Photo showing a wall of pebbledash, straight from the 1930s. Pebbledashing (roughcasting) was once a popular way to finish off the outside of houses, being cheap and easy to carry out. The pebble dash walls were simply covered in a plaster, which often included sand and cement, and then the pebbles are mixed into a slurry and thrown or 'dashed' at the top coat of the render, where they provided a strong surface against all weather.