Had a home inspection recently that indicated this drain may not be trapped. It's a wet bar in my basement that we've never used since we bought the place. The sink works fine, just never used it.

The main drain for the house runs somewhere near there. The laundry room is in the next room and that is where the main drain for the house is located (public sewer). The main drain is about 10ft from this sink.

Is there any simple tests I can do to determine of there is a trap in the concrete or if it's protected by another trap?

enter image description here

  • Pour some water down the drain --> disconnect the drain --> take a flashlight and look into the drain where it enters the floor --> if the drain pipe has water in it then it likely has a trap. Commented Nov 25, 2016 at 23:17
  • 1
    I think the inspector was talking about the sink itself, not having a trap. The main sewage under the floor would most likely NOT have traps, as they would be difficult to service. From your picture, there doesn't appear to be a trap, between the sink, and the floor - this would be illegal, in most localities.
    – tahwos
    Commented Nov 26, 2016 at 2:03
  • @tahwos if that's the case then he wouldn't have left it as a question would he? It would have been stated as fact I think. Also, I know the floor drain in my laundry room is trapped which would require a jackhammer to replace if it's ever necessary. I'm assuming the inspector left it as a question because there is a possibility of a similar trap under the bar for that drain. If the trap is simply missing, it's an easy fix but I have to determine if there is already a trap buried in the concrete or risk double-trapping this sink which I've read is a huge no-no without a vent between them which
    – kinar
    Commented Nov 26, 2016 at 2:16
  • @kinar, Call him up and ask him... and why they would put your laundry trap, below grade is a mystery too, they are normally, just above the finished floor, for serviceability... but maybe you live in one of "those places", where it doesn't really matter, or your house is just that old. If you really want to know, by a cheap "bore camera" on Amazon.
    – tahwos
    Commented Nov 26, 2016 at 2:35
  • @tahwos call and ask. Good suggestion (seriously). Can't hurt. House was built in 78.
    – kinar
    Commented Nov 26, 2016 at 2:37

1 Answer 1


Borescopes on Amazon

The cheap and easy way - purchase a camera and look.

Most newer USB-OTG capable phones will work with USB Borescopes/Endoscopes/webcams.

I am using the same USB scope that I bought years ago for use with my laptop, as a borescope for my Samsung S7 phone.

Paired with the free app IP Webcam and/or native Android WiFi screen casting, it has proven quite indispensable in contrast to how little it cost to purchase online.

  • Good idea. I've already got one of these on order, arriving today, for another project I'm working on.
    – kinar
    Commented Nov 26, 2016 at 15:14
  • They really do come in handy, in places where your head won't fit.
    – tahwos
    Commented Nov 26, 2016 at 16:52

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.