Installing an upstairs toilet - do I need a Saniflo???

[ItsTony]

In our warehouse, we would like to install a totally new toilet upstairs. Currently, there is a sink for the kitchen upstairs which goes around the room until it is above the downstairs toilet and then just goes straight down and cuts into the fat sewage pipe from the toilet. What I want to ask is if I wanted to install a toilet upstairs, could I simply replace the thin wastage pipe going downstairs and install a fat wastage pipe along with a toilet upstairs, considering I already have a water supply on a flexi-pipe or will I need to install a Saniflo to help pump it down.

Thanx

[dickymint]

A Saniflo cistern has a smaller diameter pipe because it macerates your turds/paper thus allowing it to be pumped through a smaller pipe. Why can't you fit a standard 4" pipe?

[ItsTony]

Is a 4 inch pipe a standard wastage pipe for a toilet. If so, would I just replace the other thin wastage pipe and have it going straight down from upstairs to downstairs.

Another stupid question but could the other wastage pipe from the sink join onto a pipe that is flushing crap, or will it flow back up this pipe and come out of the sink.

Thanks

[B17NNS]

Assuming you can get a sufficent fall from a 4" waste there is no need for a Saniflow. I'd try and avoid wherever possible to be honest.

Yes you can connect a 32mm or 40mm waste from a wash hand basin directly to a 4" waste using one of these http://www.screwfix.com/prods/81605/Plumbing/Soil-... and one of these http://www.screwfix.com/prods/41571/Plumbing/Soil-...

Simply core drill the top of the 4" waste and attach. The waste pipe from the sink is just a push fit into the adaptor.

The stack will need to be properly vented either through the roof or by using an air admittance valve at a point higher than the sink.

To do the job properly Building Control will need to be informed so they can inspect the work at various stages. They are usually very helpful chaps who want they same thing you do - a proper job done. Their fee structure is also very reasonable.

[silverthorn2151]

From what you have said there should be no need for a saniflo. They are really intended for situations where there is really no other way of making a drainage connection.

What you will need to do is form the 102mm vertical stack, connecting into the horizontal one at ground floor. Bring that up vertical above the new wc and, as described above, eiother vent it or have an air admittance valve. Where I would differ is that I would suggest connecting the sink waste at first floor into the side of the 102mm stack rather than the top (if I have read the previous post correctly).

There are some other specific requirements you need to take into account when doing this, but the Building Control officer will guide you.

Don't forget your new wc will need ventilation.