Can anybody recommend the best way to cover external pebble-dashed walls - altho' its more like grit-dashed with pieces of small sharp stone... looks c**p anyway! Hopefully, I'd like a smooth finish which I can then paint white. Can I just use standard undercoat and finishing plasters over the existing grit finish, or do I need something specifically for external use? And... would a coat of PVA on the grit help? Thanks guys!