What kind of concrete mix to put back after laying new pipework?

[pieceofmind]

The old pipes were under the floorboards, wrapped in a kind of 'wool felt' and loosely/partially buried in a fairly crumbly brittle 'concrete' (for want of a better word), which chiselled away easily with an SDS drill. Now I've laid the new pipes I need to replace the concrete. Any idea what it is or where to get it? I've still got the crumbled up remnant of what I chiselled out. Maybe I could mix that with something and put it back?

 

[denso13]

Now I've laid the new pipes I need to replace the concrete.

Do you need to if it is below floorboards? Will it be seen at all?

 

[pieceofmind]

I guess not, but I assume it was there for a reason in the first place?

 

[ianmcd]

I guess not, but I assume it was there for a reason in the first place?

not really just the way things were done, hairfelt on pipes on the ground and crap piling up over time , best way to do it is properly insulate and clip to underside of joists, but it has been on the ground all these years so just properly insulating will be OK

 

[pieceofmind]

Thank you.