Small bits of roughcast from my garage and porch have fallen off exposing the brick behind. Other bits are not very sound as when i lightly tap it i get a hollow sound so i reckon it needs to come off. Id like to repair it myself but im not sure what i need to do the job, is it just a cement type mixture? The existing roughcast is greyey/cream colour in a sort of rippled effect, not pebble harling.
TIA
Doug