I've got a bathtub upstairs that won't drain (at all), and slowly fills with water apparently from fixtures in the same bath room and the adjacent bathroom.
Whatever is going on doesn't appear to be impacting any downstairs fixtures (sinks, toilet, washing machine). I tried to snake the bath but the snake stops advancing without being able to clear the clog. It brings back small clumps of hair. I called out a solid professional plumber, and he was also not able to either clear the clog or explain the backing up.
His recommendation was to begin cutting out ceiling downstairs to get into the pipe and figure out what was going on, but I wanted some other input before I embarked on something expensive.
Is it possible that a local clog at the tub could be causing the backup? I'm obviously not a plumber, but it seems like that would have to be somewhere in the pipes shared by the two bathrooms for water to come across from the other shower into this tub.
Best Answer
Based on your description and what you have snaked, it appears that the blockage is in the down-pipe between the first and 2nd floor. Water is traversing horizontal and able to back flow into the tub. I don’t know why the plumber didn’t do this, but if you can safely do this, look for the sewer vent pipes on the roof above the area where the blockage is. You should be able to snake from the vent pipe to the down pipe and clear the blockage.
Before doing the snake from the vent pipes on the roof, You might try the chemical method first, such as Drano Gel and Main Line Clearners. As always be careful while using the toxic chemicals.