Recommended method for connecting 40/50mm wastes to a soil stack

[Annker]

I'm looking for some advice regarding connections soil stack.

 

I have an ensuite and bathroom located back to back and the plan is to connect all the wastes (2xWCs, 2x showers & 2x WHBs) into a single soil stack which is located on the other side of a wall these two wet rooms share.

 

The WCs will share a back to back concealed cistern ,the waste from this will push into 90 degree bend then a 1 metre horizontal run through the wall and then connect to the soil stack with a 90 branch.

 

My question is if there is a preferred method of connecting the shower and WHB wastes to the soil stack. 

 

A neat option could be to combine the 2x shower waste connections to the stack along with the WC connection with this triple socket 90 branch.

 

Or is it better to use strap bosses or even these McAlpine bosses and make individual connection to the stack?

 

Also are there rules concerning shower/WHB wastes connect to a soil stack above/below WC connection to the stack? 

 

[marmic]

i will be interested to see replies as we'll be doing something similar soon - eveything into one stack / drain.  A tip I've been given is to have a dedicated waste pipe from shower to avoid the trap being 'siphoned out'  and a lovely scent entering the bathroom!

[ProDave]

3 hours ago, Annker said:

The WCs will share a back to back concealed cistern ,the waste from this will push into 90 degree bend then a 1 metre horizontal run through the wall and then connect to the soil stack with a 90 branch.

I am keen to see how this back to back WC into a single outlet works, and does it suffer the "swapped contents" problem?

[G and J]

2 hours ago, ProDave said:

I am keen to see how this back to back WC into a single outlet works, and does it suffer the "swapped contents" problem?

Are you talking sh*t?   (Sorry, couldn’t resist that!)

[Annker]

@ProDave Hopefully the manufacturers have considered that but I guess only practical "testing" will confirm.

 

My initial plan was to run the horizontal soil from the frame at/above floor level; as opposed to below floor level within the joist void.

Therefore avoiding any rearrangement of the joist solid bridging.

 

However, from the image of the frame I noticed that the short vertical outlet attached to the frame appears longer than those on say Geberit frames.

Rather than assuming that vertical outlet could be cut back to permit running the horizontal pipe above floor level I decided to call the Vitra tech dept.

They didn't provide a definitive response but suggested that frame may benefit from the longer drop provided from that longer vertical outlet.

Its frustratingly all too common to hear manufactures giving ambiguous advice regarding how their products perform or should be installed. 

 

Edited 1 hour ago by Annker