Install a Deadbolt Lock

A deadbolt is not like a spring bolt which can be easily opened, a dead bolt does not open unless the lock cylinder is rotated.
A slight variant of the standard deadbolt is the vertical deadbolt. The vertical deadbolt generally rests on top of a door. Vertical deadbolts avoid insertion of pry bars between the door and the frame and hence are safer.
The common types of a deadbolt lock are:

  1. Single Cylinder
  2. Double Cylinder
  3. Single Cylinder with removable thumb turn

Many designs are available from manufacturers. Different manufactures have various designs which offer solution to defend the lock from being picked or opened with force or any other method. However, most manufacturers offer product lines of deadbolts that promise higher levels of resistance to break and entry and defeating than other product lines by the same manufacturer

For a deadbolt installation, a locksmith will charge about $125. You yourself can buy and install one for only about $35. Given that the exterior door is made of wood, then deadbolt can be installed quite easily. In case you have a steel or fiberglass door, hire a locksmith to do the job. This is because machines such as takes heavy-duty drills and bits are used to cut into these tougher materials.