Insulating a metal shop?
You can have three feet of insulation and sooner or later the interior temperature will equal the exterior temperature. I studded out my shop and have 14" of fiberglass in the roof and 8" of fiberglass in the walls. Even then I had to put in a 28,000 BTU/hr wall air conditioner to make it tolerable on 100 degree days. This is for a work area of 25' X 50'.
You can have three feet of insulation and sooner or later the interior temperature will equal the exterior temperature. I studded out my shop and have 14" of fiberglass in the roof and 8" of fiberglass in the walls. Even then I had to put in a 28,000 BTU/hr wall air conditioner to make it tolerable on 100 degree days. This is for a work area of 25' X 50'.