Locksmithing and Security

Close on the heels of the plea not to choose uPVC doors, comes a story of 14 uPVC windows.

The manufacturers of these accursed uPVC products tend to discontinue them after only a few years. And whereas wooden doors and windows can be kept in service for twenty years or more, once your uPVC window or door has failed (and it will) you won’t be able to repair – only replace.

I’ve just been to a job where the keys to the espag handles (espangnolette handles) on the uPVC windows were lost two occupants ago. Yes: the manufacturer has discontinued them and I can’t even get a key blank. All 14 handles will have to be replaced.

I’ve just returned from a visit to a door that’s five years old and is going to have to be replaced.

So, it’s time for my regular plea to any of you chosing a door. Although, pricewise, a uPVC (or aluminium) door and frame with a multi-point lock strip (MPL) might initially seem a good idea, it will go wrong and sure as eggs are eggs, replacments for your MPL strip will no longer be available. And, no, you can’t usually replace parts of a strip; it’s all or nothing and anywhere between £60 and £200 in parts costs.

If you have a nice wooden door with a good latch lock and a good deadbolt it will last longer. It can be painted when you get fed up with the colour. When the weasels find a way to defeat your locks you can replace them or augment them with better ones. When the locks eventually wear out you will be able to find replacements rather than having to butcher the door in order to fit a second-best alternative MPL or having to replace the entire door.

If you have a uPVC door you’ll have none of the above flexibility.

Many insurance policies ask for a mortice lock on the final exit door — the front door for most of us. This is because you can’t bolt the final exit door from the inside if you’re going out, and a rimlatch isn’t particularly secure. (A rim lock is fitted to the face of the door and a mortice lock is fitted within the door.)

So a mortice lock makes sense. Unless, that is, your door isn’t thick enough. To get a mortice lock into the door, you need a hole (the “mortice”). If your door is less than 44 mm thick, then the hole for, say, a Chubb lock weakens the door more than the lock strengthens the door.

(There’s another problem, of course: PVC doors are becoming more and more common, but insurance company personnel aren’t becoming any more intelligent. Many insurance policies don’t consider the completely different locking regime of PVC doors)

Thin doors often come about when Bodgit & Rakeitin carry out a conversion of a house into flats and fit internal quality doors for the flat doors.

What do you do if your insurance company insists that you weaken your front door? Change your insurance provider for one that isn’t exclusively populated by bean-counters and where there’s actually someone who is knowledgeable about security.

And if you’ve got a door that’s hovering around the 42 or 43 mm thickness and it already has a mortice lock, you have to ask yourself if it’s wise to add another mortice lock and put another big hole in it.

I mentioned elsewhere, a front door around where I live, fitted with three high security locks. Yesterday I came across a tiny, insubstantial shed door, where the same triplet of locks had been fitted, two of which were mortice locks!

I had a little rant about uPVC doors a few posts back. Well I don’t much like the cylinder that often goes with it, the euro-profile cylinder.

When lever locks wanted to be operable from both sides, the clever engineers at companies like Chubb thought carefully and insightfully about key symmetry and key differs. If you have a 5-lever mortice lock key and take a look at it you’ll see that it’s symmetric and that it has not 5 positions, not 10 positions but 7 positions (bittings they are called). (Unless you have an uncommon lock like a Securefast, Walsall, or one or two others.)

The first and third levers, counting outwards, are the same. This means that a reasonably short key can be used from both sides and still have enough lever variation to allow over a thousand different key possibilities. (If we call the levers A,B,A,D, and E, then a key that is EDABADE can operate the lock from both side while only sacrificing one lever’s worth of variation.)

When some miserable creature and their miserable company somewhere wanted to use a cylinder lock (like a “Yale”), rather than a lever lock, and also to be able to use the same key from both sides, they simply doubled the thing up and had a complete cylinder at either end. Well that’s not too bad — modern manufacturing can waste materials very efficiently; and with, for example, the Swedish profile cylinder system, it can be well designed and still quite secure. However, it requires two minutes more work to fit or change a “Swedish” cylinder, so this miserable creature (does anyone know who it was?) made a one-piece, double-ended cylinder — the euro-profile — the one that’s shaped a bit like an upside down exclamation mark. And when I say “solid”, it’s only just solid. Through truly stupid design, it’s actually very fragile in one very critical place and moderately fragile in others.

And because it’s one piece there are twenty different sizes to stock; and stock twice because you need to have them in brass and in nickel finishes.

And although this awful, wasteful device is the way it is in order to allow a key to work from both sides, if you accidentally leave a key in the inside half when you go out, you can’t actually use another key from the outside if the inside one has turned a little.

And — finally getting to what prompted this moan — if one of these things is fitted in a typical 45 mm door, their having duplicated the entire damned mechanism means that you can normally only get 5 pin tumblers each side unless you use a bigger cylinder than necessary, sticking out like handlebars, but allowing you to get a more secure 6 pin tumblers each side. So there’s no way for me to give one of yesterday’s customers what is needed.

So why don’t the States and continental Europe, and increasingly the UK, carry on fitting mortice deadlocks? Well it takes a bit more work as you have to chisel a nice neat, but quite large, hole in the door, if you’re fitting the lock later on in the life of the door. Or it’s more difficult and more expensive to manufacture if you’re mass producing doors. And perhaps, a lever lock key being longer and heavier, only the pockets and handbags of the UK of the previous century were up to carrying them.