First you need to choose a lock and read its instructions. Locks are overhead, mortise, mortise latches with handles – keys. Usually the lock is cut at a height of 90 – 110 cm from the floor.
As a rule, overhead locks are installed on the entrance doors. Fastened with screws on the inner surface of the door leaf and door trim. The first step is to make a hole for the lock rod with a drill and chisel. Then the lock is applied to the marked place, the location of its front bar at the end of the door is designated, and with the help of a chisel, a recess is made under it – a “nest”. Then the lock is again applied to the door and the screws are marked with a pencil. The strip should not protrude beyond the surface of the door end face.
Having secured the lock, the door is closed, the position of the locking box is marked and it is also fastened with screws.
Mortise locks are usually installed with a handle with a key hole. The lock cuts into the end of the door trim. When cutting into a paneled door leaf, the lock cannot be cut in front of the middle beam of the jamb, as the hole will loosen the spike connection of the door.
To begin with, the place of the lock insert is marked. The contours of the lock, attached with the end side to the harness, are circled with a pencil, with the help of an awl, mark the keyhole.
Then transfer the placement of the lock to the side of the strapping and mark the thickness of the lock with a pencil along its axis. From the end of the door along the marked contour, holes are drilled with a depth along the length of the lock and with a chisel they make a recess along its contour. After that, the lock is tried on, the outline of the end of the lock is drawn and a recess is made so that it is flush with the door frame.
In order to mark the installation location of the strip located on the door frame, the door is closed. A notch is made according to the mark for the bolt or latch bar.
To mark the recess under the lock bolt, rub the bolt end with chalk or whitewash, close the door and carefully turn the key. Thus, a place for the nest is marked.
Another way is to thinly smear the door frame opposite the crossbar with a layer of plasticine and push the bolt with the key. The imprint left from it will be the place of the hole for the strike plate.
The bolt hole can also be determined using a sheet of paper: a quadrangle is cut out according to the size of the area of the crossbar end, one side of which is moistened with water and carefully glued to the crossbar end, and glue is applied to the other. After they close the door, turn the key, thus pressing the bolt to the door frame. The paper sticks to the jamb and indicates the location of the hole.
Mortise latches, equipped with dowel handles, are attached in this way: they mark the place where the handle is installed, then select a tree under the latch body with a drill and a chisel, and drill a hole for the rod on which the handles with strips are attached. The latch is inserted into the slot and secured. After that, a rod is inserted into the latch body, then a handle with strips. The structure is fixed with screws. To ensure the softness and soundless operation of the handles, the latches are lubricated with petroleum jelly or oil.