Positioning of DPM for inner walls

[Gaf]

New build. Floor makeup from the architect's construction drawing is:

 

• Concrete screed with underfloor heating 75mm
• Kingspan Thermfloor TF70 125mm with perimeter strip 25mm
• Concrete subfloor (A 193mesh) with 50 mm cover 150mm
• Monarflex RMB 400 d.p.m. radon barrier acting also as d.p.m.
• 300mm compacted hardcore filling

 

Attached is a close-up of the DPM on the construction drawings for the inner block walls. I've added the red line just to highlight from my view of it that the DPM doesn't seem to have been shown 'continuing over' the blocks to create an unbroken layer (like the green line I added). Is that standard practice? Does the DPM just get 'stuck' onto the inner wall?

 

Then to add more to this. I got the attached photo showing the actual make-up of the floor. It looks like the DPM was put below the concrete subfloor instead of above it as outlined on the construction drawings. Does that matter? One thing that's bugging me on this is that a part of the floor (screed + insulation) had to come up to move a misplaced pipe. I noticed a piece of the DPM 'stick up' out of the concrete subfloor as if it wasn't 'attached' / flush against the wall below. Has me wondering how the DPM was laid.

 

We do have a surveyor inspecting each part of the build. He's on holidays and I can't get chatting to him for a while now. Regardless, I like to be informed on this stuff. Appreciate any steer on this.

[DevilDamo]

You would only have perimeter strip insulation against the external walls. The DPM would also only run up the external walls. The DPM would be continuous and therefore running under the block wall would be more practical.

[Gaf]

Thanks, you've just made me realise the architect's drawings have two different representations for the floor buildup. Their drawing shows the DPM between the subfloor and the insulation (red line), but their annotated text on the drawing places the DPM between the hardcore filling and the concrete subfloor (purple line). I thought the builder had placed it incorrectly but now realise he followed the annotated text and not the visual part of the drawing, so the DPM is probably in the right place and likely just runs along under the internal walls blocks exactly as you've said. Cheers.

Edited September 1 by Gaf