May be wrong place to post; however, I live in SE Kansas...hot in summer...cold in winter...periods of lots of rain and humidity...I have a metal shop with cement floor and insulated ceiling...but not the walls...no Heat or Air...l am wondering about putting a gun safe in it and being able avoid rust, problems etc...Any like experiences or suggestions...Thanks

I've always had my safe in a climate controlled area. My brother in law keeps his in his garage with a dehumidifier rod and his rifles seem to be holding up fine.

One thing I would caution you about. I don't know what tools you own but if cutting torch or abrasive saw is one of them be sure to lock it up in the safe! Years ago I had a rifle in Mark Strattons shop and he had a break in. They simply lit his torch and opened the safe! Fortunately my rifle was just a bunch of pieces at the time and was deemed unworthy to the thieves.

Mine's in my garage, no air/heat out there, I use a golden rod and have been very pleased!

Yeah, the Golden Rod.
I'd also be thinking big silica bags inside a container with adjustable openings and a humidity meter for the warm season. It's going to be tough, if you have wood stocks, to keep them from doing mysterious things.
I'm lucky, here it is not humid, but not bone dry either.

I've had a couple of safes in my garage sitting on the concrete floor for years (SoCal) without problems, both have Goldenrods and haven't had any problems. Just wondering, any chance that moisture could collect under the safes? Should they sit on wood blocks to keep them off the floor?

1/8 " UHMW through bolted to floor.

Yes...thinking if I ever do put one there I would put it on some four by four....

I have another option in the house; however, it would be in same room with the washer and dryer...it is climate controlled but maybe worse?? Also a lot more work to get it in if possible at all....