Rear-outlet toilet: leak or condensation?

Hi,

I have an old floor mounted rear flush toilet that seems to have water collecting under it. In the past, when our septic has backed up, I have noticed water leaking from under the toilet which I put down to a bad seal. However, we have recently had our septic updated so I don't think it is backing up and causing a leak. Also, we have not used this toilet in a couple of days yet there seems to be a small amount of water collecting under it. I can tell by sliding a piece of paper under it and it comes out wet. Could the water come from sweating? The toilet is located in our basement and there is no heating/cooling in that room. The last few days we have had very cool nights (low 50s) but warm days (high 70s/low 80s). Could this be making the toilet sweat from underneath?

Thanks

Toilet sweating is almost always caused by the toilet leaking water from the tank into the bowl and down the drain. Dye test the toiet by putting some food coloring in the tank to see if it leaks into the bowl without flushing the toilet.

If the sweating is not visible on the tank and sides of the bowl and trapway, and the dye test is negatve then the toiet probably needs to be reset.

So I think that the problem is a bad seal between the toilet and the wall flange which will require changing and reseating. I have read in these forums that I should use a neoprene gasket but the only one I have found online is a Zurn neo-seal. I cannot see any information about the size of the neoprene gasket and I also don't know if the outlet on the toilet is 3'' or 4'' (nor the flange for that matter) without taking it off the wall. The PVC pipe coming off the flange is 3'' so I am assuming that the flange would be too, and presumably the outlet of the toilet is 3'' also. It is an old American Standard I think. Would I be able to reuse the gasket that is already there, assuming that it is neoprene and not wax? If so, is there some sort of glue or sealing compund that I would use to seal it? Does any one know the size of the Zurn Neo-seal?

thanks

I am still a little confused with what is happening with my basement toilet. I ahd planned to go ahead and reset the toilet with a new seal but never actually got around to doing it. Then all of a sudden, the moisture problem appeared to go away and it was dry for over a month, even with heavy use over a two week period from visiting relatives. However, it seems like the moisture is back again.

I tried the dye test and it does not seem to be leaking, and I'm pretty certain our septic is working fine so its not because of a back up. The only reasonable conclusion I can make is that it is caused by condensation under the toilet bowl/trap (the toilet has a "skirt" that lifts the bottom of the bowl a good inch or two off the floor). This appears to coincide with a drop in temperature at night (30-40s) and mild daytime temperatures (60s). Toilet feels very cold to the touch and the bathroom is not heated. Does this sound likely? Any ideas how to solve it?

Thanks