Spray… cork? Is that just glue+cork bits? Does it end up airtight?

I’ve been pretty excited about steam expanded cork boards, they apparently make for excellent (albeit expensive) exterior cladding. Ditto granules for replacing attic fiberglass, though the additional weight of a thick layer seems like it might be a problem for ceiling drywall.

Seems to be a paint/stucco alternative:

https://www.buildwithrise.com/stories/spray-cork-what-is-it

Oh awesome, just water based paint (20%) and cork bits (80%). Sounds like a really cool material.

No matter the substrate, there is almost no insulation benefit to 1cm of material. It looks like cork has an R value of ~4.0/inch so 1cm is roughly R-1.5? That’s about equivalent or a single pane of glass.

Sometimes you can only economically and aesthetically add a bit until you get to the "tear it down and rebuild".