I just bought a house that was built in the early fifties, with an unfinished basement. Recently, after a heavy rainfall, some water leaked into certain parts of the basement (see photos).

enter image description here enter image description here enter image description here

This is a new issue for me, so I have questions:

  1. This post, which describes a situation similar to mine, mentions the possibility of a French drain. How do I determine whether I have one?
  2. How, if at all, can I prevent this from happening again?
  3. If occasional seepage is unavoidable, how can I mitigate or minimize it?
  • Next time it rains spend some time in the basement and try to determine exactly where the water is coming from. You might find some small cracks you can fill with a leak stopper.
    – JACK
    Jul 29, 2019 at 19:45

1 Answer 1


Always start with correcting the grade around the house - i.e. the shape of the soil. It should slope AWAY from the house at at least 1/8" per foot (or 1 cm per meter) for 10 feet or 3 meters. If there is settling, pooling, or unfortunate past choices causing that not to be the case, correcting them (if at all possible) is a huge help to basement water issues.

If there are gutters, verify that the water from them is carried well away from the house.

If the problem persists, then you get into the difficult stuff (underground work.)

One step towards mitigation is to raise items in the basement on bricks or the like so that a small amount of water in the basement is not getting things that will be bothered wet. My basement freezer is sitting on 4 bricks, which are mortared to the floor to make them stable and level (as the floor is not level there.) Likewise for wooden workbench.

  • The ground definitely appears to be flat. How do I check the grade? Do I rent a surveyor's scope or something?
    – crmdgn
    Jul 28, 2019 at 21:22
  • 3
    Nothing so fancy needed. An 8-10 foot (straight) board and a level set on the board should be entirely adequate. If the board is set on the ground, and the level is set on the board, and the end away from the house is raised on a block, the level will tell you if you have adequate slope in that spot. You can use a block taped to the end of the level, 1/8" thick for every foot long the level is, and set the board directly on the ground. i.e a 1/4" block for a 2 foot level, a 1/2" block for a 4-foot level.
    – Ecnerwal
    Jul 28, 2019 at 21:39

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.