I am building a workshop on a 1980’s 20’x8′ trailer that used to have a mobile construction office on it. I originally thought I could just fix some things here and there but realized after some weeks of teardown that it would be better to re-build the whole thing with green building in mind.
Another thing I have wanted to limit my exposure to off-gases from polymers. Exposure to plywood on the inside and un-treated wood is pretty much what I have been aiming for. Heating of the workshop will be with a small woodstove. I have ordered wood trusses and will have an un-vented ceiling; I had planned on leaving a small gap at the top of the roof-line for air movement.
My current floor build…I want to apply the insulated envelope logic to all of my trailer surfaces. I am starting off in the flooring and this what I’ve got thus far: trailer frame | Treated 2×4 studs | Treated 3/4″ plywood | 2″ XPS| 3/4″ un-treated plywood. I will not be trying to insulate the cavities in between the trailer frame and wood studs.
Regarding the floor build…
-Should I add house-wrap as the last barrier before the 3/4″ un-treated plywood?
Regarding exterior walls…the plan is: un-treated stud | 1/2″ plywood | housewrap and flashing along windows, bottom and top sills, etch | 1×4 furring as a rain screen | 2″ XPS | metal siding
My roof was going to mimic my exterior walls but now I am concerned about not having enough insulation on my roof. I really don’t want to expose myself to insulation, like the foil-backed polyiso I keep seeing everywhere.
Many, many thanks in advance!
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