@Gabriel Anderson As in they develop a lot of condensation which can then seep into the gaskets etc?

I agree! Working on finding a dealer here. Supposedly it is sold here via sauna360

I'm actually finding a few places that may carry it or something like it. And they're in Canada. https://bsaunas.com/product/sauna-thermal-vapour-barrier-foil/ https://www.blackstonesaunas.com/product-page/aluminum-foil This might also be it: Finnish Sauna Builders

Hey @Tom Mooney , thanks for sharing this. Is there a general calculation you use to estimate airflow based on vents and sauna volume? I have an intake vent behind heater and and exhaust vent opposite side at the top of the wall. As it stands, they will be gravity vents. But I am also considering using electric

@Tom Mooney Sounds like some cool tools haha. Awesome, and its square footage, not cubic footage that we multiply by # of air exchanges? Thanks for sharing

@Tom Mooney I don't know if that's accurate. It seems like double pane is pretty common for sauna use. The sauna architect I used in Finland suggested double pane. I suppose some double pane windows may have air vs inert glass. I'd have to check

Nice, yes, I am going to use cement board below and behind the stove on the walls. I was thinking black slate and or black river rock.