Sorry if this is the wrong forum please move if it is.
Please bear in mind i am rubbish at D.I.Y so basic explanations of a fix would be greatly appreciated.
We have a very steep staircase and a banister that runs the full length this is fixed in place by 3 brackets, each bracket has 3 screws that hold it to the wall unfortunately because the walls are rubbish and there is so much plaster the middle bracket eventually comes loose (this is the third time in 4 years - not exactly an emergency but would like a next step) i have moved up to 8mm screws (the biggest the existing holes will take) with the plugs that came with them but i have a feeling in a few months it will have come loose again, could anyone suggest a fixing that can go deeper into the wall and are more likely to stay put, i can enlarge the holes in the brackets a little if needs be.
Thanks in advance for any advice you can give on this.