Replies

1. Expert Member
   MALCOLM TAYLOR | Jul 30, 2019 07:47pm | #1

   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 | Jul 30, 2019 09:31pm | #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.

   Walta

3. GBA Editor
   Brian Pontolilo | Jul 31, 2019 08:27am | #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 | Aug 05, 2019 10:52am | #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 | Aug 05, 2019 11:02am | #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
   MALCOLM TAYLOR | Aug 05, 2019 11:09am | #6

   https://www.rectorseal.com/sureseal-eliminate-sewer-gas-evaporation/

3. Expert Member
   MALCOLM TAYLOR | Aug 05, 2019 02:54pm | #7

   Might be worth installing one of these: https://www.rectorseal.com/sureseal-eliminate-sewer-gas-evaporation/