Side Extension - Moving soil pipe

30 May 2021
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United Kingdom
It's a semi detached house with private man hole and drains. The soil pipe is on the side of the building and a new side extension is being built.

A new manhole is also being built to move the drains and then connect to main manhole.

But for the soil pipe, I think there won't be enough drop. Do we box it in within the new extension? Ideally I would want to avoid it.

Would like to know how this problem is generally addressed. I have attached a picture showing the pipes and the manhole.

Green colored is the existing pipework for the man hole. Red circle is where the new manhole is being built.



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No hard or fast rules on a way around it, all depends on whats already in the ground, levels etc, as to the best way to get around the issue. Options are, either box it in as is, or divert the pipe through/around the extension. Normally I'd expect the issue to be addressed in the plans, Building Inspector may want to look at any rerouted drainage.
Thanks Hugh, we are planning to go with the box it in option.

Anything to consider when we go with that option?
Is it a single storey or double height? If single storey then getting a good waterproof connection where it passes through the roof can be difficult especially when so close to the wall.
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Thanks Hugh, we are planning to go with the box it in option.

Anything to consider when we go with that option?

Only thing I'd add is replace it with plastic pipework if you weren't already going to do so. Waste pipes could possibly be connected, allowing removal of the Hopper, downpipe and associated gully.
Thanks again, we are replacing it with plastic pipework.

In an another forum someone mentioned, they moved the toilet to the rear wall in the first floor and moved the soil pipe to the rear as well. Which seemed like a good idea as well. But I won't be able to do it.

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