I am mounting a projector on the ceiling in my single story extension with a sloped roof.
My luck had it that there was a joist within range and I proceeded to drill into it from below through the plasterboard ceiling and fix the bracket as I thought this would be the best support.
Now, afterwards, I am concerned that I have weakened the joist and that it may become an issue.
I have attached a sketch that shows approximate dimensions.
The projector and mount will be approx. 13-14kg (28-31lbs) max. In weight.