In some cases door latch plate mortises might need to be cut or enlarged.
How to fit a internal door lock.
Shake the door a bit to make sure it is secure.
If the knob is to the right select a right handed door.
Place a wedge at the bottom of the door to keep it in place.
Begin by removing the screws from the door knob on the interior side of your door.
Turn the key so the locking bolt protrudes from the lock and hold the door against the door frame.
Create a mortise and holes for your lock and door handle.
First mark out the place where the strike plate has to be fitted.
This video is about how to fit a door latch and door handle in an interior door.
Mark out the strike plate on the door frame after you ve fitted the lock in the door you need to fit the strike plate to the door frame.
Open the door and stand with your back to the hinges.
Using a square mark this centre line for approximately 4 100mm on the face of the door the pencil mark can be removed later with an eraser or damp cloth.
This allows you to pull the door knobs off the door from both sides.
Tools needed for this job.
If you re installing a pre hung door make sure you get the correct swing determined by the placement of the hinges and doorknob.
Then use a drill to make the necessary holes for installation of your doorknob door handle and lock.
This process will vary somewhat based on the doorknob you are installing.
Fit the wedge into the bottom of the door as close to the wall as possible.
Hold the door latch against the face of the door flush with the door edge and mark the spindle centre on your previously marked centre line see fig 1.
If the doorknob is on the left you need a left handed door.
Remove the two screws from the latch plate on the edge of the door and remove the latch from the opening.