How To Install a Lock on a Interior Door

Set Up and Initial Drilling

The tools you’ll need to begin are a Ruler or Measuring Tape, a Drill, a 2 1/8 –inch and a 1-inch Hole Saw, a pilot bit and a pencil. To begin, first measure up 36 inches from the floor up to the door on the side where the lockset will be installed. This will be the height of the handle or knob you are installing. From there you will then measure either 2 3/4-inches from the edge of the door inwards (depending on the backset of the lock, you may have to measure 2 3/8 instead). Once you have done both those measurements you will mark a cross on the door with the centre of it being 36” up from the floor and 2 3/4 in from the edge of the door. You will then use your 2 1/8 hole saw to start drilling through the door with your pilot bit placed on the centre of the cross you marked. Make sure you hold the drill straight and are not tilting it left, right, up or down as this will make installing the lock more difficult and can cause the lock to not work properly. Once you get far enough into the door where your pilot bit pokes out the far side of the door you now want to stop drilling. If you were to continue going straight through the door the wood could splinter and break causing cosmetic damage. What you do instead is take your drill out, move to the far side of the door and place your pilot bit into the small hole you made and finish drilling right through.

Drilling For The Latch

After that is all done we now want to mark for the hole to place the backset into.  You will once again measure 36 inches from the floor up the side of the door to keep it inline with the previous hole we drilled. Then we want to mark halfway in from the edge of the door for the backset. This measurement can vary so how you determine it is based on the thickness of your door. What you want to do is measure how thick your door is then divide that number by two (e.g. A 1 ½ inch thickness means you mark your centre at ¾ inch in from the edge).  Once you have both those measurements make a cross with your pencil to have the centre point clear for you to see when drilling. When you are ready get your drill and 1 inch hole saw and drill into the door from the edge. Yet again, make sure you are drilling as straight as possible to avoid complications with installation and your locks function.

Beginning Lock Installation

Now that your holes are made we can start installing the lock onto the door. Start by inserting your latch into the 1-inch hole at the side of the door. You should have a silver ring around the end of the latch that will make sure once it’s fully inserted it fits in snugly. Double check to see if you have the right backset on it by seeing if the centre of the latch is in the middle of the 2 1/8 inch hole. If it’s not correct adjust your backset to the proper length. You may have to use your 1-inch hole saw and drill in further if you find the latch is bumping into the inner part of the door.

Finishing Lock Installation and Strike Mounting

After that is done grab the two halves of the lock you are installing and find which side is the inside and which is the outside. The inside of the lock is always the side where you insert your screws because if you were to place that side on the outside of the door your lock could be disassembled from the outside and we don’t want that. Insert the outside of the lock into your 2 1/8-inch hole and match up the centre of the lock with the centre of your latch. While holding this side in the door place the inside of the lock up against the other side careful to line up the screw holes with there they will be inserted so you don’t have to fish for the holes. Insert your screws and tighten them snugly making sure not to over do it as you can cause damage to your door and cause your lock to function improperly. Try out your lock and make sure it operates smoothly and feels sturdy

To mark where your strike will be mounted onto the frame of the door measure 36 inches up from the floor and Drill a 1-inch hole in the centre of the frame. After you have done that and screwed the strike onto the frame close your door to make sure your lock latches properly, you may have to adjust it left or right to make sure it is closing properly. Once that is done you are finished. Be sure to clean up all the sawdust you have made with all your drilling and congratulate yourself on a job well done!