Groundwork & Foundations

How to go about removing concrete encased gully and pipe near foundations

Anonymous user 23/02/2024 - 2.45 PM

Hi, I'm currently part way into a backyard renovation which mainly revolves around installing a new patio to the rear of a ~1910 mid victorian terrace with rear access only through the house. I've removed the old slab layer (there were actually 2) as it was in poor condition and actually over the level of the DPC. Part of the job is replacing the existing mixed rainwater / waste gully as it's in poor condition and sitting too high (right up on the DPC). I thought this would be fairly straight forward however the entire gully and I believe the pipe connected to it is encased in a massive hunk of concrete. The pipe also travels down quite deep (what would have been about 1.5 metres from old surface level) within about 2 metres of the gully which I believe is because the manhole is only 5 metres away and is quite deep. Being an old property it has only shallow brick foundations and I'm a bit worried that removing this concrete could destabilise the foundations. How should I go about doing this to pose as little risk as possible to the house? -- Edit This job is now thankfully long since done! As Linken mentions below removing the concrete was not deemed a risk by the groundsmen I ended up hiring and was actually fairly easy to break up owing to a weak original mixture.