Wall behind bathroom mirror

Hey everybody,
My wife asked me to replace the mirror in one of our bathrooms. I was able to take the old one down -- it was glued to the wall; see attached photos.

The new mirror will be attached with screws. So my question is what should I do before painting and hanging the new mirror.

You can see some of the black glue left. I will scrape this off. My biggest question is the spot where some of the drywall came out. Do I need to fill this? To prevent mold? Anything else I should do before painting?

Thanks for the help!
- Jay

 

If it's going to be covered up you really don't have to do anything to it other than prime it before painting. If you want to patch the damaged sheetrock you can paint the area first with an oil based primer or Gardz primer, and then repair with sheetrock compound. Painting it with primer first will help prevent moisture in the compound from lifting the damaged sheetrock paper.

If you choose not to repair the sheetrock damage, I would still prime as above before painting as the moisture in latex paint can also lift the damaged sheetrock paper.

If you have a heat gun or hair dryer, warming the old adhesive may make it easier to remove with minimal damage.

 

Great. Thank you very much!