My walls have no cavity, they are solid and 12" thick. There are random chunks of flint buried inside them so it's pot luck as to whether you can drill into the location you attempt because if you hit a flint then all you do is heat up your drill bit until it glows.
Yes, I read that the first time. It was the description of the window in a 6 foot, grill covered hole that set me thinking. If I'm wrong then fair enough. I'm off to bed. Hope you get it sorted out, my friend. Good luck.
@TrevorPH Just a thought. Would you be able to run perhaps a small diameter flexible tube - effectively a duct - along the route from the external splicing point ( CSP) to where you’d like the ONT to be? If you leave a drawstring in there, all the OR engineer would need to do is pull the fibre through. Making sure of course that any bends are not too sharp. A £2 coin could be used as a rough guide of the minimum bend radius. Others have used hose pipe within hollow walls quite effectively too..
