Advice on plumbing in shower waste at low level

[Matthew Clay]

Hey Guys!

First post so please go gentle.

I have recently moved into a property needing some medium/heavy cosmetic work and I am a very keen DIY'er, will get my hands dirty on any job. I just need a little guidance.

I want to add a shower to the ground floor WC. I am fairly comfortable with the whole install but i'm a little stumped on the waste.

This is the layout I want to achieve:

WC_Layout

• Matthew Clay
• 3 Jun 2019

This is the layout i want.
The shower is small (700x700) but only used as a secondary.

The shower is only going to be a 700x700 but i need to run the waste to the soil stack which is only 1.8m away..... but how do i connect it.

This is the side wall where the waste would most likely run:

WC Left Side Wall

• Matthew Clay
• 3 Jun 2019

1: Gas Pipe
2: Mains Water Supply
3: Soil Stack

Here you see, 1 is a mains gas pipe, 2, is the mains water supply, and 3 is the soil stack.
Sounds straightforward but the connector on the soil stack sits way too high:

WC Soil Stack

• Matthew Clay
• 3 Jun 2019

Connector sat at 15cm in height.

I dont really want to sit the shower off the floor by 20-30cm, how do i get that waste pipe to run nicely???

 

[Ian H]

Is the floor solid or suspended?

Looking at the pan connector at ground level I would say it’s clay pipe below so you will have to either dig a bit or lift a few floorboards to add a connection for your shower.

 

[Matthew Clay]

Is the floor solid or suspended?

Yeah, its a solid floor unfortunately. It's a 1970 build so likely to be clay or some other nice asbestos'y type material.

 

[undertrained]

Is there any way of running outside to a gulley?

 

[Matthew Clay]

Is there any way of running outside to a gulley?

I could but it would be a 4 meter run and would prefer the waste to not be visible. Ideally, run into the soil stack.
I have researched to see the pumped waste modules, maybe this could work and i connect to the stack.

 

[undertrained]

If you have the room, one of these may work: https://hertsplumbingsupplies.co.uk...P2Jhd5Rr-_NRXYWm9DRvn0k8x0k89VV4aAjz8EALw_wcB

 

[Matthew Clay]

That is no different to what I have already but the boss connector sits too high - unless you mean dig up floor and connect it below ground?

 

[undertrained]

It's completely different. What I mean is where the multi kwik is (the white connection) replace with this and you should get your height.

 

[Hugh Jaleak]

What is the gate valve in the floor connected to? The McAlpine connector would do the job, but you may have to cut the stack above the branch, and rejoin with a slip connector to graft that connector in. Not ideal, but infinitely better than digging the floor up.

 

[Matthew Clay]

What is the gate valve in the floor connected to? The McAlpine connector would do the job, but you may have to cut the stack above the branch, and rejoin with a slip connector to graft that connector in. Not ideal, but infinitely better than digging the floor up.

Pretty sure thats the rad drain off valve - its no longer operable since i had the CH system redone.
So I am guessing id need to raise the shower tray up to like 100-150mm to counter for the drop?

 

[Hugh Jaleak]

Yes, build a decent plinth to sit the tray on, can soon disguise it with tiles or floorcovering. Get the height of the outlet from your shower trap, work out your fall on the waste pipe and that will determine the height of the plinth.

 

[Matthew Clay]

how about this? https://www.ebay.co.uk/itm/263736022899

has anyone used a pump?? i could connect it to the existing boss joint. the unit could be boxed in with the waste pipes and soil stack.

 

[Hugh Jaleak]

You can, but they are noisy, and cheap versions may not last very long. Then you have the issue of getting power to it. For what little you'd gain, bite the bullet, fit the McAlpine connector, and run a gravity waste. You'd still need to raise the tray up to get a trap underneath if connecting to the pump unit.