Mid-terrace garden with shallow waste pipe - Help with solution

[rjsido]

Hi,

I am in the process of renovating my mid-terrace back garden/yard. A previous owner had put paving up to the level of the dpc and after removing this layer it exposed a shallow waste pipe (~150-200mm below the level of the dpc) and a drainage gully/hopper?? attached to a downpipe from guttering (~100mm below dpc level). There is also a manhole currently with cover at the level of the dpc. I have submitted some pictures on imgur showing the current situation (hopefully you will be able to view these).

Pictures showing situation

I am unsure as to what to do going forward and would appreciate some advice regarding drainage. Would one of the workarounds listed in the dpc part of the pavingexpert website be a suitable solution? My only concern is the bricks below the dpc appear damaged where there was a concrete edging (see pics). Currently there is no significant problem with damp and I was originally planning to put a gravel path along the side of the house (just at a lower level).

Thanks for the website and book (very helpful)

Rob

[Tony McC]

It seems to me that the concrete/mortar fillet against the bwk is set at, or damned close to, the DPC, so your paving needs to be 150mm below that.

The hoppers seems to be set at the correct level, although the IC cover is too high, but could probably be reduced by removing a course or two of that regulating bwk.

The one pipe I can see is, as you say, shallow, but it looks as though you should just about be able to get some paving over it.....depending on just what type of paving you are considering.

[rjsido]

Thanks. I was planning on putting cellular paving with a gravel fill along there. Would you excavate a bit further down either side of the shallow waste pipe for a sub-base level?

[Tony McC]

You could dig down around the pipe, but I'd surround it with either pipe bedding/pea gravel or haunch it with concrete, rather than cover a bare pipe with a larger aggregate. You need something that will act as a 'cushion' and so protect the pipe.