My mum has a duplex in Montreal, Quebec. The downstairs bathroom ceiling drywall is always decaying and I know why. The upstairs tenant has a "sweating" toilet above causing that and a few years ago I insulated that water closet using a rigid foam that was glued in. That toilet still "sweats". Re-grouting the floor tile around the toilet may only solve a tiny part of the moisture problem. What can I do to control this sweating
Answer:
You can replace only the water closet on the toilet with one that has a "check drip" liner in it and that helps a lot. At the cottage I got around it by installing an old, nude hot water tank without electricity so there is always a 40-gallon reserve at ambient temperature and the sweating doesn't take place.
