- A gap wider than an eighth of an inch is enough for a pry bar or a shim.
- A hollow core door sounds like a drum and cannot hold a bolt whatever lock you fit.
- Outward opening doors need non removable hinge pins or a security stud hinge.
- Walk the whole property. The sliding door and the garage service door are entrances too.
Reading a door for weakness
Start at the gap. A gap wider than an eighth of an inch between door and frame gives room for a pry bar and often room for a shim past the latch. A sagging door that scrapes the sill has dropped on its hinges and its bolt is no longer aligned with the strike.
Check the door itself. A hollow core interior door fitted as an exterior door will fail around the lock no matter what lock you fit, because the bolt is anchored in a cardboard honeycomb. Tap it. A hollow core sounds like a drum.
Check the frame for splits, especially around the existing strike. Old damage that was painted over is a repair the customer does not know they need, and pointing it out before it fails is the difference between a technician and a salesperson.
Hinges and outward opening doors
On a door that opens outward the hinge pins are on the outside. Anyone with a screwdriver can drive the pins out and lift the door off from the hinge side, leaving the lock entirely irrelevant.
The fix is a set of security hinges with non removable pins, or a hinge with a fixed stud on one leaf that drops into a hole in the other so the door cannot be lifted even with the pins gone. Both are inexpensive and both take minutes.
On any door, replace at least two hinge screws per hinge with three inch screws into the stud. Hinges fail in a kick as often as strikes do, and nobody reinforces them because nobody looks at them.
Sliding doors and secondary entrances
Sliding patio doors are the entrance most often ignored and most often used. The factory latch is usually a light hook into a thin aluminum frame, and many can be lifted out of the track entirely.
Fit an anti lift device or adjust the rollers so the panel cannot be raised, then add a secondary lock. A pin lock through the frame at the top of the fixed panel is far stronger than a bar in the track, and it can be positioned to allow a ventilation gap.
Walk the whole property when you are already there. Garage service doors, basement hatches, gates and pet doors are all entrances. A pet door large enough for a person is a door, and quite a few of them are.
Common Questions
My door will not latch since the weather changed. Why?
Timber swells and the frame moves, so the latch no longer meets the strike. Adjusting the strike or the hinges fixes it. Forcing the door makes it worse.
Can any lock be fitted to any door?
No. Backset, bore hole size and door thickness all have to match the existing prep, or the door needs cutting. Measure before buying.
Is a steel door always more secure than a wooden one?
Only if the frame matches it. A steel door in a soft timber frame fails at the frame, and a solid core wooden door in a reinforced frame outperforms it.