Pebbledash exterior wall covering consists of a thin concrete coating with pebbles tossed onto it. The finishing process, used primarily in England and Wales to cover shoddy masonry workmanship, can be a difficult material to cover. The multiple nooks and crannies created between the pebbles is hard to reach when painting, requiring a specific painting procedure to ensure complete coverage. It's a time-consuming, as painting by hand is the only method of covering the pebbledash without over-painting and causing drips. The results may be worth it however, with the paint giving the old pebbledash finish a newly restored appearance.
Remove any dirt or debris from the wall with a water hose, washing the surface from the top down. Allow the wall to dry completely before continuing.
Brush the wall with a wire brush to remove any loose stones from the surface before painting in order to avoid ruining the smoothness of paint application using the paint roller.
Mask off any adjoining surface that you don't wish to get paint onto. Place a dust sheet along the base of the wall to catch any drips from the painting process.
Apply a stabilising primer solution to the wall, to seal the surface while at the same time creating a layer that the topcoat of paint will adhere to easier. Use a paint roller with a long-nap for flexibility over the pebbled surface. Roll the primer on in rows that overlap about 3 inches. Attach a pole extender so that you can reach the tops of the walls. Allow the primer to dry before applying the top coat.
Apply the top coat of paint using an exterior paint in two layers. Thin the first layer of paint up to 20 per cent before application. To thin the paint, fill an empty paint can about 70 per cent full of the paint and then add water to the paint while stirring with a wooden paint stick. Add enough water so that the mix is thin enough to drip easily from the stick without running off it in a stream. The thinning is necessary to get the paint into the small valleys created from the pebble covering.
Paint a wall beginning in the upper right corner of the wall and working your way leftward in overlapping rows. Use a paintbrush to apply the paint around windows and doors to ensure even coverage along edges. Brush a line of paint extending from the edge of these obstacles 2 to 3 inches wide, and then overlap the brushed lines with the paint roller.
Apply a second layer of paint without thinner two hours after the first, in order to give the first layer some drying time. Wait for the second coat of paint to dry completely before touching the wall surface. Drying times will vary depending on environmental conditions.