I am designing a 4'x4' sauna. Most information online is for indoor saunas. From what I've gleaned, the layers should be (for example):
Outside ––> cedar exterior ––> tyvex ––> strand board --> 2x4 frame with insulation (what grade?) ––> vapor barrier ––> cedar interior
Is this sufficient? Is it overkill?
It's an outdoor sauna and so should be able to retain heat year round. Are there any special considerations to be taken given that 1) it will be used outside and 2) it will be a near infrared sauna heated by red heat lamps (so much less moisture than a traditional steam sauna, dry rather than wet heat).
I need the sauna as part of a health regime to manage a severe mold sensitivity, and so as you can imagine, insuring there is no mold growth is quite important!