Concrete for slab

[jayc89]

Our slab will be the finished floor so I plan to prep the area; insulation, UFH pipes and then get someone else in to pour it.

 

We’ve had someone quote to use “10mm aggregate flowing concrete” but I was expecting the quote to include the compressive strength of the concrete (C30 etc)

 

Is this normal? 

[markc]

Yes quite normal, if the concrete is over insulation and UFH then compressive strength of the concrete is meaningless

[JohnMo]

Depends on the floor buildup.  Don't your architect or structural engineering drawings specify what it should be.  Ours was reinforced C34 above sand blinding, then 200mm of insulation, then bonded cement screed.  But no one was supplying during lockdown, near us, so we used more C34 as that was readily available and were using it at the same time for structural pads to hold our roof down.