Why Chlorine Bleach or other sodium hypochlorite based products is Not Smart for Cleaning Composites!
Corte LLC freely admits that sodium hypochlorite based products generally appear to quickly bleach out mold, on most composites, the first several times used. Don’t be fooled! The following photo is an example of what a composite deck looks like when sodium hypochlorite, the active ingredient in chlorine bleach, and common deck cleaners generally designed to clean “wood” of “mildew”, which is not common on composites, has been repeatedly used. Notice how the sodium hypochlorite no longer bleaches out the mold stains. Notice how the composites are turning solid black, and no longer spotting, becoming deeply rooted and infested in the composite, while it feeds off of the tannin from exposed wood fibers. The sodium hypochlorite sterilizes the composite of everything except the mold, making it a perfect environment for mold spores to grow when they receive moisture. Perhaps this explains why so many composite manufacturers that have routinely recommended chlorine bleach or other sodium hypochlorite based cleaners for cleaning common black mold, have ended up with so many unhappy customers. The left side of the below photo shows how water magnifies mold stains, which have been exacerbated by the routine use of products containing sodium hypochlorite. The below photo shows how Corte*Clean® will clean these stains when sodium hypochlorite no longer bleaches out the mold stains. This photo represents a classic example of why sodium hypochlorite should never be recommended or used to clean composites of mold stains.
Sodium Hypochlorite is Scientifically proven to exacerbate mold issues, with wood, from which most composites are 50% made, by a scientific study conducted by Oregon State University, titled “Ability of bleach and other biocide treatments to remove and prevent mold growth…”. This scientific study explains why those that ignore science, and recommend or use sodium hypochlorite to clean mold, experience the Rapid Return of MOLD! This is the #1 complaint in the composite decking industry.
Why sodium hypochlorite isn’t smart for mold cleaning.
- Kills plants grass surrounding composites.
- Off-Gasses chlorine smell when used and after being used.
- Causes Corrosion to Structural Metal Fasteners & Connectors, the #2 biggest issue in the decking industry, which leads to rust stains around metal fasteners, such as screws or nails which is expensive to remove with another cleaning product, which is not compatible with sodium hypochlorite.
- Need to purchase and use other expensive products for specific stains such as grease, oil, rust, tannin stains, etc. which are not compatible with sodium hypochlorite.
- Doesn’t eliminate “tannin bleeding” which can feed funguses such as mold.
- Scientifically proven to exacerbate mold issues, resulting in its rapid return, leading to the #1 complaint in the composite decking industry.
Composite cleaned with chlorine bleach.
Here is a testimonial/review of a sodium hypochlorite based product that proves the point by a composite deck owner, however, this deck likely doesn’t have “mildew” but rather common black mold stains.
JimC – Review provided by Lowes (through Google Shopping)
I have Trex decking. I have to clean it once or twice a year to get rid of mildew spots, which are getting worse and worse and harder to deal with. The folks at Trex recommended the [sodium hypochlorite] product. It made the spots better, but certainly didn’t get rid of them. I still have a “leopard pattern” deck.
Perhaps it is because this product was originally designed and labled to clean “wood” of “mildew”, not plastic/wood composites of common black mold stains?