Replacement Solid Floor Insulation Options

[anorakdiyer71]

House renovation with new extension
New Floor / oversight on new extended room
Replacement floor on existing part of house , with new oversight /membrane. Floor being hacked up

Underfloor heating within new screed on all ground floor on one level

Assuming Finished floor levels are correct and thought about, it would help if thinner insulation's used on the existing house.

As opposed to 100mm or 120mm celotex are there thinner alternatives that give simular U values??

It would be good if I could use 75mm or even 50mm would be helpful ??

 

[23vc]

Doubt you’d get away with much less than 100mm PIR if you’re doing it to building regs

 

[Pulp]

Did mine last year when had the extension, took up existing floor in kitchen and it had to be 100mm of celotex, that was under former building regs, might be even more now new regs apply.

 

[anorakdiyer71]

Thanks for your replies
But isn’t there insulation that is more compact that has better u value rating.??
Therefore 75mm of it would equal your standard 100mm cellotex rating.
This is the specific question I’m asking ?

 

[mikeey84]

Aerogel is supposed to offer better performance than celotex or similar, so can be used thinner. However,
A) it's incredibly expensive
B)not sure it's suitable for floors
C)there is some scepticism as to how much better it actually is