100mm EPS70 at 3 sheets to the pack for £42 inc assuming you’re not too far from Birmingham. Ecclestones are a foam converter. 
 

https://ecclestons.com/xcart/sheet/eps70-polystyrene-sheet/polystyrene-eps70-sheet-12mm-to-300mm.html

 

For 225mm go with 3 layers at 75mm as it comes 4 to a pack and you will be easily sorted. 

1 hour ago, Russell griffiths said:

So I would look at this differently and do the lot in EPS buy it in bulk and save a fortune on PIR prices. 

Sell the pir or use it in the roof. 

 

Go to an eps manufacturer dont  buy it from a re seller, they will cut it to any thickness you want so you can tweak your finished floor height. 

 

 

Interesting take on things Russell. I'll definitely enquire with the manufacturer. But as I already have the PIR on site it may be easier to just add the 200mm EPS to the set-up.

 

Still the questions below if anyone has opinions thanks:

 

100mm screed - question... can I use a self levelling liquid screed at this thickness?

150 PIR insulation (already on site)

200 mm EPS insulation

 

Do you think the BCO will have a problem with this? If so why?

51 minutes ago, PeterW said:

100mm EPS70 at 3 sheets to the pack for £42 inc assuming you’re not too far from Birmingham. Ecclestones are a foam converter. 
 

https://ecclestons.com/xcart/sheet/eps70-polystyrene-sheet/polystyrene-eps70-sheet-12mm-to-300mm.html

 

For 225mm go with 3 layers at 75mm as it comes 4 to a pack and you will be easily sorted. 

Great info thanks very much Peter.

This forum is absolutely superb. As I improve I hope to contribute where I can.

Hi guys,

Can I get your opinions on this set-up with insulation in place and DPM and DPC locations?

All good, or any glaring errors.

Thanks very much.

 

Edited April 2, 20215 yr by Johnny Jekyll