Locks for doors

The average home contains at least ten doors most of which have various functions and require different locking devices. You should fit both interior and exterior doors with good quality locks which offer proper security and do not hinder everyday life for members of the household. When considering home security it is a good idea to start by making a floor plan of your home: take exact measurements of door thickness and door stile widths and note the condition of lock already fitted. This plan will help you to examine the cost of overall security requirements and to order the devices and fittings you will need.

carpenter fitting door lock

Types of door
Outside doors should be at least 45mm thick and made of stout hardwood or security uPVC . There is little point in fitting expensive security devices to doors which are weak and likely to be broken down easily.

Front door
This is usually the most vulnerable door since it is the one you use to leave the house and therefore cannot be bolted from the inside. Approximately 28 percent of all break-ins occur from the front of private houses. Many front doors are fitted with o1d fashioned rim locks (a cylinder mounted inside and through the door): you can secure the door by adding a one bolt, five or six lever mortise deadlock (a box mounted inside the door) or replace it with a rim lock and a lockable handle which has the deadlocking function. If the stile is under 75mm wide, you will have to fit the former or a special narrow rim deadlock. The door must have a minimum thickness of 38mm for both types. If you decide to replace the rim lock, buy one of similar dimensions so only slight modification will be needed to fit it. The standard mortise lock has two keyholes and is fitted into a mortise in the edge of the door; it is suitable for double doors if one door is locked with flush bolts. Double doors with a rebate require a rebated forend and a rebated locking plate which must be stipulated when the lock is ordered; you should quote the hand of the lock. whether the door open inwards or outwards and the depth of the rebate. To determine the hand of a lock, view the door from the outside: the edge on which the lock will fit is the hand. If the lock is for the edge of the door on your right a right-hand lock is required. Two security or mortise bolts fitted top and bottom of a front door will give additional security. A security chain will guard against unexpected intrusion if you remember to secure it before opening the door to strangers. Fit a door viewer to allow visitors to be identified before the door is opened.

Back door and side door
Approximately 62 percent of break-ins take place at the back of house. Low security locks should be replaced with a standard or two bolt mortise deadlock of at least five levers and two bolts can be added as additional security. If the door is glazed, it is better to use mortise bolts. If trades people and callers are expected you should fit a chain and door viewer.

French doors
An intruder can easily open these type of doors.Fit a mortise lock and mortise bolts, one shooting upwards into the top of the frame on one door and the other to the second door (which overlaps the first), shooting down into the floor.

Metal doors
These are normally made of galvanized steel or aluminium and are supplied with good locks. Aluminium replacement doors for domestic use are usually supplied with narrow stile widths which require rim fitting mortise deadlocks or other types of special lock. A locksmith will advise on suitable locks for metal doors and may also be able to fit them for you. A surface-fitting key operated bolt can be added to metal doors.

Sliding patio doors
Most sliding patio doors are supplied with a lock fitted to the centre stile, which prevents the door being slid open. However many do not have this facility and rely solely on the locks at the edge of the door, which can be easily overcome if force is used. In this case it is best to fit an additional lock to the top or bottom rail. You can do this yourself but great care must be taken; if you are in any doubt, it is best to have the lock fitted by a professional carpenter.

Timber sliding doors
There are several types of lock suitable, but these doors are best secured with hook bolt mortise locks which have a deadlocking action. You can use a lock with a claw bolt action which grips a recess in the striking plate. but these are not usually available with deadlocking function.

Interior doors
Doors inside the house offer a valuable second line of defence against the would be intruder, provided the layout is not open plan. In isolated areas or in situations where the house may be left empty for long periods, an intruder could cause considerable damage by smashing down locked interior doors. But since some insurance companies may insist interiors doors are left locked in this kind of situation, it is probably the best course to take. In any case. check your insurance policy before making a decision. The floor plan shows how locking interior doors can prevent easy access to the hallway and rooms on the ground and first floors. In most cases. the original locks fitted by the house builder will offer poor security. Here you can fit mortise bolts at the top and bottom of the door (to operate sideways on single doors)installing them with the keyholes facing the hallway.