Garage and Secondary Doors: The Often-Forgotten Security Points

Most homeowners think about security in terms of the front door. The front door has the deadbolt, the smart lock, the prominent hardware. Burglars rarely use the front door. They use the side door, the back door, the garage entry, the basement door, the door that hasn't been thought about in years. Every secondary door deserves the same security attention as the front door, and most don't get it.

This article walks through the secondary doors typical homes have and what each one specifically needs.

The garage entry door

The door from the garage into the house is one of the most overlooked security points. In many homes, this door has a builder-grade lock, no deadbolt at all, or a thumb-turn lock that any teenager can defeat. The thinking, presumably, is that the garage door itself is the security barrier.

Garage doors are not security barriers. They can be defeated in seconds by anyone with the right knowledge — using a coat hanger to pull the emergency release, exploiting weak spring openers, or simply tailgating in when a homeowner pulls in. Once inside the garage, an attacker has time and concealment to defeat whatever lock is on the door to the house.

The right configuration for the garage entry door:

A Grade 1 or Grade 2 deadbolt (just like the front door).

A heavy-duty strike plate with three-inch screws.

A solid-core or steel door (not hollow-core).

If glass is part of the door, reinforced glass or no glass.

The garage entry door deserves exactly the same security as the front door. It is, in practical terms, an exterior door — just one that happens to be inside the garage.

The back door

Back doors and side doors get used less often than front doors, which means they get inspected less often. Worn locks, sticking deadbolts, misaligned strike plates, and broken hardware tend to accumulate. The back door also tends to be less visible from the street, which makes it more attractive to burglars who don't want to work in plain view.

A back door inspection should cover whether the deadbolt extends fully into the strike plate, whether the strike plate is secured with three-inch screws, whether the door closes cleanly without lifting or pushing, whether the hinges are in good condition with appropriate-length screws, and whether the lock is the same grade as the front door's lock.

Any "no" on those questions is something to address. Back doors should be at the same security level as front doors, full stop.

Sliding glass doors

Sliding glass doors are notoriously vulnerable. The factory locks are typically minimal — a small latch that can be defeated by lifting the door slightly out of its track. Many sliding glass doors can be opened by anyone willing to spend a few minutes with basic tools.

The standard upgrade is a secondary lock. Several options:

Pin locks. A small metal pin that drops through both the moving panel and the fixed panel, preventing horizontal motion. Cost: five to twenty dollars. Effective for ten dollars worth of metal.

Foot bolts. A bolt at the bottom of the door that pins the door to the floor track. Cost: twenty to fifty dollars. More secure than a pin lock but requires more installation effort.

Security bars. A bar that fits in the floor track, preventing the door from sliding even if the lock is defeated. Cost: fifteen to forty dollars. Highly effective and visible.

Anti-lift devices. Stops the door from being lifted out of its track entirely. Cost: ten to thirty dollars. Solves the lift-and-bypass attack specifically.

Combining two of these — typically a pin lock plus a security bar — is appropriate for most residential applications. A locksmith can install all of these in a single visit.

French doors

French doors share many of the issues with sliding doors but have different mechanics. The two doors meet in the middle, with one door typically being the "fixed" door (locked to the frame top and bottom) and the other being the "active" door (with the deadbolt that engages the fixed door).

Common French door issues include the fixed door's bolts (top and bottom) often being weak or missing, the astragal (the vertical strip where the doors meet) often being damaged, and the deadbolt engaging another door rather than the frame, which is inherently less secure than a frame engagement.

Upgrading French doors typically involves heavy-duty top and bottom bolts on the fixed door, a flush bolt or surface bolt that makes the fixed door fully immovable when locked, reinforced astragal, and confirming the active door's deadbolt has a one-inch or longer throw.

A locksmith experienced with French doors can identify which specific upgrades each door needs.

Basement doors

Basement doors split into two categories: doors connecting the basement to the inside of the house (interior doors) and doors connecting the basement to the outside (exterior doors).

Exterior basement doors — particularly bulkhead doors that lead to the yard — are often surprisingly weak. Many bulkhead doors have only a hasp and padlock, or a simple lock that can be defeated with hand tools. They're also often hidden from street view, which makes them attractive to burglars.

Upgrading exterior basement doors involves replacing builder-grade locks with Grade 1 or Grade 2 deadbolts, adding heavy-duty strike plates with three-inch screws, considering adding a hasp with high-security padlock as a secondary lock, and for bulkhead doors specifically, ensuring the doors close fully and the locks engage cleanly.

Interior basement doors are less critical for outside security but matter for general home access control. A worn-out interior basement door lock that can be jiggled open is an annoyance more than a security risk, but worth fixing.

Shed and detached structure doors

Sheds and detached garages often contain valuable items — tools, equipment, bikes, recreational gear — and often have minimal security. A common pattern: thousands of dollars worth of tools secured by a five-dollar padlock from twenty years ago.

Upgrades for shed and detached structure doors include replacing cheap padlocks with hardened-steel high-security padlocks (thirty to eighty dollars each), adding a heavy-duty hasp if the existing one is light-duty, considering a quality hasp lock that integrates the padlock and hasp into a single unit, and for sheds with significant valuables, considering a Grade 1 deadbolt rather than just a padlock.

A locksmith can recommend appropriate hardware for the specific use case and install it during a routine service call.

Pet doors

Pet doors are entry points that homeowners install intentionally. Most pet doors are large enough that a small adult or older child can squeeze through them, and many burglaries have been committed by attackers who entered through a pet door.

Mitigations include electronic pet doors that open only when the pet's collar tag is in proximity (significantly more secure than a flap pet door), sliding panel pet doors that have a manual sliding panel that can be locked when the homeowner is away, and keeping the pet door blocked when away (even a flap pet door can have a sliding panel inserted on departure).

If the pet door is a regularly-traveled-through opening for the homeowner's pets, eliminating it isn't practical, but the choice of pet door type matters significantly for security.

Mail slots

Mail slots in doors are usually small enough that they don't admit a person, but they can sometimes admit a tool. Some attackers use mail slots to fish for keys hung near the door, to manipulate thumb-turn locks from inside, or to deliver other attack tools.

Modern security best practice is to avoid leaving keys near the mail slot, ensure the deadbolt's thumb-turn isn't reachable through the slot, and consider replacing wide mail slots with narrower ones if the slot is a vulnerability.

The bigger picture

Home security is rarely about one heroic lock. It's about every entry point being adequate. A house with a four-hundred-dollar high-security front door deadbolt and a five-dollar builder-grade lock on the garage entry door is a house with five dollars of security — because the attacker chooses the weakest entry point.

A whole-home security walkthrough by a residential locksmith identifies every door, every window, every secondary entry, and produces a prioritized list of upgrades. Cost for the walkthrough is typically one to two hundred dollars; the resulting list of fixes can usually be addressed for a few hundred to a thousand dollars total. The result is balanced security across all entry points — which is what actually protects a home.

What makes secondary doors different

Front doors get attention because they're visible and used daily. Secondary doors don't get the same attention because they're often used only occasionally and aren't visible from the street. The neglect compounds over years until the secondary doors are significantly weaker than the front door.

Catching this pattern requires intentional effort. Walk through your own home occasionally and inspect every entry point as if you were trying to break in. The doors that look easy from this perspective are the ones that need upgrades — regardless of how rarely you use them.

A locksmith doing this walkthrough professionally finds the same patterns the homeowner would find, but with the experience to recommend specific fixes and the equipment to implement them. The combined service is more efficient than the homeowner trying to address each issue separately over years.