Stains form on buildings from a variety of issues. Understanding what’s causing a particular stain requires a bit of investigation. What color and appearance does the stain have? Where is it showing up? What kind of material is it on? How much moisture is in the area? Keep reading to find out about common stains that develop on buildings.
Rust: Rust occurs through oxidation, a chemical reaction that occurs when iron encounters water and oxygen. On a building, rust occurs when you have metal fixtures exposed to the elements. Some chemicals, natural minerals, and temperature fluctuations can increase the rate of rust formation.
Iron Staining: This is typically the product of metal embedded in a structure and often appears like a stain in the mortar joint.
Manganese: Often found on red or tan brick, this staining occurs when manganese oxide reacts to acid. When bricks are exposed to water, the interaction can leave behind a stain. Manganese oxide is a common coloring component, and the manufacturing process often includes acid, so this is not an uncommon stain.
Salt Efflorescence: The product of salts evaporated on the surface of porous materials; this ‘bloom’ often appears white but can vary based on the salt left behind. Most commonly found on brick, it also shows up on stucco, block, concrete, and even wood occasionally. The presence of efflorescence may indicate an ongoing water intrusion. So be mindful if, even after cleaning, it becomes a persistent problem.
White Scum: Also known as calcium silicate, white scum is the product of new masonry cleaner, misused, interacting with brick. The insoluble salts result from the reaction leaving behind unsightly white or grey stains on the brick face or mortar joints.
Calcite: Calcium carbonate is left behind as a thick white deposit that develops over time when water passes through mortar joints. As the water evaporates, it leaves behind white deposits.
Vanadium Salts: Vanadium is a mineral that occurs naturally in some clays, often lighter/buff-toned clay. When these clay bricks encounter unbuffered muriatic acid or an excess of water, chloride salts of vanadium may form. As water evaporates, it leaves behind a deposit that often appears green or yellow.
Organic Matter Stains
Mold, Mildew, Algae, Moss, and Lichen – These organic growths can cause stains that appear green, black, or red, depending on what is growing. To grow, they typically require a steady supply of moisture. It’s essential to use the correct cleaning method to remove organic matter, as harsher methods may not be necessary and could damage the underlying surface.
Why Do Some Building Materials Seem to Attract Impurities?
Brick and stone contain natural minerals and salts that can leach and react with moisture in the air. Sometimes that process is accelerated or created by the presence of cleaners or common solvents used in their manufacturing process. Another reason why stains frequently appear on some surfaces is the presence of excess moisture. If a stain keeps reappearing after cleaning, it’s worth further inspection to ensure it’s not a sign of an underlying structural issue to address.
What Method Should I Use to Clean Stains on Building Surfaces?
There are two critical considerations to determining the proper cleaning method for your building stains. The first is what caused the stain and what material the stain is on. You’ll need to understand the root cause to know what kind of cleaning method will best remove the stain. You want to aim to use a cleaning method that won’t be too harsh on the underlying surface and cause permanent damage to your walls or structures.
A third consideration is that some stains indicate a more severe problem. Stains can indicate a structural issue causing an excess of water to form where the stain is appearing.
Hand Cleaning: For some stains, you can tackle them yourself with a soft-bristle scrub brush and dish soap diluted in a bucket of water. Address mildew stains with a mix of 3.8 L water, 1 L bleach, and 29.6 mL dish soap. Remember to protect your eyes and hands while handling bleach, and do so in a well-ventilated area. While it might feel wise to use stronger cleaners, these can cause damage to people breathing, some building materials, and the surrounding plant life.
Pressure Washing: Some stains require more heavy-duty cleaning. Note that power washing can damage structures, particularly if the material is soft or weakened. Call the professionals at Squeegee Squad to assess the stain and effectively clean your building without damaging delicate surfaces beneath. We use environmentally friendly cleaners to effectively remove rust and other stains (upon request). Using the appropriate pressure washing techniques and the proper application of the solution allows us to clean a wide variety of organic and chemical stains.
Soft-Washing: This process involves applying a biodegradable cleaner that can tackle most stains and mildew, followed by a low-pressure soft-wash that is safe for even delicate building materials. Soft-washing also stays clean longer and will continue to clean the exterior with every rain.
How Often Should I Clean my Building?
If stains are becoming bothersome, it’s evident that it’s time for a cleaning. What does a good cleaning schedule look like on an ongoing basis? Usually, it’s worth doing a thorough exterior cleaning every six months. It’s not just a matter of appearance, either. Regular cleaning will protect your home or business exterior from issues that can damage surfaces. Plus, the cleaning process will remove eggs, cobwebs, and other insect debris. The professionals at Squeegee Squad will have your building sparkling in no time!