attaching drain to a vent stack

[Tamar]

Having the typical problem of water running back into the bathroom via the extractor fan. the soffits are not readily accessible. So, is it possible to run the water collected into the vent stack? or is this a complete no no? I do also plan to insulate the vent pipe going from the extractor fan, up to the ceiling. Flat is on the first floor, is a top floor flat. ta.

 

[Tamar]

Sorry. That's the water collected from a condensation trap, which would be fitted in the extractor fan vent pipe.

 

[catlad]

If you do that you will have a foul smelling bathroom.

 

[Tamar]

Do you mind explaining why.
There is a 4 ", coming straight up from the flat below.
the2" Drains and toilet connect into it.
the 4 " vent pipe goes straight up from there, through the ceiling and then only goes about 10" into the loft area, which vents into the loft space (no noticible smell at the moment.
How would a trickle of water going into the top cause a smell in the bathroom?
Just trying to get my head around it, as my builder had suggested this would be OK.

Ta

 

[catlad]

I have never heard of a vent pipe terminating in an attic space before, I work on roofs mainly and that is were they normally terminate, you smell them before you notice them.

 

[tony1851]

I have never heard of a vent pipe terminating in an attic space before, I work on roofs mainly and that is were they normally terminate, you smell them before you notice them.

Catlad; you can terminate a S&VP in a roof space if you fit it with an air-admittance valve. This allows air to be drawn INTO the pipe in the loft space (eg when suction is caused by flushing) but will not let foul air OUT into the loft space.
I agree that the OP should not connect the pipe into the soil pipe as it will cause smells in the bathroom.

 

[cajar]

Tamar, you would have to fit a trap otherwise you'd get air coming straight up from the sewer entering your bathroom.

 

[Tamar]

Ok, I see; and I'm guessing that the drain from the condensation trap is too narrow, and/or that you can't have water running through it. We may have to drain it through the ceiling, into the bath!!!

 

[Tamar]

tony, yes my hubby did not to tell me that there is a valve on top of the stack, until after my query went up. so I believe it is as you say, and takes air in to ease the drainage down below. Thanks for your post.