Screws that normally fix the vent in place can't do their job anymore. The drywall has crumbled to the point that the tapped hole for the screw lacks a boundary with the duct. (Picture attached.)
- The cutout for the original vent larger than necessary, forcing the screws to be closer to the duct than is optimal?
- The original installation should have used some sort of plug so that the threads of the screw didn't compromise the integrity of the drywall so easily?
How would you:
- (a) go about fixing this?
- (b) prevent this from happening in future installations?
The issue, in an image: