Advice on drains, manhole and waste pipes.

[luz624]

Hello,

 

We are struggling to get a plumber secured at the moment so wanted to ask a few things just to help ensure we're on the right track. 

 

We are building a side return extension. There is currently an existing manhole in the side return. We plan to move this to the courtyard area shown in the proposed diagrams. The builders have done the hardcore and DPM and close to pouring the concrete sub slab. Can anyone help advise: 

- What basic work is involved in moving the manhole (the manhole is just for our house). We believe the pipes for the existing manhole run in a straight line to where the new manhole will go. Do we need to do anything with the existing manhole before we build over it? 

- Can waste pipes from the kitchen and downstairs bathroom area go above the sub slab? i..e either through or above the insulation (where the UFH pipes will be)? is there any issue with this?