Watching through two or three storms is sensible, provided you are recording what happens. Waiting a year with wet carpet is not.