Long Horizontal Drain Run

[Bodmin]

Hi - new to this forum and hoping for some advice regarding drainage.

I'm planning on fitting a kitchen in a separate part of my house so my daughter can in effect have her own flat. Unfortunately the room in question is quite a long way from the drain stack.

I see two options - saniflo or long horizontal drain. My preference is to avoid a saniflo.

The question is - can I run a horizontal 40mm drain around two walls of an adjacent room? The pipe would be hidden behind the plasterboard, run for approx. 4m, turn 90 deg, run for another 4m then connect into a vertical drain stack. Will this work with an Air Admitance Valve close to the kitchen sink? (obviously when I say horizontal pipe run it will have a fall towards the drain stack).

Thanks in advance to anyone who can assist with my question.

 

[snowhead]

Too long for 40mm (using the manufacturers guidance)
Increase it to 50mm from the 90 deg bend, including the bend.

Make sure you can rod it from both ends.

 

[Darren Jackson]

As Snowhead suggests above, I would also run 50mm waste from the stack to the kitchen reducing it to 40mm at the kitchen sink trap or the "T" if any other outlets are required for washing machine or dishwasher etc..

 

[Chuck]

I'm planning on fitting a kitchen in a separate part of my house so my daughter can in effect have her own flat.

Make sure you investigate the planning permission, building regs compliance and council tax implications of your idea before going too far.

 

[townfanjon]

nothing wrong with Saniflows mate

 

[JCplumb]

The maximum for a 50mm waste run is 4m.
Your situation is 8m with a bend in the middle.
The official answer's no. However, I've seen worse that has worked fine. As above, just make sure you have rodding points.