Stucco weatherproofs and hides an exterior brick wall's imperfections. Stucco, a cement-based wall covering, bonds to the brick's pores and fills its mortar joints. An exterior brick wall covered with stucco uses a base coat and a finish coat. The base coat, sometimes called a scratch coat, protects the brick wall from the elements and provides a smooth surface for the finish coat. The finish coat gives the stucco its texture. Before applying stucco to a brick wall, repair all damaged brick mortar and reinstall any loose bricks.
Things You'll Need
- Pressure washer
- Plastic sheeting
- Masking tape
- 3/8-inch wood lathe
- 1/2-inch concrete stub nails
- Concrete bonding agent
- Paint roller
- Backpack sprayer
- Concrete mixer
- 12-inch flat trowel
- Straight edge
- Plaster rake
- Foam float
- Whisk broom
Clean the exterior brick wall with a pressure washer. Remove all mold, vegetation and other debris from the brick's surface.
Cover the windows and doors in the exterior brick wall with plastic sheeting, using masking tape to hold the plastic in place. The plastic protects the windows and doors from unnecessary damage.
Mount a strip of 3/8-inch wood lathe to the top and bottom of the exterior brick wall. Secure the lathe to the brick wall with 1/2-inch concrete stub nails, using a hammer to drive the nails.
Apply a concrete bonding agent to the brick's exterior surface according to the manufacturer's instructions. A bonding agent is typically applied with either a paint roller or a backpack sprayer.
Mix a batch of pre-mixed stucco with water in a cement mixer, using the stucco manufacturer's instructions for a scratch or base coat. Pre-mixed bags of stucco contain the necessary ratio of portland cement, sand and lime. The manufacturer's instructions include the amount of water needed for a base coat and the amount of time needed to completely mix the stucco. Base coat stucco should have the consistency of toothpaste.
Apply a 3/8-inch-thick layer of stucco to the exterior brick wall, using a 12-inch flat trowel to spread the stucco mix. Hold the trowel at a 45-degree angle to the wall and press the stucco mix into the brick's mortar joints. Let the stucco dry for 15 minutes before continuing.
Hold a straightedge between the 3/8-inch lathe on the top and bottom of the wall. Work the straightedge across the exterior brick wall, removing all high spots in the base coat. Fill any low spots with the leftover base-coat stucco mix.
Remove the 3/8-inch wood lathes from the brick wall, using the hammer to pull the nails. Fill the strips along the top and bottom of the wall with the base-coat stucco mix, using the 12-inch trowel to apply the stucco.
Smooth the base coat's surface with either a plaster rake or a foam float. Remove all of the tool marks from the stucco's surface. Let the stucco's base coat dry for 24 to 48 hours.
Mix a batch of pre-mixed stucco with water in a cement mixer, using the stucco manufacturer's instructions for a finish coat. The finish coat should have a slightly lumpy consistency.
Apply the desired finish coat to the stucco covering the exterior brick wall. Dip a whisk broom in the finish coat material and toss the stucco mix against the base coat. Practice in a small area until achieving the desired effect.