Efflorescence is a common phenomenon seen on the exterior of buildings, evidenced by discoloration or white streaks. It is frequently misperceived as a product malfunction, when in reality, it is an application failure. So, what is this issue and how does it affect exterior insulated finishing systems (EIFS)?
What is efflorescence?
The term efflorescence comes from the Latin word for “flower”, symbolizing the act of blossoming or blooming like a flower. In this case, the blooming refers to microscopic particles found in cement that react with moisture and develop mineral crystals.
As these crystals loosen and the water evaporates, the free crystals, made mostly of salt, are deposited on the surface of the substrate.
In masonry, visible white streaks can appear on the face of the brick, CMU block or stone. Efflorescence can also make newly poured concrete look white whereas the same concrete poured inside of a building has the intended rich gray color.
Beyond aesthetics, an added challenge with efflorescence is that it makes for a surface that is nearly impossible to adhere to. In EIFS, any efflorescence on the cementitious base coat prevents the finish coat from bonding properly, which can lead to unsightly peeling. This detachment can occur within days of the application.
Whose Responsibility is It?
When efflorescence is evident, the building owner or property manager should first go to the coating applicator. Efflorescence is typically a problem with the installation process, so it is the applicator’s responsibility to address any issues related to it.
How to prevent efflorescence:
It is important to note that efflorescence CAN be prevented. Substrate preparation is a must in any coating application and applicators must be careful not to introduce any excess moisture. For EIFS installations, make sure that the base coat is covered and protected from the elements prior to the finish coat being applied. The same precautions should be taken for insulated brick veneers where added moisture from the mortar itself or precipitation during the curing process can be problematic. Conversely, make sure that the building envelope is watertight before installing a new EIFS façade, as water infiltration behind the coating can cause the same salt deposits.
How to fix efflorescence:
To remediate existing problems associated with efflorescence in EIFS, here are a few options:
- Clean and recoat
In most cases, the efflorescence can be cleaned off with a mild solution, left to dry, and then a new base and top coat can be applied.
If your base coat will be exposed for a long period of time, consider applying a colorpriming material over your base coat to offer added protection until the top coat can be installed.
If the efflorescence is widespread, it may be necessary to replace the entire EIFS facade and start again. A benefit of panelized systems and insulated brick veneers is that any issues can be easily repaired. Simply remove the affected panels or bricks, ensure there is no added moisture or leaks behind the system, and swap in the new pieces.
While efflorescence is a big concern for many building owners, it is usually a low-cost fix. For contractors and applicators, you can avoid it altogether by paying attention to current moisture in the building envelope and anticipated weather conditions. These precautions protect the building envelope and ensure a beautiful, durable EIFs façade for years to come.