Efflorescence is a problem inherent in concrete, masonry, and stone products. As GFRC shares the same Portland cement base that precast concrete does, it can experience the issue as well. Efflorescence is caused by the moisture that disintegrates the mineral salts found in some concrete. When the moisture evaporates, it leaves behind the salts which cause a dusty white residue that discolors whatever surface they collect on.
With GFRC, this is largely an aesthetic issue as GFRC is a non corrosive material and will not rapidly decline when in contact with salts as precast concrete and some masonry will. But it is still worth knowing how to prevent and clean efflorescence if your building has GFRC installed.
Mitigating Efflorescence on GFRC Architectural Elements
GFRC efflorescence has two separate types. Primary efflorescence is a result of the manufacturing process and the remaining moisture and salts in the curing concrete or masonry coming to the surface. Secondary efflorescence occurs from environmental moisture after the installation of an architectural element and throughout its lifetime if the salts are present in the concrete.
Preventing primary efflorescence necessitates having the right cement mixture and an experienced team during the manufacturing process. This will cut down on the risk of efflorescence after curing. For existing buildings with GFRC installed that are experiencing issues will efflorescence, you can take the following actions to reduce the problem:
- Fix Moisture Issues – Reducing contact with moisture is one of the most effective ways to limit GFRC efflorescence problems. This can be somewhat difficult when architectural elements are outside and exposed to the elements, but incorporating the correct gutters and downspout solutions, directing irrigation away from building facades, and eliminating standard water with proper drainage can help reduce issues.
- Sealing GFRC Surfaces – There are sealants available that will reduce the porosity of a GFRC surface. This helps to keep water out so that it will not come into contact with any salts within the GFRC and dissolve them.
- Clean Stained Surfaces – Because efflorescence results only in salts that stay on the surface, they can be readily washed away with water and the white staining removed. Using a hose to wash surfaces may be enough in many cases and soft power washing can free more ingrained salts.
At GC Products, we make GFRC architectural elements that are built to last and also retain a high quality, professional appearance throughout the lifetime of your building. Our exterior GFRC products resist corrosion, staining, and other damage for a highly durable product at a great cost. Contact us to discuss your project, get a quote, and get more information on GFRC.