Even though there are various makes such as Chubb, Union etc we tend to use the term "Yale" as a generic description. Much the same as "Hoover" covers many makes of vacuum cleaner. The lock part on the door is called the Rim Lock and the part on the door frame the staple. They were designed to keep the door closed but were never intended as a Security device. In fact if your door has just a Yale lock then it would be very easy for a burglar to break in by sliding a piece of card ( known as a Loyd) in between the door and frame to push the latch back.
To overcome this inherent weakness an autolock was designed. It has a small lever above the catch and when the door closes it is depressed and locks the catch in position so it can't be pushed in. This is a more secure design of rim lock and one that we would recommend but the weakness is in the staple. Usually held in place on the door frame by two screws one above the staple one below and a third going into the frame from the back. The problem is the two side screws are close together and can split the grain.
A force applied to the lock by lever or shoulder charge could split the wood in the frame and the whole staple can be prised away and the door opened. A London Bar is a strip if metal that supports the back of the staple to reinforce it against pressure. They are available from many outlets, especially Locksmiths.However the Bar needs to fit up snug against the staple and buying on line there could be quite a gap and that would be totally ineffective.
I have seen Locksmiths quote £50 to fit one and the ones you can buy on line can cost from £20 upwards (but will it fit snugly). Here I have made one for under £5 with basic DIY tools that took me just under an hour to make and fit. Here's how.
I bought a meter of 15x 22mm strip aluminium from a large DIY chain for £2:51p and a small packet of pan head screws £2:40.
Here is the lock I was reinforcing. The distance between door edge and frame was excellent and the staple screws were tight and firm but it had been cut very deeply into the frame and very near the edge.
First thing was to make a simple template with a strip of cardboard to the shape to show where the bends would be. Aluminium does not like being bent at 90 degree right angles so be careful when bending.
How long you keep the strip will be down to you but I allowed 18cm above the top edge of the staple and the same from the bottom edge.
Using the template I put a bend in the strip and offered it up to the door frame and kept putting a deeper bend in until I reached the desired angle.Then I held it in position with a pair of mole grips.
Using a piece of flat wood force the strip against the rear of the staple. Once flat against the staple push the edge of the wood in towards the door frame. This will give you a fairly close guide for the bends
Some gentle bending and placing over the staple until it was the right shape
Put the very top screw in, just nip tight and then the first hole below the staple but do not tighten, leave a little loose
I drilled the holes either side of the bends at 2cm and spaced the rest at equal intervals both above and below
On my piece I had four holes above and four below so will number them 1 through to 8 starting at the top. Screw 1 was the first "nipped up" and then screw 5 only screwed in half way. Then put screw 2 and 3 in, again just tight followed by 7 and then 6. Using this sequence you will be pulling the strip into the frame. Finally put in and tighten screw 4, this will pull the top strip in tight to the top of the staple and finally tighten screw 5.If you are happy with the fit you can tighten the screws fully, 1,8,2,7,3,6,4 and 5. Here you can see the strip is up nice and snug against the rear of the staple. I will remove and spray the strip and screw heads with white enamel spray paint to make it look nice..
Although aluminium is not as strong as steel this brace will certainly add a great deal of resistance to any outside pressure. I have used steel in the past but it requires a lot of heat applied to bend the steel to the proper shape. This version, in easy to bend Aluminium, to my mind, is certainly strong enough to do the job.
A couple of words of warning: Aluminium doesn't like being bent again and again so make each bend bit by bit and offer it up to the staple often to get the right shape. Trying to straighten the aluminium several times will make it weak and start to tear. Take your time to get it right.
Use Pan Head screws as countersunk screws will bite into the Aluminium and weaken the hole so it would tear and lessen the strength and resistance..
I hope you found this DIY tip usefull. If you have any comments or questions please drop us a line