Soil stack help

[RAW85]

Got a soil stack renewal for new loft extension. The customer is having two bathrooms with a toilet either side of the soil stack.
One exits the house 2 metres (roughly) to the left of the stack, the other 1 metre to the right.
Can I use two single wc branches one directly on top of the other, with the left hand side toilet with the longer fall on the bottom branch. Or just order up a double branch and have them entering the stack at the some point?

Cheers
RAW

 

[ShaunCorbs]

never have two pipes entering on the same level (either side) you can get cross flow and yes use two t branches, remember you need a decent fall tho (not level)

 

[village idiot]

Whatever you do, do not get them to enter the stack at the same point

 

[RAW85]

Cheers I thought as much...why do they sell double branches

 

[kozak1968]

As you say, fit one branch above the other, you don't want any come backs.

 

[village idiot]

Cheers I thought as much...why do they sell double branches ��

Because your toilet may be on the right, or the left. So you have options🙂

 

[kozak1968]

Rainwater stack possibly

 

[RAW85]

Thanks again gents!

 

[joni os]

Double branch, Osma 4S230, or similar. Radius overcomes problem of cross flow provided it is used in a vertical stack.

 

[ShaunCorbs]

Double branch, Osma 4S230, or similar. Radius overcomes problem of cross flow provided it is used in a vertical stack.

will still cross in either types

 

[Destroyer2813]

will still cross in either types

Not with one 1m one side and 2m the other way by the time you have it angled up from the branch

 

[turnpin]

Not with one 1m one side and 2m the other way by the time you have it angled up from the branch

+1 odds of both wc's flushed at exactly the same time over ridden by distance of pans from stack if correctly vented.....regards Turnpin:yes:

 

[ShaunCorbs]

+1 odds of both wc's flushed at exactly the same time over ridden by distance of pans from stack if correctly vented.....regards Turnpin:yes:

no but could happen so not impossible