Reply To: [unofficial weekender] BYOI

[sundancer 44307xp 0]

The stuff for isolation is XPS. From what I can tell with my rudimentary understanding of the Dutch language, this manufacturer has a good run down on what it is

https://www.soprema.nl/isolatie/xps

So if you get big, thick sheets they are usually sold in packets online through local’ish hardware stores. HTH