Polished concrete floor build up - concrete sub slab needed?

[luz624]

Hello, we are planning for a polished concrete floor. I had a question as to whether the subfloor slab is required or not, as we'll already be laying 100mm of concrete at the top... 

 

• 100mm polished concrete (poured over UFH pipes)
• Vapour control layer
• 200mm EPS insulation
• DPM
• 100mm concrete subfloor slab --> Do we need this? If we are pouring concrete as the final layer, is the subslab needed?
• Hardcore

 

 

[markc]

There was a similar thread last week regarding this.

I personally can’t see the point in double slabs if the ground is good and compacted hardcore is there.

bbut if I remember correctly one or moreBCO’s had wanted the sub slab

[luz624]

Thanks @markc -  that's useful to validate my thinking. I've pinged our BCO to get their view too.