Building managers often notice a chalky, white substance that sometimes appears on exterior masonry walls.
Known as efflorescence, it occurs when water evaporates and leaves behind salt deposits on the surface. It is one of the most common facade maintenance issues that can degrade the value and aesthetic quality of a commercial facility.
Efflorescence affects almost every type of masonry, according to Roger Krick, Director of Facade Services for Mid America Specialty Services. It shows up on brick, granite, marble, stucco and other natural stone surfaces.
Technicians often find efflorescence near water fountains, steps, leaking pipes and other areas that are vulnerable to excess moisture. It also appears on basement walls in moist environments and may have a white, brown, yellow or gray color.
What Causes Efflorescence?
The appearance of efflorescence, Krick explains, is a symptom of moisture seeping out from underneath the substrate, or facade surface. Water passes through porous building materials in a process known as capillary action. Salt and mineral deposits are pulled out by the moisture and left behind as the water evaporates.
Where does the salt come from? In many cases it is already present in the brick, cement, grout or other building materials at the time of construction. The exterior wall may come into contact with salts found in moist soil near the ground. Salts that cause efflorescence may also be more common in geographic areas with hard water.
The appearance of efflorescence varies according to the soluble materials and atmospheric conditions unique to a building’s location. Common culprits include water-soluble sodium, potassium and calcium. Weather conditions such as temperature, humidity and wind also make a difference. Efflorescence often forms more quickly during cold weather, when slower evaporation promotes the migration of more salts to the exterior surface.
Can Efflorescence Be Prevented?
The key to controlling efflorescence, Krick points out, involves preventing water from accumulating between the exterior facade and interior wall. This can be accomplished by installing moisture or vapor barriers under the substrate. It’s also essential to repair leaky pipes and cracks in the wall as quickly as possible.
Hydrophobic sealants keep water from penetrating through the wall. A protective sheeting can be installed as a barrier between the soil and ground-level building materials. During construction and remodeling, building materials should be kept dry and the amount of water used in mortar and grout must be properly monitored.
Professional Efflorescence Removal
Building managers should turn to a professional facade restoration service to ensure that efflorescence is removed correctly without permanent damage. Removal techniques will depend on the surface material and composition of salt deposits.
Krick points out that technicians will use the gentlest process available to remove mineral deposits. The milder option would be a detergent and rinse, while an alkaline cleaner and pressure washing would be a stronger alternative. In some cases, repainting or remortaring joints can help to seal cracks where moisture can escape. Technicians can then apply surface treatments that prevent moisture from coming through to the surface.
Efflorescence should be addressed as quickly as possible, as mineral deposits can damage the facade to the point where it is permanently scarred. To prevent future damage, managers must also determine and repair underlying issues that may be allowing efflorescence to form.
At Mid America Specialty Services, our facade experts know how to safely remove efflorescence and restore the beauty and value of your building. Contact us today to learn more.