"Nightjar" wrote in message
...
On 06/03/2019 19:39, Rob Morley wrote:
On Wed, 06 Mar 2019 18:46:07 +0000
(Alan J. Wylie) wrote:

I found this sliding patio door lock fitted on the house I've just
bought.

https://rfvt.org.uk/tmp/apprentice.jpg

I wonder if it would otherwise be possible to lift the door out of its
track (and off a normally positioned bolt).

The more usual approach is to fit blocks into the upper track, so that
there is only room for it to be lifted out when fully open.

Mine has the bottom wheels that you screw up with a screwdriver
inserted into the bottom rail of the door and you can only do that
with the door open, so burglars cant do that.