Did you know that exterior building cleaning of your building every 2-3 years can drastically reduce maintenance costs, extend the life expectancy of paint, and even reduce expenses for cooling the building?
The best benefit of an exterior building cleaning maintenance schedule!
The building will not only have a more appealing look, it will also prevent heavy biological growths which hold moisture and will slowly break down the buildings structure.
Identifying And Removing Stains Commonly Found On Buildings
When biological growths form on sealants they can break the bond of the material and allow water to enter. Once water enters the exterior walls of the building, two things happen. Mildew starts to grow inside the walls which is unhealthy for the occupants, and as the water penetrates back out to the exterior of the building, it brings mineral deposits with it, leaving staining behind on the exterior of the building as the moisture dries. Lime Run, also known as Carbonate Staining is a hard white or gray surface crust concentrated along a mortar joint or running down from a hole or separation crack between bricks and mortar joints.
What are the Black stains on buildings?
One of the most common problems we remove during exterior building cleaning jobs are black stains. The black stains on the sides of the building are usually caused by Hydrocarbons from vehicles and Jet Fuel, or from a Bacterial based algae called Gloeocaspa Magma. Gloeocapsa Magma is a species of Cyanobacteria. Cyanobacteria are an ancient line of photosynthesizing bacteria, which photolyze water generating oxygen gas. Ancient Cyanobacteria were ancestral to the chloroplasts of all plants on earth. Gloeocapsa Magma has gained notoriety in the Southeastern United States, but, it is also spreading throughout the Midwest. This particular type of Cyanobacteria is responsible for creating black stains and streaks on roofs. The bacteria accumulate over time as it feeds on moisture and calcium carbonate. This accumulation begins to show the black stains as the Cyanobacteria develop their dark and hard UV-protective outer coating. In most cases we use 200 PSI, 140 degree hot water, and an exterior building cleaning chemical called Powerhouse from Sun Brite Supply in Maryland, and sodium hypochlorite that is designed to clean buildings without using high pressure.
If you see uneven yellow or gold stains on the brick faces and in mortar joints it’s probably Acid Burn This is caused by cleaning the surface with Muriatic acid. The impurities in the acid are rapidly absorbed by porous masonry and when they are not properly rinsed off, the acid attacks the mortar and bricks.
Uneven white or gray stain on brick face or mortar joints. Often appears as vertical run marks. Does not disappear when wet. Cause: Inadequate prewetting or rinsing when cleaning with muriatic acid or other acidic solutions. Mortar dissolved by the acid is absorbed by the dry wall surface to produce insoluble silicate salts commonly referred to as “scumming.”
Tan, brown or gray staining concentrated along mortar joints of brown, gray or other manganese-colored brick. Cause: Manganese dioxide dissolved in rainwater, construction water or Muriatic acid. As water evaporates, manganese reacts with the alkaline mortar joint to create an insoluble brown stain.
Yellow, green or green/brown stains in the heart of light-colored brick units common in new or water-saturated construction. Cause: Water-soluble vanadium salts dissolve in rainwater, construction water or muriatic acid. As water evaporates, salts form on masonry surface to create unsightly stains.
Loose, powdery surface deposit that disappears when wet and may reappear as drying continues. Cause: Water-soluble salts dissolved in rainwater, construction water or groundwater. As water evaporates from wet bricks, it leaves the crystallized salts on the surface.
This post explains a few of the reasons why it’s important to create a schedule for exterior building cleaning, for more information about this, visit our exterior building cleaning service page.