Hi all,
We've got the following two options, please can you advise ?
Option 1
Kingspan K103 at 75mm depth
45mm to 65mm of sand/cement screed with hardener
Option 2
Kingspan K103 at 75mm depth
2nd layer of floor insulation at 20mm depth
25mm to 45mm of Liquid screed
Thought process is:
The K103 is already purchased and on-site, so no option to go with a different product
This would be a significant improvement in performance: u value goes from 0.158 -> 0.138
A liquid screed would conduct more heat into the building, rather than below the house, so would be more efficient to run
Key notes:
1) This is on Ground Floor. Construction is beam and block.
2) We have UFH.
Questions:
1) Does this make sense ?
2) Is there a disadvantage to a liquid screed ?
3) Are there any issues with laying a 20mm depth PIR on top of a 75mm depth PIR ?