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Damp concrete slab in bathroom

14 years ago

In our guest bath, we had linoleum as the flooring. The floor around the toilet has always been a little darker than the rest of the floor, so we didn't think much of it, but then over the past few weeks we noticed that the darkness is spreading.

We pulled up the linoleum, and discovered that the floor underneath is damp. The bathtub is right next to the toilet, and we ran it and the shower for a while to see if it could be causing the leaking, but didn't see anything.

So, we're stumped as to what could be causing this. The dampness looks like it's spreading out from the toilet, but it's just wetness -- not excrement (so not like a failing wax ring or something). Any guesses on what could be causing this?

We've pulled out all the flooring and the toilet. If we let it dry completely, and then run the bathtub/shower for a long while, and no wetness appears, can we make a safe assumption that it is NOT related to the bathtub?

Also, who would we possibly call to help us troubleshoot this (and presumably fix it if there is a problem)? A plumber? Someone else?

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Comments (5)

lucy
14 years ago
Maybe the caulking job or the seal around the toilet is old and dried up?
mike_kaiser_gw
14 years ago
The floor around the toilet has always been a little darker than the rest of the floor, so we didn't think much of it, but then over the past few weeks we noticed that the darkness is spreading.

My first thought would be the wax ring under the toilet. Given it's a $1.50 fix, I'd try that first.

After that I'd look at the toilet water supply connection and the seal between the tank and the bowl.

If we let it dry completely, and then run the bathtub/shower for a long while,

Did you just run the shower/tub or actually have someone take a shower? Water splashing off the body can get out around the curtain/door while not when the water is just running.
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jsmith99702
14 years ago
How bad is it could it just be the sweat off the toilet?
rivkadr
Original Author
14 years ago
The head of the bathtub/shower is what is next to the toilet, and it's 7 foot wall. Water would have to take a large turn around the corner to get by the toilet, so that would have to some impressive shower splashing to get there! Our concern was more that maybe a pipe had broken underneath in the concrete slab -- is that possible, and if so, would it cause the dampness that we're seeing?

I do think the more likely explanation is the toilet, though, considering the pattern of the water in the linoleum (looks like it spread out from the base of the toilet). We've owned this house for 3 years -- the dark marks in the floor were there when we bought it, so obviously the toilet was leaking before we bought it. We actually had a new wax ring installed a year and a half ago, by a professional plumber, and yet in that time, there appears to still have been dampness issues. I would hope a plumber would be able to install a wax ring correctly! Does that suggest to you a problem with the toilet itself?

We were thinking of doing the following:

1) Having a plumber come in and look at the toilet flange and make sure it looks good, and if not, have him replace it. It actually looks kind of old and questionable to us, so it may be part of the problem.

2) We'll go ahead and install our new tile floor.

3) Buy a new toilet, just in case the problem was actually with the toilet itself (it was here when we bought the house; have no idea how old it is).

4) Have the plumber back out and install it, since I don't want to take any chances with this.

Thoughts?
hendricus
14 years ago
You can check the sweating problem yourself. Flush the toilet, take a good hot shower, wipe the outside of the toilet with some tissues or toilet paper and see how wet it can be.

We've had this with linoleum before, its just the toilet sweating.

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