DIY Downstairs toilet

[angliojoe]

Hello All,

I've used this forum a lot over the last few weeks since buying my first house and its been loads of help but this is my first question i've posted.

I would like to install a downstairs toilet and basin under the stairs. The problem is that currently there is no water supply, no window and waste pipe to that room so I'm starting from scratch

I love DIY and want to tackle this but have a few problems i cant get round.

Firstly, how can I fit an extractor fan (as there is no window) if this is a mid terrace? Would I have to run a air duct from the new toilet to the outside through the kitchen? surely there is an easier way?

Secondly, Do I just run the waste from the back of the toilet and basin under the floor and outside to meet the waste pipe from the upstairs toilet? Would I need some sort of pump as it will take a good 4/5 meters of horizontal pipe before it reaches the outside?

Sorry for all the questions, as you can guess I am not a plumber but I did fit my own bathroom so figured this could be a progression

Thanks all,

Joe.

 

[stem]

Hello angliojoe and welcome to the forum

The fan must vent outside, so it's a matter of finding the best route, only you know the exact layout of your house. Mine does sound similar and the duct runs between the joists above the ground floor ceiling to the nearest outside wall. If that's not possible, go vertically and box in the duct in a corner of an upstairs room, or if you can, run it through a built in wardrobe, or airing cupboard into the loft to vent outside via a stack, soffit or apex wall?

Untitled

• stem
• 22 Sep 2010
• 6

Untitled

• stem
• 22 Sep 2010
• 4

If it's a long run you will need a powerful fan to overcome the pressure loss in the duct. A centrifugal inline fan would be best. Don't use a standard axial fan, they won't produce enough pressure to get the air through a long duct.

With regard to the loo, that's not my area of expertise, however I believe horizontal runs are OK, but I believe that they must have a drop of something like 1 in 40? Otherwise you can use a combined macerator and pump. Saniflo seem to be the most common. (Other makes are available ) They discharge via a small bore pipe. Because of the pump the pipe can go vertically and horizontally. You can also connect the sink waste to the same unit. They tend to be disliked though, because they have to be emptied manually when they fail and they don't work in a power cut.

 

[angliojoe]

Wow, thanks for the thorough response. That's everything I need. Really appreciate it thanks.

Joe.

 

[OwainDIYer]

you may be able to drop the extractor fan duct downwards and run below the ground floor level (if you have suspended ground floor).

You can get small (2-3kW) instant electric handwash heaters which saves running hot water.

 

[Hugh Jaleak]

Put considering a Saniflo in the same league as considering boiling your own head. If you cant get a 4" drain to it then I really would forget the idea now, apparently there are some football matches on TV at the minute so I would suggest you watch those instead?

4" (110mm) pipe is fine over a large distance, provided you keep a constant fall over the length of the run. Dips and bends are a big NO, you need to keep a straight run from the WC position to the existing drain. All drain runs also need to be accessible for maintenance, I would expect to see the new drain connect to the existing drain either at an existing manhole or by the building of a new manhole at the point of connection, thereby allowing rodding access up the run towards the new pan.

Any further questions, feel free to ask.

 

[stem]

You can get small (2-3kW) instant electric handwash heaters which saves running hot water.

That's not a bad idea. In most of these type of installations the water from the domestic hot water system hasn't started running hot by the time you've finished washing your hands. You will of course have to run a suitable electrical supply instead, and some feel they are not aesthetically pleasing.

Put considering a Saniflo in the same league as considering boiling your own head

Told you they weren't liked