What's your best product for a single coat of protection on external brickwork to prevent rain penetration and yet leave the brickwork looking exactly the same after drying out?
Assuming the brickwork is bare, clean, dry, sound and prepared as detailed in the technical data sheet we can recommend Wethertex WB1 WeatherBLOCKER.
This is clear and can give protection from damp without effecting the appearance of the substrate.