Lapping DPM and DPC for a concrete slab

[Simonharry]

Hi all,

 

Hopefully you can guide me here…

 

I’m trying to understand in which order I need to lap my dpm and dpc.

 

We are pouring the slab after the walls have been built so the bricklayer has laid a 600mm dpc on the internal skin which laps down the internal block work.

 

I am now prepping for the concrete slab and am keen to understand if the dpm laps under or over the 600mm dpm?

 

Apologies for the hideous attempt to draw what I think is the order of dpm / dpc’s.

 

Happy to be corrected.

 

Thanks

 

 

Edited May 23 by Simonharry
Picture added

[LD84]

Bumping this incase it hasn't been answered. Keen to understand the best method.

[Mike]

Either way is fine - there just needs to be a minimum 100mm overlap. And, in your sketch, it's the 'lower' DMP that's acting as the DPM; the polythene over the top of the insulation is a slip membrane to maintain separation between the insulation and the screed.