Locksmithing and Security

Your insurance policy might ask for for patio doors, etc. to be fitted with mortised rack bolts. Unlike the most obvious kind of bolts which would be fitted to the face of the door, mortised bolts are fitted within the door itself. From the outside all you see is a little hole into which you put your “star” key and which you then turn to extend or withdraw the bolt.

Rack bolts are very strong but there are a couple of points you should bear in mind.

Keep an eye on your builder and check that they don’t drill the key hole right the way through, as on one door I saw the other day! The whole idea is negated somewhat if there’s a keyhole on the outside!

Although they are strong when deployed, their winding mechanisms (the “rack”) are not strong. If you can’t operate the bolt with light finger pressure, stop. If you force it, you will strip the teeth off the rack. If that happens in the locked position then you will face an expensive exercise getting it open again. If the door is warped or swollen, try relieving the pressure on the bolt by gently pulling on the door handle while trying to wind the bolt in or out. If it’s getting more and more difficult to operate, get it seen to before it breaks.

No more than a couple of turns of the key are needed. Any more and, again, you will tend to strip the teeth. Try it with the door open while feeling or watching the bolt; note how many turns are needed.

If your rack bolts are fitted to windows, they might be the short variety. These aren’t much good as the bolt is so short. If you have to fit these (usually because the frame is too small for the regular size), make sure they aren’t recessed any more than they need to be. Recessing is when you chisel a shallow depression in the door edge for the bolt’s faceplate, and in the frame for the keep. I recently visited a property where there was already a 3 mm gap between the window and the frame, and where the fitter had gone on to recess the bolt and the keep each by 2 mm more than needed. Result? The bolt wasn’t actually engaging at all!