There's good news for homeowners who would like to install stone veneer on their homes and already have stucco exteriors--stucco is one of the better exterior surfaces on which you can install stone veneer. Because of stucco's cementitious properties, it will provide the bonding needed to secure the veneer to the exterior wall surface. This will allow you to have the natural stone look you prefer, without having to use a scratch coat that might otherwise be needed. To install a stone veneer on your stucco walls, use the information you'll find below.
Step 1 - Clean Your Exterior Walls
Use a garden hose and masonry brush to clean the exterior wall on which you plan to install your stone veneer. Loose dirt or debris on your stucco wall can prevent the mortar used on your stone veneer from bonding to the wall surface, so be sure all dust and debris are removed.
Step 2 - Mix and Apply Your Stone Mortar
With your electric drill and a mixing paddle attached, mix a batch of mortar in a clean 5-gallon bucket. Use your brick trowel to apply your mixed mortar to the rear surface of your first stone. Press the stone in place on the bottom of your stucco wall. While turning the stone back and forth slightly in place, press it onto the wall with enough force that a small amount of mortar is squeezed out from behind the stone. Apply additional stones, forming the bottom row of stones.
Step 3 - Level and Clean off Your Stone
When you've added the last stone on the bottom row, use your level to be sure this first row is level. To make all other rows level, it will be important to make this bottom row level. Make necessary adjustments to level all stones in the row. Hold your level against the stone surfaces to be sure each stone surface is evenly placed on the wall surface. Before proceeding to the next row, and before the mortar dries, use a damp sponge to remove any excess mortar. When your sponge becomes filled with mortar, rinse off the excess mortar with water.
Step 4 - Mix Your Grout
Follow mixing instructions on your grout package, and use your electric drill and a clean mixing paddle to mix your grout in a clean 5-gallon bucket. From this bucket, take enough grout to fill your grout bag about 75 percent full.
Step 5 - Apply Your Grout
To adjust the grout bag opening to get the right size grout flow, pinch the bag's opening as the grout leaves the bag. By squeezing the bag you will be able to push the grout out of the bag and into the cracks between the stones you've applied to the wall. Use a grout tool to smooth this grout, working your way across the wall. When finished applying the grout, use your sponge to clean the stone and remove excess grout