I live in a 140 year old house. As usual, plumbing is a conglomeration of materials. I have been hearing dripping through the kitchen wall when water drains from the second floor bathroom. There is a false wall behind the kitchen cabinets and dishwasher. The drain line and water lines run through that space. From just under the second floor the drain vent stack is cast iron. It has a "Y" fitting under the floor and copper line from the fixtures in the bath. At the bottom of the cast "Y" fitting there is a Plastic fitting. The plastic pipe below it goes up inside the plastic fitting. It appears that the joint is leaking where the pipe goes up inside the plastic fitting. This is positioned in such a way that I can't sees how the fitting can be easily replaced. Is there a way of repairing a vertical leak?

"At the bottom of the cast "Y" fitting there is a Plastic fitting. The plastic pipe below it goes up inside the plastic fitting. It appears that the joint is leaking where the pipe goes up inside the plastic fitting."

You're going to hafta give us more details then just that. What fitting? What pipe? If this a PVC to PVC leak dry the joint off with a hairdryer and paint the joi\nt with PVC primer. Then take PVC glue and fill the joint up. Let it set up for 4 hours and don't drain any water past the joint. Good luck, Tom

Cameroon,
If you look at my tips you will see that answering questions by PM or E-mail puts me at a hardship. Your post was deleted by my E-mail filter. Please repost,and this time post on the plumbing site. Thank you , tom

I had opened the second story floor a bit to get a view of where the leak was occurring and the leak was just below the first floor ceiling. I opened a hole in the space between the top of my kitchen cabinets and the ceiling. There was no way replacement was going to be easy. I tried something which is working and I hope will continue to do so. Reaching through the hole in the kitchen wall, I wiped off the area around the leaking joint and then rubbed it with sandpaper to make sure it was clean. I then hit the same area with PVC primer. I then painted multiple coats of LIQUID TAPE (I guess this is plastisol) around the entire pipe, below, at and above the leaking joint. This made a rubbery coating that seems to have adhered well to the pipe. So far so good. I don't care if it's conventional, as long as it works. By taking out the dishwasher I was able to see that this dripping leak had already rotted away some of the plywood sub-floor below the leak. I'm wondering if I should be misting the area with Clorox or something to kill off any fungus or mold that may exist. I removed all the wood that was soft and soggy.

Congratulations! You followed my suggestion about grouting the leak with PVC Cement or Another sealant, (liquid Tape). As rhis is a drainage bleak and not a pressure one that should solve your problem. Good luck, tom

Thanks for taking an interest Luckily all the pressurized pipes in that space are sweated copper.