Floor prep in kitchen extension

[bassmonster]

Hi all,
I'd really appreciate and advice.

To cut a long story short, a close friend of mine has been left high and dry by a builder in the tune of 130k with work of appalling quality and incomplete.

We just found that the electrical work has to be redone again as its not safe whatsoever.

When I enquired with my mate if building regs (not local authority) have been around to check the new kitchen extension, he said that builder has said it's been taken care of. Bearing in mind that the floor has now had underfloor heating installed and tiled. Having my doubts, I said the he should check with the building regs himself. After he called, he was advised that only the foundation was checked and no other site visits were made since. So, my mate subimitted photos of the floor prep and has been told that it's not correct. He wasn't told what exactly the problem is but will discuss when they meet. He's obviously very distraught as he's got no funds left.

I've attached photos which were submitted to the inspector.

Thank you for feedback as to what seems to be incorrect.

 

[^woody^]

Insulation not thick enough.

Not enough cement with the sand to make it into concrete.

Looks like it may need to come up if that's the case.

 

[bassmonster]

As far as I understand, the bottom photo has 100mm insulation, then they concreted it then damp proof, (black material) and then 50mm insulation was laid for underfloor heating.
the photo is showing the sand only and not concrete mix.

so in total, there's 150mm insulation.

 

[^woody^]

That's an odd floor construction.

That sand piled up like that is concerning and it shouldn't be there in any case.