Waste configuration for several items

[NotAgainFFS]

Good evening!

I'd be very grateful of some advice please.

I am renovating a flat and need to move the waste pipe, running it from the kitchen, across the hall, through the bathroom, and out the brick wall to connect it to the waste/rainwater pipe which is 110mm black PVC pipe.

This will carry waste water from the dishwasher, washing machine, a shower (fed from a combi boiler) and the bathroom basin.

I suspect that this is quite a load on a single pipe, which has a run from end to end of about 4m. There is a good drop, however, and the pipe will be able to be run between the joists.

My initial thoughts were to run a 50mm pipe and connect the dishwasher and washing machine at one end, then tee the shower into the 50mm pipe close to its trap using a swept tee, and then add the wash hand basin near the other end of the pipe just before it leaves the building.

Does this make sense? Are there any potential problems? Do I need any anti-siphon valves in-line?

Thank you.

 

[Richardthe3rd]

For single stack UPVC soil pipe & waste systems you can't do what you propose. Each appliance must connect separately directly to the SVP(soil vent pipe), with the following maximum length;
40mm pipe = 3meters
36mm pipe = 1.5meters

If you don't follow this guide then you'll pull air into the traps & break the water seal.

You could extend the SVP & fit a stub stack.
HTH

 

[NotAgainFFS]

For single stack UPVC soil pipe & waste systems you can't do what you propose. Each appliance must connect separately directly to the SVP(soil vent pipe), with the following maximum length;
40mm pipe = 3meters
36mm pipe = 1.5meters

If you don't follow this guide then you'll pull air into the traps & break the water seal.

You could extend the SVP & fit a stub stack.
HTH

Thanks for your swift reply!

Here's some more info. This is a 1930s tenement building. Before I started ripping it apart the kitchen appliances and sink waste all travelled through the same 40mm pipe into the waste/rainwater pipe at the back of the flat. The bathroom wash hand basin and the shower used the same 40mm pipe into the waste/rainwater pipe at the front of the flat. The kitchen floor is a concrete slab. The external pipes are very close to the windows. Too close to extend the stack, it seems to me.

Any other thoughts? If I move in any direction here I seem to have the same problem.

The soil pipe is a separate stack, cast iron, and embedded into the brick and plasterwork. Nothing is connected to it except the WC pan.

 

[Richardthe3rd]

Ah, with combined a rainwater/waste pipe & separate soil pipe you have a two pipe system.

The abject of all these systems is to ensure you have 'air behind water', therefore, the length of run of any waste pipe is minimised.
Perhaps a rough sketch of your flat would help, any chance you could post up a sketch big chap?

 

[NotAgainFFS]

Thank you once again!

Sketch will be posted here shortly.

 

[NotAgainFFS]

(not to scale)

View media item 73606

 

[Richardthe3rd]

Thank you once again!

Sketch will be posted here shortly.

Sorry NAF, I've consumed my bottle of Buckie & now retiring for the evening, however, I shall give your sketch a quick once-over in the morning. Thanks for your gratitude.

 

[NotAgainFFS]

Thank you once again!

Sketch will be posted here shortly.

Sorry NAF, I've consumed my bottle of Buckie & now retiring for the evening, however, I shall give your sketch a quick once-over in the morning. Thanks for your gratitude.

Haha!

I hope your glass bottle of Irn Bru is chilling nicely for the morning

 

[Richardthe3rd]

Yes NAF it has pride of place in my Smeg & life wouldn't be the same without the Cumbernauld ginger refreshment.

Now, as for your waste pipe arrangement; yes, I'd opt for the 50mm pipe & connect as you have stated. The fear is always 'pulling' the seal on the shower trap, which can be as shallow as an SNP promise. If you fit anti-vac traps on both the wash basin & washing machine, then it'll be fine.
Of course you'll be fitting one of the extensive range of quality traps manufactured by McAlpine, made here in Scotland........

Thanks NAF for the concise & informative details. I hope your project goes well & I can look forward to receiving the invitation to the House Warming party, where copious amounts of Buckie, skunk & charlie will be on offer???

 

[jeff the gasman]

You can do what you asked if you use hepvo instead of traps.

 

[NotAgainFFS]

Indeed! Just deciding where the buckfast tap will be fitted and ramping up the growth lamps especially!

Thanks gents. Much appreciated!

 

[Richardthe3rd]

You can do what you asked if you use hepvo instead of traps.

Hepvo Durex traps are rubbish, they choke too easily. Much better with McAlpine.

 

[Richardthe3rd]

Indeed! Just deciding where the buckfast tap will be fitted and ramping up the growth lamps especially!

Thanks gents. Much appreciated!

Sounds good!! I'll get my string vent dry cleaned directly......