I've cut a channel in my wall to contain a mains lead and HDMI cable for a projector. The HDMI cable is quite thick so I've cut down into the cement render, so about 12mm at its deepest. Looking at B&Q I'm not sure whether one-coat plaster or finishing plaster would be best. I'm guessing one-coat would be stronger in the big gaps (more like multi-purpose filler) but give a rough finish. Conversely the finishing plaster would be more likely to crack but give a good finish without the need to sand.
Does this sound right? Or is there a better product to use?
Does this sound right? Or is there a better product to use?