Improve ground floor thermal conductivity. Screed or subfloor?

[Jonny Vee]

I`m doing a bit or renovation and I have 100mm of concrete sitting directly on soil. Removing it to poor a proper concrete and then 200mm insulation would have a massive cost impact and this is not feasible.

I was thinking to poor 30mm or screed to level up all ground floor and then 18mm floor board with 3mm underlay.

I was also checking if can use some very thin PIR insulation 12.5mm and then plywood and finish level with 18mm floor board and underlay.

What would be the best option?

 

[motorbiking]

12.5mm insulation wont make any difference. Does this work need building control?

 

[Jonny Vee]

12.5mm insulation wont make any difference. Does this work need building control?

Nope. I did not touch the existing floor. Just removed the old dirty carpet and some old T & G board.

 

[motorbiking]

what about a floating floor - that would give you 40mm? that would make a difference. Floor boards would have to be bonded.

 

[Jonny Vee]

what about a floating floor - that would give you 40mm? that would make a difference. Floor boards would have to be bonded.

Floating floor on uneven substrate? I have some place where is 35mm and others where is 40/45. Substrate is not nice and flat