Secure a garage side door by installing a deadbolt. Reinforce the door, jam and hinges to prevent brute-force invasions. Add a second layer of security by securing the door leading from an attached garage into the house the same way. Always keep both doors locked.
Deadbolt locks are available with several security ratings. The best locks have an American National Standards Institute Rating of grade 1. However, even a grade 2 lock provides more security than most contractor-grade locks.
If either the side door or the connecting door has a hollow core, replace it with a solid core unit. Reinforce the door by installing a metal lock plate under the deadbolt. For greatest security, take the time to mortise the area under the lock plate so that it fits flush with the surface of the door.
For a more secure strike plate, replace the existing unit with a heavy-duty one. The new strike plate often extends through the doorframe and into the structural framing of the wall. Install the strike plate with long screws that extend into the framing of the garage. Predrill the holes before starting the screws
Many door hinges are installed using weaker 3/4-inch screws. Make the door more sturdy by removing the screw nearest the weather stripping and replacing it with a 3-inch screw that reaches into the framing.