Julian Cassell's DIY Blog

Mortice door bolts fit in the edge of doors providing an excellent extra security measure. Normally, bolts are positioned on the opening edge of the door – one close to the top of the door and another close to the bottom. They may also be used on the hinging edge. The bolts are key operated from the inside, and cannot be accessed from outside. read more »

Five-lever locks are used for entrance, and back doors – five levers approved to BS3621 is the minimum requirement for entrance doors. Mortice lever-locks can have between 2 and 7 levers. The more levers there are, the more difficult the lock is to pick. Fitting a mortice lock from new requires drilling into the edge of the door in order to accommodate the lock (using a similar technique to that shown for fitting a latch in the guide ‘Fitting internal doors’). read more »

Cylinder locks generally require changing when you move house, or another common situation is if you lose your keys. A typical variety of cylinder lock is the Yale lock shown below. These locks may literally be changed in a few minutes – its really not necessary to hire a locksmith or carpenter, and unless there is a problem with the lock body itself, you literally just replace the cylinder part as shown below. read more »

Ask the experts

Burglar-proof Victorian door

The Guardian, Saturday 19 September 2009

How do I make a Victorian front door burglar-proof without resorting to a grille or screen? read more »