Cut into a sewer inspection chamber?

13 Sep 2011
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United Kingdom
I have the downpipe from one side of my roof, which drops into the ground and drains water off into the gravel run of the main 4" sewer pipe from my house, at the moment it's all soil covered but I want to put a patio down on top, so thought I better properly sort out where the water goes rather than just having a soak away type affair which blocks up regularly.

There is a large inspection cover with 3 inlets coming in about 4-5 ft away from the downpipe, but no spare inlet in the chamber, the inspection chamber is about 3ft deep what I want to know is can I just cut a downpipe size hole into the side of the chamber about 1ft down and feed the downpipe into the side of the chamber? I assume I would need a u bend type of fixing at surface level to stop the smell of the drain coming up?

Not sure how else I get the surface water from the downpipe into the main sewer without having to replace the entire inspection chamber to enable more inlets??

Any ideas would be appreciated?
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Unless you have a combined rainwater/foul system ( which is very unlikely ) or a cesspool - you will be breaking the law :eek: The Sussex Rain Police will be after you :mrgreen:
As far as i know Nige F is right.....but, as an exercise is hypothetical thinking...

The chamber is likely to be 2 course of bricks thick which you would need to get through. The idea of a u bend would be more likely to cause a blockage in time from gutter debris. If the imaginery pipe was solid from the chamber to gutter level any smell would disapate at more or less stench pipe height would it not?

But of course, as the ever vidulant Sussex Rain Police are everywhere you wouldn't do it would you.... :eek:
the inspection chamber is one of those terracotta coloured plastic ones, with a metal cover. So cutting into it with a circular drill bit is easy enough, your right about the smell disapating, however I was gong to have the gutter drop into Aco channel drainage (1m lengths for 8m) which I was going to run along the length of the house, to take all the surface water off the patio as well.

The other option I have is to direct the rainwater with the channel drainage into the kitchen waste hopper? Which is about 2 metres away?
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Joking aside , the kitchen hopper is a better way to go - If you come to sell up and a survey finds an unusual connection into a plastic manhole , some jobsworth is bound to cause you grief then :idea: . Also the smell won`t dissipate , trust me I`m a plumber ;)
As Nige F says, that is a better idea altogether and less work i should think
Also the smell won`t dissipate , trust me I`m a plumber ;)

Just as an aside Nige, are you sure the smell at gutter level wouldn't dissipate, reason i ask, i was on a roof today and noticed the stench pipe quite near to where i was working, so remembering this post measured the height difference from the gutter to the top of the stench pipe....14" or 350mm in new money...

This was a street of houses all the same, council build in the 50's i should think...could that 14 inch make all the difference or is it that the pipe end is in free air allowing the smell to waft away more easily..?
I guess my answer was too brief ;) What I meant was the smell would appear @ the RW outlet in the gutter which might be near a window etc.

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