What do I use to fill this?

[horwich]

Hi

I need to fill these "trenches" that I dug out for moving the kitchen? What materials are to be used here in UK? I was expecting concrete with a top finish cement/fine arids top layer, but from what I removed, it is the same material top to bottom.

For background, I'm Spanish, and I am not familiar with the techniques nor materials here.

Thanks in advance for your help.

 

[pcaouolte]

Which part do you want to fill? Red, Blue or Green?

 

[horwich]

Good point!!! I feel embarrased now.

It is the blue bit.

 

[Wayners]

Line trench with plastic. Buy bags of concrete mix. Add water and pour in.
Sponge and polish top smooth as you can.

Would the plastic get punctured? Anything sharp in trench? Use sand to smooth out before plastic

 

[robinbanks]

If that's a screed on top of insulation, don't concrete all the way up to the wall; leave a fillet of insulation isolating the thermal connection. It looks to be under the kitchen cabinets anyway?

 

[Wayners]

I was wondering if it should have some floor insulation?
Did you remove any?