I have a new build property with a set of upvc french doors. The local crime prevention officer has said they are the weakest point of security and explained how they can be broken into within a matter of seconds. He recommended I fit some sash jammers.
However, I'm totally clueless as to what to do. The doors aren't the best, and I cannot find any screw/bolt that will actually hold any lock with any decent resistance as there's hardly any thickness of the plastic/metal to grip to. Any ideas would be great - even a local locksmith said there's nothing extra that can be done.