Apart from the name, what is the difference between Thermafloor and Thermawall? The specifications look about the same to the untrained eye. Is anything done to the PIR to make it more rigid or uncompressible if it is for use in floors? Or is it as I half suspect all down to marketing?

TW50 has a slightly lower compressive strength than TW50 and Thermafloor but other than that there is little difference. It is 125 vs 140 but not exactly a lot when you consider EPS70 is ... 70..!

 

So PIR is half as compressible as PIR 
 

 

The compressive strength of PIR is an interesting one. Speaking to Hilliard Tanner he was saying that PIR is not used for load-bearing foundations, not because it could not take the weight but because it has not been thoroughly characterised. Its physical properties under load are not sufficiently well defined for it to be used. Unlike for EPS.

 

(I am going to use PIR to insulate my insulated reinforced-concrete-raft foundations because the insulation will not be load bearing as I will have screw piles).

Thank you. My application is insulating over a beam and block floor with a 65mm screed over the PIR.  TW can be had a lot cheaper than TF so since it's not load bearing and it has the same (near enough) thermal properties it would be nice to take the economy saving if I can have it.