Improving thermal conductivity for concrete floor

[Jag-diynot]

Hello all,

I have bought the ground floor studio flat. There was really strong damp smell in the flat. The smell had penetrated everything, doors, plasterboards, old carpet, floor board and more. So I took everyting out and now I am rebuilding the flat (interior) from scratch. Good news all the smell has gone. The floorboards were rotten, under the floors there was water. The bathroom had leakages which were probably ignored for many years.

The floor had layer of clear plastic sheet on top of that 20mm "General Purpose Polystyrene", link below, and finished with 18mm chipboard flooring.
https://www.wickes.co.uk/Kay-Metzel...tyrene-EPS70---2400mm-x-600mm-x-25mm/p/210801

Now, I am planning to put the 1000 gauge Damp Proof Membrane and then the insulation board. At this moment I am struggling to find a better product that "General Purpose Polystyrene" for better thermal insulation.
Can I use "Iko Enertherm PIR Insulation Board 2400 X 1200 X 25mm" on the concrete floor? As this one has much better thermal conductivity.

https://www.wickes.co.uk/Iko-Enertherm-PIR-Insulation-Board-2400-X-1200-X-25mm/p/234897


PS: Just to add I have been told lower the thermal conductivity rating the better.
General Purpose Polystyrene - Thermal Conductivity: 0.038 W/mK
Iko Enertherm PIR Insulation - Thermal Conductivity: 0.022 W/mK

Regards
Jag

 

[Mr Chibs]

Yes, you can use these pir boards on the floor. Lob a dpm down first, then tape the joints with aluminium duct tape, try to get it nice and tight no gaps.

Then you can float the flooring of your choice.

I don’t think there is any better insulation than pir, when comparing thermal vs thickness.

Iko, Celotex and Eco-therm are similar boards.

 

[Jag-diynot]

Thank you for the reply Mr Chibs. That is interesting, if I understood correctly, on top of PIR insulation boards, I can lay the laminate flooring directly, instead of installing 18mm chipboard floor and then installing laminate floor on top of it. Is my understading correct?

 

[Mr Chibs]

For a thin floor, you’d be better with ply/chipboard underneath.

if you went engineered wooden, you can lay it straight on.

 

[Swwils]

You should also factor in that the thermal conductivity of materials is not a constant. PIR loses some effectiveness below 10C.