kitchen backsplash

Question regarding the drywall prep if necessary. The bottom 4" of wallboard was damaged when previous laminate backsplash was removed. The granite countertop is in and I am ready to tile. Do I need to fill and level that bottom area? Should I just put up a 1/4" backerboard? Just spread the mastic thick?

Concern with 1/4" backer is the thickness at the ends where I will be using Bullnose.

The pros here steered me straight when I did my bathroom floors and shower, which seemed much more critical to get correct (H2O).

Thanks for help!

If the damage is minor, I would use a little extra mastic. You could apply drywall mud and sand it smooth but it may not be worth the trouble.

Repair the drywall first using joint compound, or Plaster of Paris, or spackling.

DO NOT apply extra mastic, it will never dry properly.

You could use thinset mortar which would also work for the repairs and would dry overnight but don't build-up the mastic.

Mesh tape, thinset then tile.