Although I intend to utilize passive solar design, this posting focuses on a thought of how to make roofs using quanset panels. Looking for feedback. Brief "givens": 15 acre semi-arid mountain property (south central CO), former owner's house burned to the ground, great southern exposure,7600ft altitude, well, septic, grid electric, workshop, "break room", unassembled 74'x45'quanset hut. I do not plan on building a Quanset hut; however, I want to use the material for roofing. The reason for this posting is to see if my idea on how to use the Quanset panels for roofing seems plausible. Since a metal roof will have condensation and conduct heat well, I want to assemble the roofs on the ground and use a crane to mount them on the "boxes" for the abode. A cross section of a panel is sort of like -\_/-. The dashes would be on the same level as the top edges of \_/ resulting in the same shape upside down _/-\_ on the inside surface when assembled. For the outside surface recesses I am thinking a spray foam, then a horizontal layer of pink or blue foam panels followed by a basalt mesh with a 1/4" of thin shell concrete. The foam would bring the outside surface level. The pink or blue foam would eliminate external contact of the weather with the metal quanset panels. The mesh and cement mix would make a strong surface. For the underside of the roofing I am thinking of filling the concave recesses with K13, then running horizontal 1x4's filled in with 1" of foam insulation and covered with MgO panels. Building it on the ground would eliminate scaffolding and reduce labor time. I appreciate your input.

Have you priced spray foam? It is a very expensive way to insulate. In my area, the typical installed cost is ~$1/board-ft (12"x12"x1"). Even the DIY spray foam kits available online are around $1/bd-ft. Those panels have pretty deep valleys that would need to be filled.

Thanks arkie6.
I checked on amazon and found you are correct on the price.
Last year I hired a insulation company to spray foam insulate a wall in an old house. They used a bit larger "kit" for the ingredients. I believe they have rigging that uses 55gal drums of the 2 components. I will contact a company near my mountain property to find out about price.
I also checked on the price for K-13 cellulose. It must be bought and installed by a contractor.

arkie6
Your posting got me thinking. I recall attending a thin shell concrete conference in the Portland area in 2004. One of the conference speakers combined EPS beads (like in a bean bag chair) with a concrete mix (not a ready mix). He made a 1" thin 4' arch with one piece of expanded metal lathe that supported his body weight. EPS beads are a lot cheaper than DIY spray foam kits.

I could buy bulk EPS beads with a thin cement mix a lot cheaper than DIY spray foam kits.

Thanks again!

Wouldn't you be better off to use the panels as a cold roof? Meaning build your walls as normal, Use I joists or Dimensional lumber for a ceiling and mount the Steel roof above that?
Then just blow in the space above sheetrock as a normal attic.

whirnot, Thanks for the suggestion. Since posting this I have been looking at ICFs and SIPs for the construction.

Although I like Quad-Lock ICFs, I am looking more seriously now at making my own SIPs. Since my property is in a remote mountain area, it will cost about $250 per cement truck for transportation alone. The distance would require dry mix concrete delivered in cement trucks to the property, then mixed with water. I do have a well, but it would take longer to add the water then mix in each truck. These factors would also impact the pumper truck.

Ordering manufactured-to-plan SIPs would also incur delivery charges and the whole thing would be delivered at once. That means I would need a large enough crew to assemble it quickly or have to protect it from the weather. If I make my own SIPs they can be made in place.

My "floor plan" has gone through many versions on Sketchup as I have considered what to do with the Quanset panels. I am thinking 4 boxes. I could make the SIPs and build each box one at a time, rather than rushing to complete construction. I didn't think about just making the boxes with ceilings and covering the whole box with raw Quanset panels. I do like the idea of one of the boxes having a "vaulted" ceiling. That could be the insulated Quanset roof, or a vaulted SIPs ceiling inside the raw Quanset panels.

The harsh mountain climate means I will still need to heavily insulate the future habitat.

Thanks again to you and arkie6 for your input.