FITTING A NIGHTLATCH
Night latches should always be positioned at shoulder height for easy access.
Start by measuring the distance from the centre of the cylinder to the outside edge of the latch case. Mark this distance from the door edge at the height you want to position the lock.
Cylinder barrels vary in the size and shape of the hole needed to accommodate them. With some it may be easier to fit a drill bit of the correct size and bore a hole for the barrel. But you can just as easily drill a series of holes to the correct shape using a 6mm bit. Use the mark on the door as a guide and drill as slowly as you can, trying to keep the drill at right angles to the door.
Once a clean hole has been made you can fit the cylinder and latch pull. Push the latch pull onto the cylinder and then slide both into the hole from outside the door.
Move round to the inside and fit the backplate. It is held in place by a number of screws which fit into the back of the door.
Two longer retaining screws push through the backplate and hold the cylinder in place.
The connecting bar and retaining screws which link the cylinder barrel with the latch are made to suit the thickest doors available. Consequently on many doors they will be too long. Once the backplate is in place it should be possible to check.
Hold the latch case in place so that the bar engages in the latch.
By looking at the latch sideon you should be able to judge how much, if any. Of the bar needs to be trimmed. If it is too long, unscrew the cylinder and cut the bar to length with a junior hacksaw.
Replace the cylinder and then screw the latch case to the backplate. The fixings vary from one type of nightlatch to the next. Some have two end screws which fit through the side of the case; others have four screws, one in each corner of the backplate.
The last jo h is to fit the latch to the door jamb. Remove the wedge, shut the door and hold the latch in position against the jamb. Mark around the outside with a pencil. Then open the door and mark the depth of the latch on the jamb.
Chop out the waste with a 12mm chisel and mallet, having first indented all around the markedout line with the chisel. Try not to remove too much wood at once; work slowly down to the required depth, occasionally stopping to try the latch for size.
Now screw the latch to the jamb. Most latches are held by three screws, two fitted through the end plate and one which screws diagonally through the centre of the latch. Finally, close the door and test the lock.