Have a 9cm Diameter Hole from AC removal I am patching today + patching from old screw holes.
Plan is for the interior to fill with Earls Expanding concrete, then UniPro Multipurpose Filler - Sand and Paint.
Was going to apply the same process to the screw holes or it that overkill with the multipurpose filler being sufficient?
How long should I wait after applying the expanding concrete before the filler?
On the outside I was just going to messily shove a brick with some of the expanding concrete in there and then cover with a vent to make neat (see vent below).
Will post progress pics just seeking advice/comments - thankyou

