Drains under a new patio

[dwall]

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• dwall
• 23 Sep 2013
• 1

In the above picture, I've taken up a old patio which covered an original path running along the back of the house. I've done this with a view to laying a new patio.


At first I thought that the 2 drains in red and the one in blue, which go down quite deep, all drained into a main drain under the manhole cover just visible at the far end of the picture. However the rainwater downpipe (nearest) appears to go to a soakaway.

Problem: The new finished patio height will be higher than before (but still 3 courses below DPC ). I want to use 2 new grates level with the patio surface (see pic below) so that the rainwater and kitchen sink pipes connect into them temporarily with a view to replacing guttering down pipes and sink pipe later. When I replace these pipes, it would then mean I don't need to go back underground. According to the manufacturer, the grate in the pic below has a 105mm exit spigot designed to feed into 110mm underground waste pipe.

Question : Is there a safe way of connecting the bottom exit of the new grate to the 68mm square fitting they've buried in the ground (rainwater soakaway) or the 100mm round soil pipe (kitchen waster) ?

If not, the belt and braces option is to take up the old pipes below the kitchen waste and redo with new pipe, p-trap etc and also take up path around the 68mm square pipe right back to where I can lay a new 110mm soil pipe into the mystery soakway... However, as it all works nicely now I'm just checking there is no way to connect this up without 'botching' it.

Thoughts welcomed?

Cheers
Dan

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• dwall
• 23 Sep 2013
• 1

 

[Hugh Jaleak]

Not sure what type of gulley you are looking at, but a new (Bottle?) gulley is straightforward to connect to 100mm pipework, various collars are available to make such a connection. Use 110mm plastic pipe and fittings to alter as required. Kitchen gulley will need a trap anyway as it's connecting to the sewer. Use of a bottle gulley may help as these contain an integral trap, simply connect outlet to existing sewer.

Rainwater (providing it goes to a soakaway) does not need a trap, however I would be extremely wary of reducing the pipe size underground as it may be a pinch point for blockages from leaf/moss debris from the roof. If replacing I would run it in 110mm all the way, you dont want to have to pull the new patio up to access a blocked pipe.... Gulley on a rainwater pipe also has benefit of catching any detritus before it gets into the drain/soakway.

 

[dwall]

Thank you for the quick response.

Yup, I think I'll replace the underground rainwater pipe with a proper brown colour 110mm soil pipe and hook it up to the new grate. I don't think the soakaway can be very far from the ground entry point of the rainwater square pipe. You can see the downpipe in the picky below (far left). There was no sign of it when digging out the foundation to the left of it for the wall and step and nothing out as far as the nearest pergola leg and staddle as that has a 2.5 foot deep concrete pile under it.

As for the kitchen pipe, I'll dig out the current square 150mm hopper and fix from the grate exit spigot to the 100mm pipe with a coupler. Thanks again for the advice and sanity check

Dan

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• dwall
• 24 Sep 2013
• 1