Lots of drainage going to one Soil Stack

[daveybdab]

Hi there.

I am redoing my kithchin and bathroom in my flat. The bathroom is right next to the the back wall where there is the main soil stack and the kitchen is right next to the bathroom. The toilet will be connect dirrectly to soil stack and is located right next to it. I also need to connect the bath, basin, kitchen sink dishwasher and washing machine to the soil stak. How would i best do this. If I had 1 pipe connected to the soil stack for everything except the toilet what diameter/gradient would this need to be to provide the required flow rate? Or would I be better off having two separate connections to the soil stack, one for bathrrom, one for kitchen - it might be difficult to get all the connections into the S/S.

Any advice would be appreciated.

 

[DeltaT2]

Perhaps a wee sketch would help alleviate your fears David son. Stick up a sketch & we'll help further.

 

[daveybdab]

Thanks for the reply delta.

I have attached a little sketch showing the proposed arrangement. Hope this makes it a bit more clear.

Untitled

• daveybdab
• 12 Sep 2011
• 1

 

[DeltaT2]

Not a problem with this. Run a 110mm horizontal soil pipe from the external SVP, right into the corner at the D/W & have a small stub stack up to just under worktop height. Form a bulkhead behind the WC & a full bulkhead at the base/top of the bath, these will accomodate the soil pipe & other pipes. Tee of for the WC/bath/basin/sink/DW & WM.........Job Done!!

 

[daveybdab]

cheers delta. With a 110mm diameter pipe could i connect the toilet into it at the end or does the toilet need a separate connection to the main soil stack. also what sort of fall would i need on the 110mm pipe?

 

[DeltaT2]

cheers delta. With a 110mm diameter pipe could i connect the toilet into it at the end or does the toilet need a separate connection to the main soil stack. also what sort of fall would i need on the 110mm pipe?

Yup, as I said just fit a tee/branch on the horizontal 110mm pipe to pick up the WC.

About 1 in 40 gradient = 25mm/Meter = 1.5deg would be fine.

Strictly speaking all waste pipes should go into a vertical soil pipe (eg stub stack or external SVP) - for correct 'Single Stack' soil pipe design. So you would need to get the horizontal soil pipe as low as poss. Or run the bath waste pipe, which would be the lowest waste pipe, out & connect to the external SVP, then it would be fitted below the horizontal soil pipe internally.
Maximum waste pipe lengths 40mm/3M & 32mm/1.7M.
Clear as mud eh??!!..........

 

[DeltaT2]

Oh, just another wee thought, if you're having an integral dish washer, they're a complete 'James Hunt' to get pipes behind!! It would be much better if the dishwasher was sited at the left side of the sink & all hoses from the dishwasher connected under the sink, well, in the sink base unit.
Hope that's been helpfull.