Basement
Wet basement in Roswell: finding the cause
A basement can be wet without a single drip. Before spending money, find out whether the moisture is coming through the concrete or out of the air. The answers lead to very different work.
You talk with an independent local waterproofing company. Roswell Crawl Space is a referral service and does none of the work itself.
Two reasons a basement is wet
- Soaked soil against the wall. After rain the ground holds water, and its weight presses moisture through concrete and block.
- Water under the slab. The same pressure pushes up through floor cracks and the joint at the wall.
- Humid air on a cool wall. Summer air let into a cool basement sheds water on the masonry, like breath on a window.
- A sweating pipe. Cold water lines drip for the same reason and wet whatever is below them.
The foil test
Dry a patch of wall with a towel. Tape a square of aluminum foil or plastic wrap to it, about the size of a sheet of paper, with tape along all four edges. Leave it for a day or two.
Beads of water on the room side of the foil mean condensation: the air is the source. Dampness underneath, with the wall darker than the area around it, means moisture is coming through the wall. You can get both.
Do the same on the floor. The test costs almost nothing, and a company should take the result seriously.
Fix it in this order
Roof water
Clean the gutters and carry every downspout several feet from the wall. Start here because it costs little and is easy to undo.
The ground beside the house
Soil should fall away from the foundation on all sides. Beds built up against the wall hold water there.
The air
Keep basement windows shut in humid weather and run a dehumidifier that drains by hose. Insulate cold pipes.
The wall and floor
If water still comes through, look at leak repair for one spot or an interior drain for a whole wall.
What to hold off on
Do not frame, insulate or carpet a basement that fails the foil test. Finishes hide moisture and feed mold behind them. Sort the water, give it a full wet season, then build.
Hold off on waterproof paint as well. It can help against light dampness. Against real seepage it peels, and the flakes make it harder for anyone to see what the wall is doing.
White, chalky deposits are mineral salts carried out by water and left when it dries. Brush them off and watch how fast they return. That tells you how much water is moving.
Wet basement questions
Is some dampness just normal for a basement?
Concrete below ground is rarely bone dry. Damp that you can smell, that marks the walls or that ruins what you store there has a cause you can find.
Will a dehumidifier alone solve it?
If the foil test shows condensation, quite possibly. If water is coming through the wall, the machine will run without rest and still lose.
What does a company look at on a visit?
A careful inspection takes in the gutters, the slope of the yard and the outside of the wall before the inside. The guide to choosing a company lists what else to expect.