The exterior walls of my house mainly consist of pebble dashing. I plan to clean the walls as currently there is a small amount of red dye appearing (I think this is coming from the brickwork underneath). Plus the walls are just starting to get grubby with a little moss and algae.
Is there any specific products or techniques I can use to clean up the pebble dashing?
I doubt brickwork would leach through the typical 1" or more of mortar. It would have to be something near the surface.
A mild detergent with a mildewcide added should be sprayed on, allowed to soak per directions and then scrubbed lightly, followed by a rinse. If the red dye comes out, I would use a sealer to help the surface dry off more quickly after a rain and it will keep the walls cleaner.
