Fall on horizontal shower waste to boss strap

[john2k]

I’m connecting a 40mm shower waste into a vertical soil stack using a boss strap. The boss inlet will be side-entry (horizontal) into the stack and i have a rubber adaptor for the 40mm pipe to enter the boss inlet bit.

The distance from the shower tray outlet to the boss strap connection is roughly 70–80cm at most. The shower tray instructions state the waste pipe needs a minimum fall of 3cm per metre for proper drainage.

My plan was:
1. drop down vertically from the tray waste
2. then use an elbow and run straight into the boss strap.

But if I do that, the horizontal section into the boss is basically level (little/no fall).
Given the 3cm/m requirement, what’s the correct way to achieve the fall when the boss connection itself is horizontal?

Thank you

 

[denso13]

I’m connecting a 40mm shower waste into a vertical soil stack using a boss strap. The boss inlet will be side-entry (horizontal) into the stack and i have a rubber adaptor for the 40mm pipe to enter the boss inlet bit.

The distance from the shower tray outlet to the boss strap connection is roughly 70–80cm at most. The shower tray instructions state the waste pipe needs a minimum fall of 3cm per metre for proper drainage.

My plan was:
1. drop down vertically from the tray waste
2. then use an elbow and run straight into the boss strap.

But if I do that, the horizontal section into the boss is basically level (little/no fall).
Given the 3cm/m requirement, what’s the correct way to achieve the fall when the boss connection itself is horizontal?

Thank you

The boss connection isn't horizontal, it allows a connection at the correct fall, give or take.

 

[john2k]

The boss connection isn't horizontal, it allows a connection at the correct fall, give or take.

Really but visually looking at it when I clamp it to the vertical soil pipe, that entry port where the rubber gasket goes looks dead straight lol. So wondering how does the pipe that goes into it then bend to create a fall? Or will the rubber tolerate this? Worried that flexing it to make the fall may create a gap of some kind in the rubber

 

[denso13]

The rubber will accommodate it, just not too much.

 

[Madrab]

If you can avoid it, try not using the rubber adapters. Over the longer term they can become troublesome as they age harden. If at all possible I would recommend that you either use the correct pushfit or ideally a solvent weld adapter.