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Community and Q&A

Foundation drains out to daylight

AppliedBuildScience | Posted in General Questions on

I have 2 SDR pipes going out to daylight from each corners of my house (downslope). They have been completely exposed and left open. I keep thinking that this is a great way for bugs and critters to get into the house especially since one of my basement floor drains is connected to it. Should I put a check valve on this thing? Recommendations?

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  1. Expert Member

    I've never heard of insects entering a house through the storm drains (but others may have). Rodents however can be a problem. My own preference would be to exclude them at the outfall, rather than let them roam the system looking for a way in, constructing a nest in the dry season, and perhaps blocking the pipes. Screening the outfall also has the added benefit of keeping it, and its location, on your radar. They often get blocked by plant roots travelling up in search of moisture, so annual maintenance to keep it clear is a good idea.

  2. walta100 | | #2

    If we assume the “foundation drain “is draining the exterior of the foundation. I would not be concerned anything getting out of the drain need to tunnel under the footing and then up thru the basement slab.

    I see an interior drain as second line of defense and only useful if it is fully independent. I see connecting the two systems as a design flaw. Should the drain get stopped this connection would allow the exterior drain a direct connection to back up water to the interior!

    My basement slab has a thick layer of gravel under it with a sump pit in one corner so I could add a pump should I ever need one.


  3. GBA Editor
    Brian Pontolilo | | #3

    Hi AppliedBuildScience,

    I think Malcolm is giving you good advice. I've seen rodents' nests in drains so, even if they never enter the house, they can cause problems in the pipe. Best to keep them out altogether.

  4. AppliedBuildScience | | #4

    Thanks! As a follow-up I do have a tight house (.08 ACH) and basement is part of that building envelope. Since that floor drain is connected to the exterior drain pipes I wonder if this will have negative consequences to air tightness since it can pull in air from this drain. I suppose I'll need to keep the cap on the floor drain and put a screen on the outside of the pipe to prevent pests.

    1. GBA Editor
      Brian Pontolilo | | #5

      What was the status of the drain when the blower door test was performed? Was it blocked? At that rate or air tightness, I assume it was. So, I guess if you want the house to continue to operate at .08 ACH50, you need to keep the drain capped.

    2. Expert Member
    3. Expert Member
      MALCOLM TAYLOR | | #7

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