I have a foundation vent that lets water into the basement and leads to flooding when it rains. I have plenty other vents and so I would like to completely close this one. The water comes in because the water collects in the flower bed outside the house.

I want to seal it. And I am looking for suggestions on how to do it. I am a new homeowner. Don’t know much about all this.

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  • Have you got a photo of the outside ?
    – Criggie
    Jan 11 at 18:31

1 Answer 1


I'd suggest that the problem is the flower bed, not the vent. Grade should be reduced and sloped properly to prevent the problem. Consider rain gutters in the area. You could also switch to a flower box to keep soil away from the foundation. Obviously the vent was installed to provide fresh air to the crawl space, preventing mold and decay, and it should probably be retained.

If you do want to close it, the usual course of action is to remove the vent and install concrete as per the rest of the wall. This could be in the form of bricks or blocks mortared into place rather than poured concrete, but it would provide a good basis for a waterproof coating.

You could also mount a rot-resistant panel of some sort (vinyl, metal) into the opening and caulk it to the existing concrete or fasten it to the surface with a neoprene gasket using concrete screws.

  • 1
    Thank you for your suggestion. Can you also help with how to do the first part. What does grade mean and how to change the slope? On your second part can you tell me any products or pictures that would help me look for things
    – Apna
    Jan 10 at 15:18
  • 3
    There are many good questions and answers on this site covering both topics. Your question is spreading in scope. Please take the tour and see the help center. Post a new question if you've searched and not found what you need.
    – isherwood
    Jan 10 at 15:22
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    The first step would be to lower the level of the flower bed by removing soil and/or place a drain in the flower bed to prevent the pooling of water next to the foundation. We need a picture of the foundation on the outside. If there a roof gutter drain that is disgorging water that is pooling then add an extension to direct the water out away from the foundation. Sealing the opening would not be the best option to prevent water flowing in. The water should not be allowed to pool in the first place. Jan 10 at 16:57
  • @Apna Grade refers to two things. 1. Soil gradation. A flower bed (and just about all landscaping) will have multiple grades, you can roughly think of them as layers. A rough grade for drainage and flow of excess water. A top grade over it (sometimes called a final grade or finish grade) with topsoil. 2. Slope and height. Rough grading is getting the overall shape and slope in place. When done incorrectly, basements will flood. Remove the excess material, put in a new rough grade low enough and put finer grade over it. Basically, lower the bed.
    – Mast
    Jan 11 at 22:59

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