Basement fix
Most disappointing basement repairs fixed the wrong problem. Name the problem first, then pick the repair.
The right basement fix depends on what is wrong: damp air, water seeping through the wall, a leak at a crack or joint. Or a wall that is moving. Each one has a different repair, and a fix for one will not help the others.
This page prints no prices. It helps you sort the problem so you can judge what you are offered.
Sort the problem into one of four bins
- Damp air. The wall is cool and drops form on the surface. This is a ventilation and humidity job.
- Seepage. Water works through the masonry after rain. The cause is usually outside.
- A point leak. One crack, one joint or one pipe. It leaks in the same spot each time.
- Movement. The wall leans, bows or shows long horizontal cracks. This is structural.
The wet wall page has a two-day test that separates the first two.
The cheapest fixes are the ones outside
Take a position: start outside, every time. Lengthen the downspouts. Clear the gutters. Slope the soil away from the wall. These cost almost nothing to try, and plenty of basements dry out with only that. Watch the wall through the next heavy rain before you go any further.
Then match the repair to the bin
For seepage that stays after the outside is sorted, the real choice is between inside drainage and outside waterproofing. The interior vs exterior page compares them. For one crack, a targeted repair may be enough, and the leak repair options page shows the range.
Coatings are the weakest answer. A thin layer resists dampness, not water under pressure. See foundation coating for where one fits.
When the fix is not a sealing job
If the wall leans or bows, stop thinking about sealing. That is a structural question. A licensed structural engineer should look at it, and an independent one has no repair to sell you. Do not dig beside a wall you suspect is under strain, because that can make it worse.
How to judge a proposal
Ask what problem the proposal says you have, and how it knows. A good answer names the source of the water. A weak one jumps straight to a product. Ask what happens in a power cut if a pump is involved, and where the water will be discharged. Get it in writing and compare more than one.
Check local rules
Drainage, sump discharge and permits are set by your state and town. Ask your building department what applies before any work starts.
Frequently asked questions
What is the best basement fix?
There is no single best fix. It depends on whether the problem is damp air, seepage, a point leak or wall movement. Name the problem first.
What should I try before paying for a repair?
Work outside first: extend downspouts, clear gutters and slope the soil away from the wall. Then watch the wall through a heavy rain.
Does a coating fix a wet basement?
Usually not on its own. A coating resists dampness but not water under pressure, so the source has to be reduced first.
When is a basement problem structural?
A leaning or bowing wall, or long horizontal cracks, point to movement. That needs a licensed structural engineer, not a sealing product.
What should a repair proposal include?
It should name the source of the water, say where the discharge goes, explain what happens in a power cut, and be written down so you can compare it.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.