Waste to soil stack, horizontal or vertical run?

[bobsyeruncle]

This probably sound more complicated than it is lol.

In the new upstairs bathroom, the soil stack runs horizontal through the eaves for about 2m before it turns 90degrees through the soffit and directly down to the drain.

Can I add the boss connection for the shower along the horizontal length inside the eaves of the house or does it have to be in the vertical length outside the house?

I also have the condensate pipe from the boiler to add in somewhere as well.

Many Thanks

 

[polesapart]

Best practise is to run to the vertical soil pipe.

Surely the height of the shower trap outlet and the need for a 1:40 slope
would preclude bossing onto the "horizontal" soil branch anyway?

 

[denso13]

Either way is ok. Does the horizontal bit have any slope on it or is it level?

 

[Richardthe3rd]

Either way is ok. Does the horizontal bit have any slope on it or is it level?

Wrong!! In a single stack SVP system all waste pipes should enter a vertical stack. With a 40mm waste pipe limited to a maximum length of 3 meters.

 

[bobsyeruncle]

The horizontal run is sloped, don't know the exact ratio but it's more than enough.

The waste pipe will have to travel for more than 3m to get to the soil pipe in the vertical run, it would barely make a connection to the horizontal run within 3m, will that be a problem?