Drainage advice for extension

[Hugh Jaleak]

10mm over that distance is negligible, but it is vital the pipework is laid to a constant fall over the entire length. I would be looking to use a 5 inlet version and bring the 3 laterals in separately, if it's not feasible to achieve the angles with one chamber, either fit a second for the kitchen run, or look at building a chamber to incorporate the 3 inlets. Bigger preformed chambers are available if needed, 315mm dia Level Inlet Chamber Base 4 side Inlet (110mm) - www.drainageshop.co.uk although at 600mm invert depth, a smaller chamber wont hurt.

None of the connections can be left blind, you will need access to rod/jet upstream if a blockage ever occurs.

 

[Phillip Stephens]

Thanks Hugh. I’m looking at the Osma 315 multi base IC. It has 2 entries at 45 and 90 and one main channel so 4 opening in all. The plan would be to run laterals out - kitchen and wc to the 45 and 90 and the new wc at one end of the main channel with flow down and the remaining main channel would feed the lot back into the main run.

 

[^woody^]

Are you drawing up the plans for this extension yourself?

 

[Phillip Stephens]

The plans will be drawn by an architect and will eventually go to full plans approval. I’m just looking at the best way to lay things out as I’d rather not rely on an architect’s drainage drawings without him having the full picture

 

[^woody^]

The plans will be drawn by an architect and will eventually go to full plans approval. I’m just looking at the best way to lay things out as I’d rather not rely on an architect’s drainage drawings without him having the full picture

But that's his job. He should know about drainage and you as a client must be able to rely on his design. If you don't think that you can, you need to find someone else.

If a client was to tell me how to design drainage, I'd be telling him thay if he knew so much of my job he can draw the rest of the extension too.