Soil Stacks and Connections

[Victorian House]

Hi, I've been reading a lot about drainage connections and wondering if anyone can clear up a few things. I've sketched out the bathroom and utility plan below. Basic plan is:​ Foul stack coming from WC/Shower room overhead run internally in a large wall​ Connect ground floor into the stack - WC, basin, utility sink, freestanding bath​ Connect washing machine, dryer into utility sink above trap​ Stack exits wall to chamber outside​ ​ Would you see any problems with this layout?​ Would there be any risk of upstairs causing issues downstairs, e.g. blockages?​ Drain for freestanding bath - would 50mm run without venting work at 2m run? Thanks! ​

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[Ben-gee]

That’ll be fine, presuming there is a nice slow bend at the bottom of the stack- which there probably is.

 

[exedon2]

Only issue may connecting bath waste to stack correctly.
What's floor construction?

 

[oz-plumber]

Why don't you just run 1 drain from the stack to the WC and connect the 2 sinks into that drain?
3 separate drains not necessary and a lot of extra work for the same outcome.

Bath waste will have to be on its own drain, due to height issues, but no vent needed over that distance

 

[Victorian House]

Thanks for all the comments!

Only issue may connecting bath waste to stack correctly.
What's floor construction?

Floor construction is stone/tile floor on UFH in screed (65mm) over insulation (140mm) over concrete slab (150mm). I thought the bath connection could possibly be to the stack below the WC connection. WC connection would be run over the floor in a concealed wall system.

Why don't you just run 1 drain from the stack to the WC and connect the 2 sinks into that drain?
3 separate drains not necessary and a lot of extra work for the same outcome.

I was thinking something along the line of this (from marley brochure) - with the sinks coming in high and the WC in above floor level.

and then a connection like this for the freestanding bath - under the WC:

The bend out from the stack to the drain is under an old wall - so the more I can connect into the stack, the less support work I need to do under the wall.