I'm looking for any opinions on mounting a gun safe in my detached garage.

Does anyone else have safes mounted out there?

It's become a space issue inside the house, and the only real alternative is to mount it in the garage.

I'm concerned about moisture, and I'm looking for any opinions on this?

Do you have power? If so, hook up a powered dehumidifier and get a safe that offers an outlet.

Humidity would be your #1 problem. Then i'd be worried about proper security, if your garage is anything like mine, it'll have plenty of power tools and other items to easily break into the safe within arms reach.

Move her shoes into the garage and put your gun safe where they were.

Move her shoes into the garage and put your gun safe where they were.

 

Then go live in the dog house/shed.

If you do put it in the garage, I would recommend "concealing" it from view in some way, the best option being to frame out a small room right around the safe. This will:

• Prevent anyone walking by from seeing a big safe if your garage is temporarily open
  
• Add an additional layer of protection (especially if you use a security door with internal/protected hinges).
  
• Greatly hinder a potential criminal's access to the more vulnerable sides/seams of the safe. They would have to demolish the walls before flipping the safe on its side to have easy crowbar access
  

Of course, you will also definitely need a powered dehumidifier. Other considerations would be central-alarm supervision of the garage and installing a cheap IP camera in the garage as well to keep an eye on your toys when you aren't home.

Agreed with above, but rather then framing out a room itself.. this may be one of those opportunities to fabricate a little hiding place in plain sight. i.e. incorporated into shelving or a workbench with a quick removable face plate.

Make use of a vapor corrosion inhibitor (replace yearly), and a large rechargeable dessicant to remove humidity. I've been using a large Bullfrog emitter http://www.theruststore.com/Bull-Frog-Emitter-Shield-P25C12.aspx.

Nice link. I might have to get a couple of those emitters.

I think you would be fine. Maybe hook up alarm system to it wouldnt be a bad idea. The best thing may be to do is put it under the garage, like in Mr and Mrs Smith. That would be soo cool. Then it is really hidden!