vapour barrier - solid floor

[kudos1uk]

I had building control out today to inspect my foundations which were passed.

Next is the slab, I had intended:

150mm hardcore > sand blinding > membrane > 100mm Kingspan > 100mm concrete slab.

The BCO said vapour barrier between the kingspan and slab.

Is this normal? im guessing it should be the same as the membrane (1000g) and lapping into the DPC with membrane?

 

[freddiemercurystwin]

It can be a 500 gauge membrane, its there to prevent concrete seeping into the gaps between the insulation as m,much as a vapour barrier.

 

[kudos1uk]

It can be a 500 gauge membrane, its there to prevent concrete seeping into the gaps between the insulation as m,much as a vapour barrier.

Ah I'm with you, to stop Thermal bridging.

 

[freddiemercurystwin]

Err well the thermal bridging would be minimal if even measurable, though it can tend to push the boards apart if they’re poorly fitted. Just good practice really.