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.

  • What type of drain stopper do you have, is it the one with the lever on the side, or is it a pop-up at the drain? How far were you able to snake? Commented Apr 17, 2020 at 14:29
  • if the snake brings back clumps of hair, then keep at it with the snake ... you may break through the blockage .... also, try snaking from the other fixtures that flood the tub
    – jsotola
    Commented Apr 18, 2020 at 3:10
  • @jsotola great tip on the other fixtures, thanks.
    – menacingly
    Commented Apr 18, 2020 at 19:49
  • @Programmer66 pop up at the drain, the snake gets about 5-7 feet in. I say 5-7 because I thought mine got 5 and the plumber said 7
    – menacingly
    Commented Apr 18, 2020 at 19:50

3 Answers 3


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.

  • This seems sensible, and makes a lot of sense. Do you happen to know the best way to identify which vent? I think there are two per bathroom, is one going to be more of a straight shot to the drain line than the others?
    – menacingly
    Commented Apr 20, 2020 at 1:46
  • If there are two, if one is larger in diameter, 4", that is the most likely be the one to connect to the main line going down. Also the one closest to the toilet. But try the chemical first, it may dissolve the blockage, save you form going up on the roof. Commented Apr 20, 2020 at 2:07

I will give you a plastic pipe suggestion as this chemical will damage metal drains. Since you and a plumber have tried snake without luck I would find a product called mule kick. This stuff is nasty and although will work with metal pipes it can damage metal. Mule kick will not harm plastic pipes and it will eat through almost any clog but kids plastic toys that may have been flushed, However it will dissolve the plug around the toy or this is what I found and we finally got the drain flowing and brought up a toy we think our oldest grandson flushed. Stopping 2 of 3 bathrooms and the kitchen.

I would not consider this stuff environmentally friendly but it worked when multiple power snakes failed. Much cheaper than guessing where the plug is and opening walls and lines full of poop.


I agree with the others, but some pointers may be useful. The clog could be further down than you think or could be related to venting from other fixtures. All drains, in both baths, should be snaked clear while running or pouring hot water into the drain and then tested in full by at least a couple of gallons of water to drain.

Snaking a drain dry or without a water load behind it will almost never clear a clog. And, any tub should only ever be snaked through its overflow and never through its drain. Meaning, there's absolutely no reason for a far reaching or properly run snake to fail in any Soft Clog situation.

However, a Hard Clog like a bracelet could be in there and flipping or a toy may stopping the snake, these would require invasive actions. But very typically, anything that fits down a tub or sink drain is always able to be pushed into the toilet's much bigger pipe that they connect to.

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