Mold & Mildew Stained Composites
Mold & Mildew or other fungus growth, such as common green lichen or moss (often confused with algae), and the stains that result are considered an “Act Of Nature” because fungi can only occur in environments where spores exist, they land on a surface and receive moisture, such as in the outdoors, where composites generally are located. This is generally true unless composites are made of recycled wood fibers and/or recycled plastic where molds were manufactured into the composites. Due to this fact, composite manufacturers generally clearly disclose that “mold & mildew” and/or “fungus” can be an issue in their product literature.
Picture of a neglected PVC “CAPPED” composite deck growing a green & black mold “biofilm”.
The second generation of composites, which are generally made from PVC exterior “CAP”, with a recycled wood & plastic core, state “mold & mildew” and/or “fungus” are only claimed to be “resistant”. Manufacturers generally disclose that fungi can occur as “biofilm” on these products exterior. Unfortunately, most of these yet unproven composites haven’t stood the test of time & some owners are already starting to have issues.
Newer 2nd generation PVC “CAPPED” composite with recycled wood & plastic core. Is that black mold growing under the “CAP”? If so, we don’t believe any cleaner, including Corte Clean®, can get under the PVC “CAP” to clean the mold stains growing in the wood & plastic core. Is moisture getting in from the end cuts & screw holes, watering the fungi allowing it to grow? Will this lead to de-lamination, especially in freeze thaw environments?
Unfortunately most composite owners do not read composite literature before purchasing and installing an expensive composites, which generally state to clean at LEAST twice yearly (2X), Spring & Fall, or when stains appear, so they are unaware. Rather, composite owners choose to believe claims that composites are absolutely “NO MAINTENANCE” and will never need to be cleaned often propelled by the uneducated at retailers or installers. Unfortunately these composite owners don’t find out that most composites get dirty, with all kinds of common stains, including those from common black mold stains and other common stains until they shows up. They often have no idea what it is?
Picture of a ChoiceDek® Plus® with black mold stains rooting into the recycled PE plastic & Oak wood fibers from which it was made.
Common mold stains generally start out as black, oily looking, spots on composites when it appears. The below photo is what mold stains look like after mold spores (seeds) land on composites, receive moisture, grow and root into composites. If properly proactively Corte*Cleaned®, before the composites receive moisture, hatch, and root into the composites, it generally takes a lot less labor/time and Corte*Clean® (expense/money) to maintain a composites clean appearance.