tap into stink pipe on pot drains

[ThreeSheets]

I have an old ground floor loo where the soil pipe goes vertically through the bathroom concrete floor and into the drains. Just to one side of this (outside) is the vent pipe. Can I replace the vent pipe with a plastic one and then tee into it from the new loo? Or are some old fittings that the vent pipe fits into not capable of taking soil?
Many thanks

 

[cmother1]

Hard to say without doing a test on the drains to see that the joints are OK. Also take a look in your manhole to make sure that only one pipe comes in from the toilet/vent direction. Sometimes the vent comes in separately half way up the manhole wall, in which case it would be unsuitable for connecting another WC.
Ask around your neighbours to see if anyone has successfully done something similar.

 

[ThreeSheets]

There is only one gully that runs through the bottom of the first manhole, which happens to be a 90deg bend to run down the side of the property.

I don't suspect that the drains are not sound, it was more a question about the design or types of fitting that the vent pipe was inserted into.

I have removed the cast iron vent pipe, buckets of water go down OK.

The reason I need to do this is that exit from the traps of new WC's are all desiged to go out through the wall rather than underground, in any case I have to reposition the WC in the bathroom.

Neighbours are a bit geriatric, most properties are ripe for development. DIY is taking your own wheelie bin out.

Thank you for your reply

 

[dextrous]

Ideally you should block up the pipe and test it (airtest of you have a manomenter, or fill up the pipe with water and see if it drops).

However, sounds like the design you suggest is ok, but remember to add the vent pipe back on.

 

[cmother1]

Threesheets - your last post implied that you are replacing your existing WC rather than adding another. Personally I'd try to keep the work indoors. These days there's a huge selection of pan connectors and other fittings to help you do this. If you've a clay pipe coming straight out of the sub-floor it can be carefully cut off below floor level and adapted with one of these: http://www.angelplastics.co.uk/Images/Products/XAC400.jpg. I did this when I moved our pan 30" to one side a few years ago and have never had a problem with it. Make sure you build in a rodding point, just in case.

 

[JohnD]

the soil pipe goes vertically through the bathroom concrete floor

Pig of a job to cut that off below the floor.

 

[ThreeSheets]

Or are some old fittings that the vent pipe fits into not capable of taking soil?

Given that the pipe is sound [all soil is going the same route at the moment, albeit 18" to the left] the question is - are the proerties of the underground bit that a CI vent fits into always suitable to route soil down, or are [1950's] there some which are as a vent only? It isn't the pipe I am worried about, it's just the internal design of the part the vent terminates in, if you see what I mean.
Many thanks

 

[dextrous]

The vent branch will be just an underground tee, nothing more complicated than that.

 

[ThreeSheets]

The vent branch will be just an underground tee, nothing more complicated than that.

Dextrous
So it should be OK to route soil down it from the WC?
Regards

 

[dextrous]

The vent branch will be just an underground tee, nothing more complicated than that.

Dextrous
So it should be OK to route soil down it from the WC?
Regards

If the current WC and the vent pipe run through the same outlet within the manhole, then this should be fine - although if you can test it for leaks as I suggested earlier, then so much the better

 

[cmother1]

Sorry all - my last post here was complete b*llocks thanks to me not reading the OP properly. Just head for the great outdoors ThreeSheets....

 

[ThreeSheets]

Sorry all - my last post here was complete b*llocks thanks to me not reading the OP properly. Just head for the great outdoors ThreeSheets....

No worries.
It's good of posters to take te time to anwer.
Many thanks.