I'd go with 12mm, elongate it, then use polyfiller to fill the space in around it. Just don't screw anything into it
Change of plan - no drilling involved. Just going to fill the whole box with pink Gripfill and stick it to the wall. For the door bar I'm just going to use duct tape, should hold it just fine against a load of thugs breaking in to steal a load of jewellery from an 83-year old woman.
What are you, one of these "Do It Yourself" types, spent too long watching home improvement programmes on the TV? Pfffft. Amateur.
Yeah, I did catch about 2 seconds of one of those once. Way too long. I put something up on an external wall at work with velcro recently and it hasn't fallen off yet. Admittedly it was just a laminated sheet of A4.
10mm plugs, with 10mm drill and 10mm anchor bolts. The type used by Sky to stick up their dishes!!! (odd that I get them for "free") Nothing ever comes off the walls in my house although the wife did question my methods putting up some dainty tealight holder thing. I told her to do it herself next time