What Is the Best Lock for a Storage Unit? A Colorado Springs Locksmith's Guide

For most storage units, the best lock is a disc lock: a round padlock whose shackle is almost completely hidden inside the body, so bolt cutters have nothing to grab. Pick one with a stainless steel body, a 3/8-inch shackle that fits your facility's latch, and a keyed (not combination) cylinder. If a disc lock does not fit the latch, use a padlock with a shrouded shackle, and if your facility offers its own cylinder lock built into the door, that is usually stronger still.

Storage security is a live question in Colorado Springs this month. On November 13, KRDO reported that Colorado Springs police had arrested a man in connection with a series of garage and storage unit burglaries in the Stetson Hills area, a case the Metro Burglary Unit had been working since August. Storage units are an easy target for the same reason garages are: they sit closed and unwatched for weeks, and the only thing between a thief and everything inside is one lock on one latch.

The Three Types of Storage Unit Lock

Disc locks: the best choice for most units

A disc lock is a flat, round padlock. The shackle curves out of the body for only a short distance, and once it is closed through the latch there is almost no exposed metal to cut. The round shape also makes it hard to get a pry bar or a hammer on it. Most self storage facilities sell or recommend them for exactly that reason. Look for a solid stainless steel body, which does not rust through a Colorado winter, and a keyway with a cover or shutter that keeps snow and grit out.

Shrouded-shackle padlocks: the next best

A regular padlock with tall metal shoulders around the shackle, called a shrouded or closed shackle, protects most of the shackle from cutters. It is a good choice when a disc lock will not fit the latch on your door. Avoid a standard open-shackle padlock with a long, thin loop. It is the lock thieves cut first, because it takes seconds.

Cylinder locks: the strongest, if your facility has them

Some facilities fit a cylinder lock into the door itself, so there is no shackle at all. You buy or rent the cylinder from the facility office, and only your key opens it. If your facility offers this, it is usually the strongest option you can get, because there is nothing outside the door to cut.

What to Check Before You Buy

• Shackle size. Most storage door latches take a shackle about 3/8 inch thick. A thinner shackle cuts faster, and a thicker one may not fit through the hole. Measure the latch, or ask the office, before you buy.
• Keyed, not combination. A cheap combination padlock can often be opened by feel, and the numbers can be watched over your shoulder. A keyed disc lock with a good cylinder is harder to defeat quietly.
• Weather resistance. Units here go through freeze and thaw all winter. Stainless steel or brass resists rust, and a covered keyway stops water getting in and freezing. Our guide to opening a frozen lock in winter explains why a frozen keyway should never be forced.
• Your facility's rules. Some facilities require a specific lock, sell their own, or use an overlock on units with late rent. Ask at the office so your lock is not cut off by mistake.

Beyond the Lock: How to Make a Unit Less Tempting

• Choose an inside or well-lit unit when you can, close to the office or the gate camera rather than at the far end of a row.
• Check on the unit regularly, so a cut lock or a bent latch does not go unnoticed for weeks.
• Keep a photo inventory of what you store, with serial numbers for tools, bikes and electronics. It helps the police and your insurer if something is taken.
• Do not advertise what is inside. Leave valuable items toward the back, behind boxes, rather than in view when the door goes up.
• Ask about coverage. Your homeowners or renters policy may or may not cover items in storage, and many facilities offer their own protection plans. Check before you need it.

The Same Thinking Applies to Your Home Garage

The Stetson Hills case involved home garages as well as storage units. A garage holds the same things people store, bikes, tools and sports gear, and it is often protected by less. Keep the overhead door closed, lock the side door with a real deadbolt, and never leave a garage door opener in a car parked outside. Our garage door lock service in Colorado Springs covers side doors, utility doors and keyed garage hardware, and our guide on the security gap most smart garages leave open covers the door from the garage into the house.

Lost the Key to Your Storage Unit Lock?

A good disc lock is built to resist cutting, which is exactly what makes it hard to get off when the key is gone. Start at the facility office: most will ask you to show ID and confirm you are the renter on the lease before anyone removes a lock, and some will only let their own staff or a locksmith do it. Then call a locksmith rather than attacking it with a grinder, which can damage the latch and the door. As a mobile locksmith in Colorado Springs, we come to the facility, open or remove the lock, and can fit a new one on the spot. If you keep several padlocks for a unit, a shed and a gate, ask us about having them keyed alike.

Frequently Asked Questions

Are disc locks really better for storage units?

For most units, yes. The shackle is almost completely covered when it is locked, so bolt cutters cannot get a grip, and the round body is hard to pry or hammer. A cylinder lock built into the door is stronger still, if your facility offers one.

Is a combination lock OK for a storage unit?

It is better than nothing, but a keyed disc lock is the safer choice. Cheap combination locks can often be opened by feel, and nobody needs to steal a key to learn the code.

What size lock fits a storage unit door?

Most storage door latches take a shackle about 3/8 inch thick. Measure the hole in the latch or ask the facility office before buying, because a lock that does not fit cannot be closed properly.

Can a locksmith open my storage unit lock if I lost the key?

Yes. Check with the facility office first, since most want proof that you rent the unit before a lock is removed. Then a locksmith can open or remove the lock without damaging the door, and fit a new one.