DPM first or insulation?

[noseall]

depends on the insulation. only require above with some.

I think you are correct.

I think it mainly applies mainly to 'jablite' i.e. polystyrene.

 

[bigshineybike]

I'm facing the dilemma, most of my house was extended around 1996, it's 100mm polystyrene on compacted soil a pale blue heavy DPM and 80mm concrete on top.
I have found a little mouse nest in the polystyrene .
The newer part of the house is 2010, 100mm celotex and 80mm concrete both on top of black DPM, thinner grade but doubled up.
Both seems to have lasted.
With my latest addition.
I've got some pipework to work around so it's easier to fill the celotex around the awkward bits then DPM over . Finally fill it with concrete.

 

[Deluks]

I'm facing the dilemma

Please start a new thread.

Also, what's the dilemma here?

 

[Diver Fred]

This is how they like it in Staffs, one under the inso' and one over.

That is how it was done on the last 2 sites I have been on.

Wacked Hardcore, 25mm soft sand, DPC, Insulation , 2nd DPC, min of 75mm Concrete (either reinforcing mesh or UFH pipes). New building in close to my house had 200mm of insulation in the floor! regularly see 100 or 150mm of underfloor insulation.