Stucco is a mortarlike coating applied to a house’s exterior to create a strong, long-lasting, weather-resistant coating that can be painted or allowed to weather naturally. While stucco can be applied directly to many surfaces, for maximum durability a specially designed backer board is usually installed against the existing wall.
Things You'll Need
- Tape measure
- Utility knife
- Power screwdriver with Phillips-head bit
- Coated backer-board screws
- Cement bonding agent
- Finishing trowel
- Plasterer’s rake
- Brush or sponge
Measure and cut backer board to fit the application. Score the backer board with the utility knife, place the scored line on a hard, straight-edge surface, such as the edge of a board, and push to snap off. Finish cutting the paper backing with the knife.
Attach the backer board with backer-board screws and a power screwdriver. For exterior walls, install backer board over foam-sheet insulation. Make certain the screws go at least ½ inch into the wall, past the board and sheet insulation.
Apply a cement bonding agent to the backer board and allow to dry according to the manufacturer's instructions.
Mix the stucco according to the manufacturer's instructions and apply a primary “scratch” coat with a trowel. Work in a straight line, one wall at a time, to minimize lines. Allow it to harden slightly and finish by smoothing with a plasterer’s rake. Allow the scratch coat to cure for 48 hours.
Dampen the scratch coat and apply final ¼-inch-thick finish coat with the finishing trowel. Texture as desired with a brush, sponge or trowel. Allow at least six weeks before painting.