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outofplumb · Jan 28, 2009, 06:39 AM

This is my third post about my slow draining bathtub dilemma... this time I have a diagram!

Its pretty self explanatory. I just installed the vent near the tub, but it didn't help very much, still slow drainage/backing up into the tub, although it drains well for the first bit of water.

A few notes: I'm in Canada, and below 0 weather with lots of snow, so this may be responsible for main vent stack clogging if that's suspected.

Before I installed the new vent near the tub, there was gurgling in the tub drain when running lots of water in the sink. i.e. acting as a vent.

I'm looking for advice as to the best way to solve this drainage issue. Thanks

EDIT: I might add that I have also recently snaked the entire length of the pipe up to the main stack, and found no clog as far as I could tell.

Milo Dolezal · Jan 28, 2009, 07:24 AM

If the sink backs up into the tub - but toilet drains OK - than it means, as you correctly suspect, you have drain obstruction somewhere between sink drain and main stack.

Is this a new drain installation (tub, sink) or existing ? Are you on slab or raised foundation ?

outofplumb · Jan 28, 2009, 07:32 AM

Originally Posted by Milo Dolezal

If the sink backs up into the tub - but toilet drains ok - than it means, as you correctly suspect, you have drain obstruction somewhere between sink drain and main stack.

Is this a new drain installation (tub, sink) or existing ? Are you on slab or raised foundation ?

Its an older installation. Its all copper piping. But the fixtures are new.
It's a raised foundation. This washroom is on the 2nd floor though.

I swear I snaked it! I guess ill try again... but is it possible that the main stack is clogged somehow? By ice or snow maybe? There is a short bend in the stack in the attic before it goes out the roof, where stuff might collect. On the other hand, it's a 4" cast iron stack (so very large, hard to clog).

Milo Dolezal · Jan 28, 2009, 07:40 AM

How did you figured out the drain layout as presented in your drawing ?
What size of snake did you use ?

Yes, there is always a possibility that main stack may be frozen. But that said, you would have problems with other fixtures as well. How is the toilet flushing ? Are other fixtures working OK ?

outofplumb · Jan 28, 2009, 07:47 AM

Originally Posted by Milo Dolezal

How did you figured out the drain layout as presented in your drawing ?
What size of snake did you use ?

Yes, there is always a possibility that main stack may be frozen. But that said, you would have problems with other fixtures as well. How is the toilet flushing ? Are other fixtures working OK ?

I redid the floor, so I saw the piping. The snake I'm using is pretty light duty... its about 12' long and with a corkscrew that's maybe 1.5" long.

the toilet drains fine, but its also like 1 foot away from the stack and has a 4" pipe, so its pretty hard to stop it! The other (1st floor) washroom joins up to the stack in the basement, and it drains fine. That's all there is on the stack.

Milo Dolezal · Jan 28, 2009, 07:55 AM

At which point do you insert the snake ? What's the size of the tub/drain drains ? What material are your drains ? (Cast Iron, Galvanized, Plastic.. )

You should use 3/8 snake and at 25' long.

It happens quite often during remodeling that once you start replacing plumbing fixtures, you have to cut / shorten old drain. Or you tap them, bang them... During the process of working with the drain, sediment inside the drain gets loose, travels and encloses drain usually in bends. It has to be snaked and make sure snake clears all fittings, including the ones that connects into 4" stack.

outofplumb · Jan 28, 2009, 08:05 AM

Originally Posted by Milo Dolezal

At which point do you insert the snake ? What's the size of the tub/drain drains ? What material are your drains ? (Cast Iron, Galvanized, Plastic..)

You should use 3/8 snake and at 25' long.

It happens quite often during remodeling that once you start replacing plumbing fixtures, you have to cut / shorten old drain. Or you tap them, bang them.... During the process of working with the drain, sediment inside the drain gets loose, travels and encloses drain usually in bends. It has to be snaked and make sure snake clears all fittings, including the ones that connects into 4" stack.

I snaked from both tub overflow and sink. I plan to snake again from the sink towards the stack... maybe its clogged at the stack entry.

Everything is 1.5" copper, except i think part of the last run of pipe nearest the stack may be 1.5" or 2" cast iron.

whats a "3/8 snake"? oh 3/8", I think that's what I got

Milo Dolezal · Jan 28, 2009, 08:13 AM

Check the connection where copper and cast iron drains connect. Also, you cannot snake well through tub overflow opening. I don't believe you went all 15' of snake through tub overflow. But if you used all 15' after all than - according to your sketch - you probably didn't reach the transition to the 4" pipe anyway.

Btw: 1 1/2" drain for tub is too small.

3/8" is a size / thickness of snake. You can rent one from HD.

outofplumb · Jan 28, 2009, 09:32 AM

Originally Posted by Milo Dolezal

Check the connection where copper and cast iron drains connect. Also, you cannot snake well through tub overflow opening. I don't believe you went all 15' of snake through tub overflow. But if you used all 15' afterall than - according to your sketch - you probably didn't reach the transition to the 4" pipe anyway.

Btw: 1 1/2" drain for tub is too small.

3/8" is a size / thickness of snake. You can rent one from HD.

Thanks for the help Milo. I just finished snaking again and this time I really cranked it, and...
My bathtub now drains like a dream! The new vent really helps to speed it up I think, because its now faster than before the reno.

As far as I can tell it was just buildup in the old pipe that made the opening to the stack too small, and cranking it with the snake opened it up.

Finally I can take a shower!

Milo Dolezal · Jan 28, 2009, 09:08 PM

Originally Posted by outofplumb

thanks for the help Milo. I just finished snaking again and this time i really cranked it, and...
my bathtub now drains like a dream! the new vent really helps to speed it up i think, because its now faster than before the reno.

as far as I can tell it was just buildup in the old pipe that made the opening to the stack too small, and cranking it with the snake opened it up.

finally i can take a shower!

Great ! Congratulations ! I think you didn't reach the stack fitting with your snake first time.

Glad to be of help... Milo