Accessing Existing Underfloor Waste Pipe

[drewks]

Hello!
I'm shortly going to be fitting a shower in an existing downstairs cloakroom which has a wc and sink.
The wc waste disappears down directly behind the wc and I'm assuming the basin waste ('imperial' 32mm!) empties into the same waste as they are both in line.
I'd be grateful for some help/advice with the following (again assuming that I've got a clay 4" waste pipe under the solid floor....house built 1975):

1) Is it likely to be a clay pipe and how do I best excavate and find it without smashing it to pieces?!

2) The only reason I'm asking (1) is I'm assuming I must discharge the new shower waste directly into this waste pipe - there IS no outside wall etc I could use. I'm presuming there's no way I can discharge the larger shower waste into the smaller (existing) basin waste before it goes underground?

3) What would the best way - & best products - be for connecting new shower and basin wastes into the existing waste pipe in this case?

Phew, that's it! Thanks for reading, and as said I'd be very grateful for any suggestions or help.

 

[Hugh Jaleak]

1. Very carefully!

2. 32mm probably too small, you'll find the water backs up into the shower tray.

3. Depends on how existing waste is connected. You may be lucky and find a plastic adaptor has been used, in which case you may be able to alter it to accept a 40mm pipe for the shower and tee 32mm basin waste into that, or if its Hepsleve pipe then a suitable adaptor is easy enough to obtain. Difficult to say for certain until you can expose whats already there.

 

[drewks]

Thanks Huge (love the name!!).
So basically it's 'softly softly' with the chisel & bolster till I see what's what.
Bugger - thought there may have been a better way......oh well!

 

[Hugh Jaleak]

Clayware is like any earthenware product, it'll break very easily. The newer vitrified clay pipes are fragile, the old salt glazed stuff is even worse... I'd work well away from the pipe, until you've ascertained what is there. Crack the pipe lengthways and the whole section will need to come out.....

How is the existing pan connected? May be an alternative depending on room available, look at McAlpine's site. Various option available for adding a waste via a pan connector, but with a shower as always its getting the fall on the waste....