Why on earth does my vent pipe leak. It is properly vented through the roof. the leak is just below the tub and toilet subfloor. it is just above the T where the bathroom drain pipe and main vent stack meet. If the bathroom drain pipe was clogged I would be experienccing slow drains or backups, which I am not. It leaks after someone uses the tub/shower. So how could the vent pipe above the T be filling up with water? please help.
What kind of pipe is it. You said it only leaks when tub shower are used, is it bad , is it steady, its probly comming from leak in tile wall are pipe to tub and shower might be leaking, you could test pipe by putting test ball in test tee and filling with water and see if pipe is broke are where leak is comming from. Do you have seoerate Shower and tub, if so take 5 Gal. bucket of water and dump in each one at a time and see if it leaks, if it doesnt then it is something with wall. Do one and let it drain and check then do other one.