Insulation board over drywall in a dome
I live in a geodesic dome in windy, cold Wyoming. It was built in 1985. The original ceiling is sheetrock which, in a dome, only lasts about 10 years before it begins to crack at the seams do to the natural movement of a dome. I had the sheetrock replaced in the loft/upstairs and because of the triangles and tight space, it was quite the ordeal. The contractor said he’d never do it again.
I want to insulate the ‘vaulted’ ceiling over the living room and I know that it needs new insulation. The cracks between the triangles are ugly. I am avoiding tearing down the existing sheetrock, and I think I may have come up with a solution if it is something that would actually insulate, that I can do myself (I’m a 60 yr old woman), and that won’t require the contractor, the cost, and the mess and waste that tearing down the sheetrock would make….
How about cutting insulation board into triangles, covering it with a lattice ‘wallpaper’ type material I’ve found (so it looks like wood) then glue the insulation board over the top of the sheetrock, and spray a low-expanding foam between any cracks and trim with wood (screwing into the framework) on all sides of each triangle? It would certainly look pretty (I’ve noticed lots of dome ceilings are wood – can’t afford that one), but would it actually add insulation value to the ceiling as it would be inside the dome? Is there a glue other than spray foam that would defy gravity, or would the wood trim do that work?
I had to make boxes for artwork 20 years ago and I needed them to be lightweight but strong. I used roofing board, spray foam, and 1×2’s all around. Last week I tried to break them apart but couldn’t! I had to take a saw to them. They were very strong and built much like I am considering for the ceiling. But they didn’t need to insulate. Will it do the job on top of sheetrock?
Thank you much in advance for any and all responses!! Photo shows a small portion of the dome’s ceiling with a corner of the large skylight.
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