Connecting Shower and Utility Basin to Soil Stack – Advice Needed

[LouDIYtryer]

I’m planning some waste pipe work and could use some advice. The setup will be:

• Shower waste to connect into a utility basin waste.
• Basin waste then runs into the soil stack.

The actual basin-to-soil stack connection seems straightforward (maybe?)

I was thinking of using something like this flexible pan connector with a pipe boss: https://www.toolstation.com/viva-90-flexible-pan-connector-inc-pipe-boss/p44790


For the shower-to-basin link, can I use a boss lower down the pipe. The soil stack is already at ground level, so once we raise the floor, that section will end up underground.


Questions:

• Is this approach sound for connecting shower → basin → soil stack?
• Any tips on boss positioning and pipe fall?
• Do I need separate traps for the shower and basin, or can one trap work?
• Anything I should watch out for with venting or smells?

Thanks for any advice!

Please ignore the washing machine pipe coming through the wall that was just temporary
Also, please ignore all the wood lying around – we’re building the framework for the toilet. It’s only been like this for about 7 years! We always said a downstairs toilet would be ideal for the new baby… who is turning 5 in two weeks.

 

[denso13]

I was thinking of using something like this flexible pan connector with a pipe boss: https://www.toolstation.com/viva-90-flexible-pan-connector-inc-pipe-boss/p44790

That'll be far too high for a shower. Better connecting the basin and shower separately to the drainage system.

 

[Madrab]

+1

Given the shower is the lowest point, anything higher connected into the same run, if the shared pipe blocks, will run into the shower tray and then overflow quite quickly.

As suggested, ideally you would want them on separate runs, if that isn't possible then connect the basin as far down the run towards the stack as possible. if you are talking about using the soil connection for the toilet then the basin could be connected into a boss on a pan connector as that's high enough but you will be left with an exposed waste run.

As suggested, the shower will need to connect into the stack much lower down.

 

[Hugh Jaleak]

All Appliances require their own Trap, if the pipework is going to be buried/concealed, then use Solvent Weld waste and test for leaks before covering.

Shower, keep run as straight as possible, look at a Shower Trap with removable insert to allow access for cleaning the downstream waste run from the tray, and if the Utility room sink/basin joins the run, I'd upsize to 50mm waste at that point. An Antivac trap on the sink and basin wouldn't be a bad idea either, given it all looks like it's directly connecting to the drain.