We have just had our loft done and i am wanting to fix a rail for our blind that is to fit over double french doors and is therefore going to be quite heavy. I am unsure what to use to drill into the wall as we have previously drilled self tapping screws for plasterboard elsewhere but they have loosened within a few weeks and fell out of the wall leaving a gaping hole. I am pretty sure there is a wooden beam behind the plasterboard but don't know if there is a gap in between.
Has anyone got any suggestions on how i can do this without ruining the wall or have the blind fall off in a few weeks??