replacing low level wc Drainage and wastage systems and plumbing help, advice and answers

[frank pope]

I have a small cloakroom with low level WC. I am replacing this with a back to wall unit. The soil pipe goes directly into the concrete floor in brown plastic and there is a join some 30cm down, but the outlet is too far forward. I need to move the floor outlet back in order to accommodate the new WC. Is there a below ground flexi available or is there some other way to overcome the problem (offsets etc). Placing the WC in the existing position would make the room too small and the WC would be too close to a radiator on the side wall.

[thedoctor]

Unless you have the plumbing skills required Frank its not a good idea to go moving the pipe in the floor. The standard answer to this problem is to build a small box which you fit on the wall behind the new cistern to a) fill the gap and b) fix the new cistern to. The box is usually about 200mm thick and can be tiled when its fitted. It can be made out of cheap, sawn timber batten and covered in plasterboard when its on the wall. Paint the plasterboard with 2 coats of PVA adhesive (see our project on PVA using the link above) then tiled.

[frank pope]

As I indicated the solution you suggest is not feasible because the cloakroom is too restricted to sacrifice so much space behind the toilet. My best mate is a very good plumber and would guide me accordingly, and has suggested that Roca and Duravit can supply a pan with the soil pipe set back into the pan strcture, so I intend to investigate that possibilty first. I have tackled central heating and bathrroms but I am not enthusiastic about hammering through the foundation to move the soil pipe four inches, to be left with damp course repairs. I will keep you informed and thank you so much for your early and very sensible response.
frank.