We bought our new Chattanooga, TN home in August and it is ~3 years old. The crawlspace has some water penetration on one side of our house. We live on a hill and the water is penetrating on the side of the house that is downhill from our neighbors.

The home inspector pointed out the water in the crawlspace and recommended we get a French drain installed on that side of the house.

I am reading conflicting things online about whether or not an exterior French drain will solve the problem or if we will need to get an interior French drain and sump pump installed in the crawlspace.

Here are some pics of the where the water penetrates. We don't get "flooding", but it is regularly wet. The black pastic in the pics is from the builder installing platic in the crawlspace that coveres the dirt floor and side walls. The builder also installed a drain pipe at the corner of the crawlspace where water is most likely to run to.

I have had some crawlspace experts come out and offer $10k-$20k quotes for encapsulation, and installing a dehumidifier and sump pump, but that seems like overkill for my situation.

Any suggestions on how to address this? Should I start with the exterior French drain?

Should I try putting some flex seal on the spots in the cinder blocks where water is penetrating?

My biggest concern it to prevent mold from developing.

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1 Answer 1


There's three things you should explore here

  1. Waterproof the wall from the outside
  2. Make sure you have appropriate weeping tiles (they should be next to your foundation footings)
  3. Make sure the ground does not permit ponding next to your foundation where this is happening (i.e. your gutters don't channel the water away from the house)

Sump pumps are mainly for situations were the water comes up from underneath the foundation. That's not the case here. Unfortunately, this means excavating that side of the wall to fix it. You might need professional help here.

  • 2
    I'd add #4: Ventilation. It can cure many ills with slow-moving water.
    – isherwood
    Commented May 6, 2023 at 17:19
  • @Machavity Thanks for your comments. What kind of professional should I look for regarding waterproofing the wall from the outside? Landscaper? Commented May 6, 2023 at 17:41
  • @TodBirdsall You want a basement or foundation specialist. They're not hard to find in your area. The Better Business Bureau even has a list
    – Machavity
    Commented May 6, 2023 at 18:49

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