Installing new WC - concrete floor

[mallangong1]

Hi,

We have bought a new house and my other half is very keen to have a WC under the stairs. However the floor is concrete, so would it be acceptable to chase out a trench for the required waste pipe and then concrete back over?

Ta.

 

[Hugh Jaleak]

Concrete as in a solid floor or the concrete screed over a beam and block floor?

Solid floor shouldnt be too much of a problem provided damp proof membrane is maintained in the floor. If its beam and block then is going to be more tricky as you'll need to break through between the beams, and then it'll be a struggle to get access to the void under the floor to run the drain.

 

[ivixor]

Acceptable to who?

Sounds like a nightmare job to do. Install a saniflo instead.

 

[mallangong1]

Hugh, I'm not sure but assume solid as the house was built in 1920.

ivixor - Saniflo would seem to make sense however I have hear so many worrying stories about it.

 

[Hugh Jaleak]

Think you can safely assume solid floor in property of that era. Is there an outside wall available in the room where you wish to site the new W.C. ?

 

[mallangong1]

It would be a run of about 3m to the outside wall.

 

[Hugh Jaleak]

Any possibility of running a 4" pipe with requisite wall, to the outside? Digging up the floor for that length of run would be a bit of a mission..... I'd try and avoid the Saniflo route if at all possible, they're very selective on what they'll handle, and sorting one out when (not if!) it's jammed up and/or malfunctioned is not a pleasant prospect....

 

[mallangong1]

Given the incline needed on the waste pipe I can't see it helping as I would have to chase out the floor anyway to get the required incline.

 

[Hugh Jaleak]

Looks like you're between a rock and a hard place then... Not impossible to get a drain under the floor but will be a lot of work. Plus point is fit once and forget, (assuming done properly!).

Saniflo is other (easier?) option, but if you do choose this route, bear in mind the Saniflo wont handle anything that hasn't been through you first....

 

[Aligas]

Take a look at the grundfos macerator as an alternative to the saniflos, solo lift I think they're called. Different mechanism for grinding up the undesirables, easy to service/maintain as can be done with all sanitary ware in situ (depending on install). Uses a grinder rather than a blender-style blade so, according to manufacturer, they can deal with much heftier waste products....