Condensation on UNDERSIDE of toilet BOWL - detailed history - please help!

Discussion in 'Toilet Forum discussions' started by simoninatree, Apr 3, 2013.

  1. simoninatree

    simoninatree New Member

    Apr 3, 2013
    We have a 30 year old house and finally decided to change out the toilet in the half bath. It showed an intermittent leak by the grout line (tile floor). Due to the no smell and lack of consistency, this was not seen as a concern for a long while.

    We installed a Champion 4 Max and watched it for several days (without caulking it) for observation. On day 4 we noticed the grout being slightly wet in one spot. We pulled it and reset it 3 times with the leak worsening each time. We started testing with tissue paper glided under it to see if it was wet, so we were noticing the water sooner than if we just waited for it to appear on the floor. We checked for leaks at the tank or water supply - none.

    We called a plumber who reset it and left the grout off for our observation. Next day -- wet again. We called him back. He checked for leaks at the tank or water supply - none. He pulled the toilet -- wax ring sealed well -- and based on some streaks on the underside, concluded there was a crack in the bowl.

    We exchanged the bowl for another Champion 4 Max. Before installing the new one -- the plumber suggested we do it ourselves because it looked like we set successful wax rings -- we noticed bad glazing and returned it. We changed to the Delta Prelude based on recommendation and report of success by the plumber. One day after installation, the Prelude had water under it as well. We pulled the toilet and set it in the garage and put water and blue food coloring in it -- no bowl leak and no cracks observed. We reinstalled it. Again, there was water under the toilet. We checked for leaks at the tank or water supply - none. But we saw large condensation droplets all over the underside (inside where it is not smoothly glazed).

    We called the plumber again. He investigated it, did blue dye test, checked for water leak by checking meter, and checked floor temperature.

    1) Water is not from the flush -- it takes time for it to appear.
    2) Water is not blue, even though we are flushing blue water. (I have verified that the tissue will show pale blue if I dip it in blue water.)
    3) One floor tile is 81 degrees while the rest are 70-71 degrees. This single warm tile is where a hot water pipe goes to the washer in the next room.
    4) There is missing concrete where the lead pipe leads through the foundation (slab). Hence there is space between the plumbing pipe and the foundation. This is covered by the wax ring when it is spread with toilet placement, but it is still of interest.
    5) Warm air from earth below foundation is working its way through this space to enter the underside space of the bowl and is causing condensation under the bowl. This drips eventually to cause a puddle (noted each time we pull the toilet) about 1 inch in front of the closet flange. Eventually, if left long enough, it will drip down the sides (inside) of the bowl and a tissue touched just beneath the side of the bowl will absorb it, before it is leaking out.

    Recommendation by plumber is to fill the gap between the pipe and the foundation with cement or something to prevent the warm air from the heated earth from coming through this space and causing condensation on the underside of the bowl.

    Steps Taken & Results:
    1) Put concrete caulk around pipe. It fell 'to China'.
    2) Squeezed in cement around pipe. A lot of cement due to its falling 'to China' multiple times. Let this set for 2 days but it started settling also -- but was still in sight.
    3) Dug out cement (which was still damp) and filled with spray foam sealant. Still had some tiny crevices visible but they also had foam under them so we were not certain if air came through.
    4) Tested it for condensation formation using a glass bowl inverted over drain. (Sewer pipe is plugged for gas escape but testing the crack around it). Heavy condensation over whole bowl with dripping down to floor.
    5) Smeared crevices with Loctite putty. Tested with bowl again, less condensation (fine mist on 1/2 of bowl with no dripping). Puttied more... and more until we had no condensation. None until 3 days ago when it rained and a very fine mist formed and it resolved itself (no drip and total dissipation on its own).
    6) Reset toilet with high hopes at 7AM yesterday. Filled with water and added blue coloring to bowl. Flushed - checked - nothing. 8AM - checked again - nothing. Checked again at 9PM - wetness about 1 inch in front of flange as well as closer to flange (based on insertion depth of tissue under bowl). Water appears to be condensation because it is clear not blue. (Of course we had a light rain yesterday and all night -- for a change.)

    What next? This has been going in for 1 month. We have concluded the original problem was probably condensation as well. We could just caulk it and ignore it... we have a slab with tile -- no sub-flooring to rot... But it seems mold and fungus would grow. We asked our plumber if we were expecting too much for it to be dry underneath. He answered 'no - not at all -- it would grow (stuff)'...

    Side notes:
    1) We have cast iron plumbing beneath house and had lines checked 1 year ago for roots, leaks, etc by Roto-Rooter camera -- nothing was found. That was when we had initial concern based on smell in another bath -- resolved with drain cleaner, Bio-Rooter, applied monthly.
    2) Sewer flies invaded the 1/2 bath currently in question -- which is why we pressed getting new toilet to begin with...
    3) My niece had this happen in a house in Austin, TX, and it seems their plumber sealed it. She is not sure how, but seemed to think just around the bowl. (Caulking it in??)

    Any suggestions would be welcomed...

    Last edited by a moderator: Nov 7, 2013
  2. kreemoweet

    kreemoweet In the Trades

    Sep 7, 2009
    Seattle. WA
    I would be asking why there is such a large void under the toilet flange, and why is it so wet? Did you say there's a 30- year old
    lead bend going down under the flange? Hmmm, do you think it could possibly be leaking? Hmmm, Hmmm!
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  4. simoninatree

    simoninatree New Member

    Apr 3, 2013
    I thought I had that covered from the roto rooter camera work. But I have been thinking of calling them again. Thanks!
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