Ok, another design question. My North wall/roof construction will likely consist of the curved trusses, then a layer of pine boards, then a piece of black visqueen plastic, then 4" of strofoam (1" sheets to conform to the curve), then horizontal purlins, then metal roofing.
I was talking to a building guy and he reminded me that styrofoam is not that great on the environment. I'm not sure how bad but he suggested rock wool insulation panels instead. All my searches for rock wool sheets find something marketed as more of a sound proofing material. Rock wool bats are available but I'm hoping to use a sheet product to allow for the somewhat simple design laid out above. I'm not sure if I'd need some sort of waterproof membrane (housewrap) outside the rock wool to protect it?
I could make batts work if I put the pine on the inside of the trusses, visqueen between the pine and the trusses, then the batts between the trusses, then purlins outside the trusses, then the roofing. I'd have more thermal bridging and installing the stuff would all be overhead from inside, vs just laying the materials on from the outside.
Anyone with experience with rock wool panels or insulation who can comment? Thanks!