Installing a trapped gully with channel drainage (ACO hexdrain)

12 Jul 2019
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United Kingdom
First post - please be gentle!

I once had a trapped gully 20190625_072418058_iOS.jpg to take away kitchen wastewater but in installing a patio and channel drainage to serve a new extension the builders failed to reinstall a replacement trap. 20190629-_DSF8848.jpg The same white kitchen waste pipe is a useful reference point and you can see how the ACO drain has been installed beyond the corner of the house to the left of the downpipe to allow water to fall vertically untrapped into the original clay pipe.

I don't want kitchen sink waste spilling over the patio - and building control absolutely want a trap in place because this is a connection to a manhole serving a foul drain.

Here 20190625_121634228_iOS-2.jpg you can see (during demolition / excavation) the remnants of the old trapped gully under the pipe. The foul drain is on its left.

A P-trap gully could be installed off to the right of the kitchen waste pipe somewhere and under the ACO hexdrain using its vertical knockout. I could manage this myself - just! The problem is that the old clay pipe turns into a bend just 28cm under ground level so there is no room under the hexdrain to install a typical P-trap and bend to connect by this route.

It is however possible to make further deeper excavations to connect with the original clay pipe further along its run but this is beyond me & I'd have to get somebody in - is there an alternative to a typical P-trap gully which I could install and would work here?

Building control sign off on the whole extension build is held up by this one issue - any ideas would be appreciated.

Thanks, Scott

(PS I deducted an amount to fix this from the payment to the patio / drain installers who knew perfectly well from my specification that the drains had to pass building control. With a trap there before they started work I lazily assumed there would be one there afterwards!)


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Rather than the P-trap gully, Could you use a bottle Gully as it is smaller?

Thanks - that had been going through my head and you have made me look again. It could be installed more or less under the white waste pipe at the location of the old gully with the hexdrain connected flush into it at ground level - but looking at an example but I am not sure how the hexdrain (8cm deep) would be cut in and connected to it. It's width may also present a problem.

Alternatively, I think it could go under the hexdrain using its push out hole but the whole grid on top would probably have to be removed and again I am not sure about making a good connection.

Any thoughts on this connection issue would be appreciated. :confused:
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Thanks - that's another route to investigate. I may get a bottle gully into my hands (not exactly expensive) and on site I may be able to get a better picture of how it might be made to work. Or not! :D
Get one of this type of Bottle gulley, They are more expensive, (but needs must), that will give you the benefit of a boss connection on each side. Aco drain to 110mm connectors are available, basically an end cap for the Aco drain with a 110mm spigot on it, which will mate with the boss on the Bottle gulley to join the channel drain to the gulley.

Set Bottle Gulley in desired position to join up with Aco drain, suitable bends and required pipework can be used to join the outlet up with the clay spigot you've got left. Kitchen waste pipe then needs extending, (use bends as required), to discharge into the gulley, below the grid, but above the water level.

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