About Stains on Bricks

When you build or pave with real brick, you can be sure you are using a durable, solid material. Brick provides insulation and stands up to years of use. However, brick succumbs to stains over time. You can clean and care for your brick so that it looks good for years to come.

Significance

Brick has primitive roots. Brick-makers essentially create the blocks much as they did thousands of years ago by molding clay and sand into block shapes and baking it to a rock-hard consistency. Because bricks are made of dried clay, the material is porous. Manufacturers and installers sometimes protect brick with sealant, which helps resist many stains and is easier to clean. Other producers leave the brick unsealed. These surfaces collect and hold dirt, grease and grime more tenaciously.

Types

A number of causes can result in stains on brick. The cause of the stain will determine how you clean the bricks. Time and the elements can cause moss and rust stains. Exposure to smoke, paint, oil and tar are other common brick stain origins. Colored stains, such as powdery, white efflorescence and brown or green stains caused by chemicals used to make the brick are also frequent blemishes.

Considerations

Moss and algae grow on brick in regions with excessive rainfall. This slippery growth can be dangerous on brick sidewalks or driveways. Make a solution of diluted bleach--about 1 part bleach to 5 parts water--to kill moss and algae. Scrub the area with a stiff nylon brush, and follow up with algaecide. Paint stains adhere to porous brick and can be the most difficult type to remove. Try a commercial paint removal product and steel wool or a wire brush.

Prevention/Solution

Trisodium phosphate, commonly known as TSP, is effective on many types of brick stains. You can find TSP at your local hardware store, generally in the paint department. Combine a pound of TSP with a gallon of water. If the mixture is not pastelike, add powdered chalk until it reaches a thicker consistency. Using a paint stir stick spread a 1/2-inch layer of the mixture over the stain. Allow it to dry completely, and remove with a wooden paint scraper. Rinse with water.

Potential

Make your brick more stain-resistant by sealing it. Clean the bricks thoroughly before adding the sealant; otherwise, the stains will become permanently preserved under the sealant. Allow the brick to dry completely, which may take several days. Purchase a clear masonry sealer and paint it onto the brick area. Protect any surrounding areas before you begin. After the first coat dries, add an additional coat. The sealant will wear away over time, so apply one coat every year for best results.

Resources

• Natural Handyman: About trisodium phosphate