We have a foundation drain in our home that works OK. However, I've seen that over time it starts to accumulate this red colored sand deposited on top of the drain (where the gravel is), which slows the drainage of the water during heavy rain and causes it to spill onto part of our basement. The stone-foundation of the house is right next to the drain, so I'm thinking it's water from the foundation bringing deposits onto it.

Is there a way to prevent sand from depositing on top of the drain pipe?

Here is a picture after we removed the drywall and patched up foundation (I hired out for this). They also attached some 'water proofing shield' into the foundation, it routes the water into the drain. The drain is at the bottom there. I unfortunately don't have a photo of the drain as of right now because we closed up the wall.

picture of the foundation

  • Please edit to include pictures. If it's happening at the surface where you can see it, the sand has to come from somewhere on that level. If it's happening underground and you have to dig a hole to see it, you didn't mention that and something along the lines of filter fabric might help.
    – Ecnerwal
    Mar 3 at 14:14
  • No problem, will add photos. It's behind a drywall unfortunately. I took off the drywall 6M ago when we cleared out the french drain and patched foundation, but then closed up the wall b/c I thought the problem was solved. I'll share photos without the wall.
    – David
    Mar 3 at 14:17
  • 2
    A french drain inside the building? OK, that's a new one on me, or not the way that term is generally used IME.
    – Ecnerwal
    Mar 3 at 14:20
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    French drains transfer water from higher to lower points outside with no pump involvement. You have a "drain tile" system if it dumps into a sump. It's possible you do actually have a French drain originating inside and flowing out under the foundation, but that's a rare case.
    – isherwood
    Mar 3 at 16:06
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    @isherwood you're right, this drains into a sump pump which is just off to the left of the picture above (the dehumidifier you're seeing also drains into that sump pump too)
    – David
    Mar 3 at 17:07

1 Answer 1


If gravel was actually used over the tile and not washed & screened rock, it's no big surprise that you're having issues already. Sediment is a fact of life with foundation drainage systems. It's the reason that it's critical to build such systems in anticipation of silt, commonly with washed rock reservoirs and protective silt-blocking fabric.

Even then, eventually they'll clog and fail. Usually the only solution is to open and rebuild the drain circuit, excavating the silt soil.


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