Mortar washing is a technique used to change the appearance of exterior brick. Brick masons mix a slurry of sand and cement to create a paste they sponge over bricks. A textured cloth, such as burlap, is rolled over the cement paste to create texture. If you have old brick on your home's exterior and are looking for a way to refinish it instead of replacing it, or if you have brand new brick that you'd like to infuse with Old World flair, then mortar washing is an inexpensive way to add a touch of fab to your home's façade.
Mix one part of cement to three parts of sand in the wheelbarrow. Add water slowly until the mixture becomes paste-like. The paste should not be runny since it will have to stick to the brick.
Set up the ladder where you are going to wash the brick.
Spray the brick that is to be mortar washed with water from the hose.
Trowel some of the mortar mix into a bucket. Position yourself on the ladder.
Dip a large sponge into the mortar mix. Apply the mix to the brick in an even coat to cover the brick. Apply more of the mix to some areas and not to others if you want to create a crumbled, Old World look. Work in small sections, as the mix dries quickly.
Roll up a burlap sack. Dab it over the wet mortar mix to create texture.
Repeat Steps Three through Six until you have washed and texturized all of the brick.