Novice sauna DIYer looking for advice… I’ve been busy fixing up this steel framed horse float for a mobile wood-fired sauna. There’s so much info (and misinformation) around and I’m stuck on what to do.
Floor:
I have planks of reclaimed Douglas fir that I’m planning to use for the floor, but also have bought 3mm epdm rubber coin mat. Should I:
A) buy marine ply, top with the rubber, make a trough drain and use the planks to make duckboards?
B) just use the planks to make a deck and allow the water to drain naturally? If I do this, how do I prevent wood rot underneath from the rising damp/roads etc.? And how to seal the vapour barrier at the base?
I’m in SE Australia, winter night temps often around 0°C, summer day into the 40°s. Don’t want spiders getting in.
Insulation:
I also keep flipping around on insulation options… I can’t find an Australian supplier of sauna grade polyiso boards (we don’t have FF-PIR or Kingspan Sauna Satu here) and I don’t want to lose too much internal space to rockwool… my external cladding will be half corrugated tin, half charred Tasmanian oak/Vic Ash (eucalyptus hardwood). Internal lining will be reclaimed Doug fir. How essential is insulation in Australia (Vic/Tas) if the timber is thick?
Many thanks in advance!