Underground drainage plans for building regs

[John Williamson]

About to submit some drainage plans to building regs so I was hoping that the wonderful people on here would give some views on what they would likely object to as it's easier to make changes before submitting than after.

Assuming the gradients are within spec does anything look out of place or could be simplified here? The shower/sink waste goes into a gully because I can't get the 450mm above the invert of the soil pipe to connect a boss to. Everything else in terms of inspection chambers etc is my interpretation of the regs so I'm sure I will have slipped up on something.

Waste at the very old property has been tested to confirm it is combined waste so I'm mixing surface and foul here. The pipe which runs under the building is an existing clay one and I've had a camera down it which showed no cracks or blockages.

Any advice much appreciated

 

[ShaunCorbs]

They may want your rain and drain separate just warning you

 

[John Williamson]

They may want your rain and drain separate just warning you

Thanks Shaun. Fully prepared to have that discussion. What I think I have on my side is that:

• As an 18th Century Listed Building adding a further drain under the property could risk the structural integrity of the building
• The waste as it currently stands is combined and other parts of the drainage system already connect to the foul waste
• The current arrangement discharges directly on to the pavement which would create a risk for the public in cold months

Having said that I'm fully at the mercy of the inspector on the day. Let's just hope they are pragmatic