What is a sash window lock?

Any lock fixed to a vertical sliding sash window whether made from uPVC, timber or aluminium will use a sash window lock. They can be fixed as pairs or single locks depending on the size of the window. Many people refer to the sash lock on older timber sash windows as fitch fasteners, sash fasteners, brighton fasteners, cam locks, claw fasteners or quadrant fasteners, to name a few, but not window handles as these are generally casement type fittings.

How easy is it to fit a sash window lock?

Generally it is very easy as long as you have the correct parts. In the case of uPVC and timber sash windows the sash lock will be fixed to the window using self-tapper type screws. In the case of aluminium you may well have to consider rivets along with special keep/catch plates for some very narrow frames to get adequate fixing. The general rule of thumb is to replicate the existing fixing method when replacing sash locks.

Can I get sash locks that leave the window open but locked?

In some cases you can leave the sash slightly open provided you have the correct keep/catch. The amount of 'night-vent' opening that can be achieved is very small but care should always be exercised with regard to security if using this position.

I'm concerned about child safety so how can I child-proof a sash window?

There are ways that you can restrict the opening of the window and this would be very sensible considering the safety concerns of a fully open sash window above ground floor. In all cases where safety is important you need to carry out your own risk-assessment, but there are products available that will help improve the safety of a window whether timber, uPVC or aluminium.

In the case of timber sash windows you can easily put two roller stops into the top sash to avoid the bottom sash going above a certain height without the use of a key to release it. Such sash window stops can also be removed entirely or placed in several positions depending on the needs of the individual.

PVC sash windows are a little more difficult to fit restrictors to but some restrictor devices are available such as the SW10 sash restrictor which is a thumb and key action restrictor.

Aluminium sash window restrictors are the most difficult to find and to fix requiring the use of rivets in most cases for a stronger fixing.