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Basement drain cover

JosephusArchitect | Posted in Construction Techniques on August 8, 2013 05:30am

This is my first post…we purchased an older (1928) home a year ago and just experienced some flooding in the basement and discovered that the drain had this inverted bowl on the bottom of the drain cover plate that prevented any water going down the drain, at least when I removed the cover the water went down immediately.  Can anyone tell me what I’m looking at here?

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  1. User avater
    Mike_Mahan | Aug 08, 2013 06:52pm | #1

    Perhaps your basement was designed as a giant bathtub and the drain cover is some kind of pop-up?  Maybe it's not a drain at all but a hydrostatic relief valve designed to keep you basement from floating away. You have a high water table or anything?

    Thanks for not spamming the forum. It would seem most first time posters do.

    1. JosephusArchitect | Aug 08, 2013 07:02pm | #2

      well it seemed to look like that this morning :).  The inverted "bowl" is fastened to the cover with a wing nut and is not moveable, so I'm wondering if the previous owner was worried either about little creatures coming up the drain pipe or perhaps water coming in as opposed to going out, and used this as a means to prevent that.  There have been reports of water coming up basement drains in our neighborhood... by the way, the drain pipes are connected to the storm drain system and not the sewer.  Do you have any basement floor drain recommendations for situations where water does sometimes back up...when it's on overload during a storm like we had last night?

      Re: not spamming....like advertising???

  2. DanH | Aug 08, 2013 07:58pm | #3

    That may at one time have been part of a backflow check valve, or a manually operated backflow valve.  No telling what parts may have rusted apart and floated away.

    There are various styles of check valves that can be installed as a part of the drain, for backflow protection.

  3. user-1116010 | Aug 09, 2013 05:38am | #4

    Thats the top portion of a bell trap, and you may be able to put it back into service. The inverted bowl is meant to hover over the pipe in the bottom of the receptor, slightly below the top edge of the pipe.

  4. user-1116010 | Aug 09, 2013 05:38am | #5

    Thats the top portion of a bell trap, and you may be able to put it back into service. The inverted bowl is meant to hover over the pipe in the bottom of the receptor, slightly below the top edge of the pipe.

  5. user-1116010 | Aug 09, 2013 05:38am | #6

    Thats the top portion of a bell trap, and you may be able to put it back into service. The inverted bowl is meant to hover over the pipe in the bottom of the receptor, slightly below the top edge of the pipe.

    1. DanH | Aug 09, 2013 06:31am | #7

      OK, so that's a poor man's trap, and without it the drain is likely not protected from gasses venting back into the basement.

      Does the drain run to the sanitary sewer or somewhere else?

    2. JosephusArchitect | Aug 09, 2013 06:56pm | #14

      thank you for the explanation, but I'm going to remove it as I plan to also remove the source of any sediment coming from outside the basement via the garage door (am going to install a 2" high threshold), so a backflow preventor is going to have more value to me at this point than something that separates out any sediment.

  6. Wally's Workshop | Aug 09, 2013 07:51am | #8

    Floor drain

    This is a floor drain found in a lot of older houses.  My house was built in 1933 and I have a similar one in my basement.  I did have a shower and stool and cement tubs in my basement and experienced flooding once during a real heavy rain.  I too am hooked up to the city sewer/water runoff system.  Sometimes there is a plastic ball that prevents water from backing up thru that drain.  I took mine apart and put in a expansion plug in the hole so I am sure no water will back up the floor drain.  I can take it out if needed and drain any water from the floor.  I also put in a sewerage injector for the toilet and shower and tub sinks.  Now all my water in my basement goes into the sewerage injector and gets pumped up higher into my main drain. I have never had any problems with heavy rains again and I did this 10 years ago.  We can go on vacation and be assured of a dry basement.

    Wally

  7. rdesigns | Aug 09, 2013 10:22am | #9

    The bell has nothing to do with preventing backups or with creating a trap--its purpose is to divert water-borne sediment off to the sides of the receptor in the body of the floor drain where sediment is captured in an outer circular depression which has an inside ridge with notches to allow cleared water to flow over and down into the drain.

    You need to clean the junk out of the receptor occasionally, and that's why the lid and bell are joined as a unit that tilts back on a hinge to allow access, or, in some cases, there's no hinge; you just lift the unit off for cleaning access.

    1. JosephusArchitect | Aug 09, 2013 06:53pm | #13

      thank you for your good explanation here.  I will clean the receptor out and am removing the bell and plan to install a Trapguard backflow preventer. 

  8. sapwood | Aug 09, 2013 11:11am | #10

    rdesigns is exactly correct. This device is an inexpensive and poor working sediment trap. My last house had one of these in the garage. It required frequent maintenance because our vehicles would track in a lot of sand during the winter. Snow water would carry the sand to the drain that would eventually get clogged at the rim. We sold the house before I ever took the time to install a proper sediment trap. 

  9. shazapple | Aug 09, 2013 03:17pm | #11

    It could be a old Bell trap?

    1. JosephusArchitect | Aug 09, 2013 06:51pm | #12

      Yes, that is exactly what it is, an old Bell trap.  The basement drain pipe (AFIK) is hooked up to the storm drainage system, and not the sewer, but when we have flash floods (like a couple of days ago), it can and will back up and actually bring water INTO the basement, the bell trap does not do anything as far as preventing backflow.  I am removing the bell traps (I have two of these drains) and putting in a Trapguard which will prevent water from coming back up in those rare occasions.  Usually the drains are dry.  Thank you all for your help with this.

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