I've had all the locks changed at our apartment but whilst he was there the locksmith explained that the double gated security grills at our French doors are about as much use as a chocolate fireguard. Even with the top and bottom bolts secured and the central lock locked it only took him about 15 seconds to get the doors opened. Armed with two screwdrivers it's a simple task to prise open the right hand door with one screwdriver and get the second screwdriver inside to push the bolts open. When the top and bottom bolts are disengaged then you only have to pull the doors open and they will swing out enough to disengage the central lock. It honestly took him no more than 15 seconds (with very little effort and no noise) to get our security grills opened. The solution is to buy two bolts, the type that are used on garden gates and which have a padlock to stop the bolt being drawn back (you can get them from the local Yapi Market for about 7tl each) and fit these to the inside of the left hand door at the top and the bottom. For extra strength I drilled a hole into the concrete lintel at the top and the terrace tile at the bottom and fitted the bolts such that they protruded into these holes. Now, even if they bolts on the grill are opened you can't open the locked gates as the bolts prevent the doors from being swung forward.
