Do these meet in the middle or just one door? Not sure about why not metal and a key.

I a barn door really secure? If you mount it on the insider wouldn't it be easy to push it in off its track. If mounted on the outside then they would be easy to lift off the track.

Gee, I never thought of how actual barns, with actual barn doors, are secured!

A very large screw.

Kind of difficult to advise without knowing what kind of handles, if any, are on the doors. What do the doors look like?

What about a bike lock system like this. ? You could also purchase a combo lock box like real estate agents use.

Real barn doors are rarely locked in my experience . I have never had an issue with a good lock for my sheds with a key. I need to see the issue.

Search for lockable slide bolt or gate latch

Universal keys to your locked shed.

Install a loud alarm and flashing lights linked to your home security system. Midnight shoppers don't expect it.

I have only had barn doors where horses lived inside, so we never locked them. Mark gave you the best idea unless you want to go digital/web-based.

"Real barn doors are rarely locked in my experience ."

In my experience real barn doors have a few loaded shotguns and rifles within range and nobody is stupid enough to try to open those doors without permission, locked or unlocked.

I have my horse at a stable no locked barn doors no rifles nearby and not one time has anyone gone into the barn who did not belong there . A shed is IMO a bit different usually in the town or city but without info who knows what this situation is. I do agree if someone wants in no lock will deter them.

If you google ’barn door lock’ there are several good options that pop up.

You’ll have tracks along the top and bottom that will prevent the doors from being removed, yes? Is there a possibility that mice could get in through any gaps? (I guess they can find their way in anyhow.)

Hasp and a good padlock, but I don't think I've ever seen a locked barn door.

Did anyone else tink the title qwestion was a poor attempt at pirate talk, arrr?

Ours is always locked if not taking things in and out. I'm not sure why, its many yards from the house but at the top of a very steep back hill. Our property drops off sharply to the short street below. (I can almost climb it, DH does better in caulked boots) When the fixed plate is slid into the closed position, it lines up with a same sized heavy eye below. Weyerhaeuser gate padlock. DH keeps the key in the garage that's attached to the house.

I think the only gas powered tool kept in the garage is the gas back pack blower this time of year when leaves down are a daily occurrence. But there are several other things in the shed that would be expensive to replace. Two lawn mowers (doesn't everyone have to have one that 'vacuums' particularly well while the other is excellent at cutting), two gas edgers, weedeater etc....