Crushed concrete or crushed Granite Type 1

[Steted21]

Evening All,

Im about to lay 150mm of hardcore for our extension floor base and have been asked if I need Crushed concrete Type 1 or Crushed Granite Type 1, this is then to have a sand binding over the top before dpm and concrete oversite is poured. Which one is the one to use or are both suitable?

Thanks in advance

 

[Deleted member 292770]

concrete. and for blinding i’d use 6mm to dust or dust . sand is too fine.
What about insulation?

 

[Steted21]

The plans state 150mm sand blinded hardcore, dpm then 100mm concrete, dpm 100mm Insulation underfloor heating pipes and then screed

 

[^woody^]

Can you be assured that the crushed concrete is not contaminated? If so it will be OK

Blinding should always be sand - building or similar loamy sand, not sharp.

 

[Deleted member 292770]

Building sand will clump up when compacted.