Corte LLC freely admits that sodium hypochlorite based products appear to quickly bleach out mold stains on composites when first used. Don't be fooled! The following photo is an example of what a composite deck (TREX®) looks like when sodium hypochlorite, the active ingredient in chlorine bleach and unscrupulous deck cleaners generally intended for only cleaning "mildew" (not the species of mold 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, exacerbating the problem, making it take more time and cost more money to Corte-Clean® in the future. If this composite were wet, it would look much worse because water magnifies stains on composites.

The second photo (below) left side shows how water magnifies mold stains after the mold staining problem has been exacerbated by the use of products containing sodium hypochlorite on this ChoiceDek®. Notice how the mold spots have grown into one massive mycelium of hyphae. The right side of this photo shows how Corte-Clean® will clean these stains when sodium hypochlorite no longer bleaches out the mold stains and the problem has been exacerbated.

These photos represent a classic example of why sodium hypochlorite should never be recommended or used to clean composites of mold. Additionally, the use of sodium hypochlorite to clean composites leads to many other safety and environmental issues. If you are still not convinced why sodium hypochlorite containing or mixed with products should not be used, keep on reading.
- Toxic, Dangerous, Polluting & Unhealthy!
- Generally Kills plants grass surrounding composites.
- Pollutes Streams, Rivers, Lakes, Estuaries, or the Ocean and is not generally legal to let drain into these natural waterways.
- Where do you think it all goes?
- Read any reputable brand of chlorine bleach label directions to confirm.
- Fines can be quite expensive or worse if caught by the authorities.
- Off-Gasses unhealthy chlorine when used and after being used.
- Unhealthy to breath, especially for the young, the elderly or those with Asthma, Bronchitis, Emphysema or other respiratory conditions.
- Chlorine Is A Key Component Of Dioxin. Click Here For More INFO.
-
Extremely dangerous when accidentally or intentionally mixed with other cleaners such as; products that are dangerously/illegally mixed with chlorine bleach that contain; ammonia, ammonium, oxalic acid or when coming into contact with the chemicals commonly used to
Treat Lumber that structurally support most composite decks, docks & fences.
-
Breaks down wood
Lignin (Natural glue) that gives wood its strength including structural lumber that support most composites.
- Causes Corrosion to Structural Metal Fasteners & Connectors (steel, galvanized & stainless) holding most composites together.
- Leads to ugly stains that need to be cleaned with another expensive, time consuming and generally polluting chemical or expensive early replacement or failure.

The above photo is of Sodium Hypochlorite Corrosion Stains to visible fasteners, What do you think it does to the structural connectors that are not generally visible? WARNING!!! DANGER!!!
- Simpson Strong®-Tie Manufacturers Approximately 77% Of All Decking Hardware, Including Swan® Secure Fasteners, Clearly Disclose The General Corrosion Risks Of Cleaning chemicals Like Chlorine Bleach, Products Dangerously Mixed With Chlorine Bleach Or Cleaners Containing Sodium/Calcium Hypochlorite.
- USP® Structural Connectors manufactures much of the remaining metal decking hardware and clearly discloses Causes Of Corrosion From External Attack By Chemicals Like Chlorine Bleach, products dangerously mixed With chlorine bleach or cleaners containing sodium/calcium hypochlorite.
- Why would any person or company manufacture, recommend or retail corrosive cleaning chemicals for cleaning decking when the chemical will likely come into contact with structural metal components, especially since the risks are so clearly disclosed?
- Not Recommended By The United States Environmental Protection Agency (EPA) To Clean Mold.
- Not Recommended By The United States Occupational Safety Health Administration (O.S.H.A.) To Clean Mold.
- It is a violation of Federal (EPA) law to use a biocide in any manor inconsistent with label directions.
- The History Channel Modern Marvels Episode "Mold & Fungus"
- Premiere Date: 09/18/2008
- "DO NOT USE BLEACH TO CLEAN MOLD"
- Approx 10 to 15 minutes from beginning of episode.
- Oregon State University Scientific Study Ability of bleach and other biocide treatments to remove and prevent mold growth
- Sapwood lumber is commonly used, in part, to make most composites.
- Corte LLC has experienced these same results when using chlorine bleach and other biocide treatments to remove and prevent mold growth from composites.
- Why would any person or company manufacture or recommend biocides such as chlorine bleach or other sodium hypochlorite based deck cleaners for cleaning mold when this chemical is scientifically proven to exacerbate mold growth on lumber commonly used to make composites?
- Town Country Magazine SPECIAL GREEN ISSUE 4/2007 p.180 -Cited this source.
- Chlorine bleach will evaporate within a short period of time, especially when it is used in hot temperatures and the composite surface is in direct sunlight. If the composite is not dry when the bleach evaporates, or moisture is still in the contaminated area on the composite (humidity, outside air dampness, etc.), the contamination process is re-started immediately and to a greater degree.
- American Chemistry Council Chlorine Division (ACC)
- You will find many legitimate uses for chlorine, the active ingredient in sodium hypochlorite, on the ACC website which is funded by the major producers. You will not find any information from the ACC for cleaning, killing or removing mold or mildew from any surface including composites. Why do you think this is?
- Chlorine Online Information Resource
- You won't find any information related to using chlorine to clean mold or mildew from the Chlorine Online Information Resource but you will find many other legitimate uses. They too are funded by the chlorine industry.
- Not effective on Porous composite surfaces for cleaning mold.
- For proof, read the label on chlorine bleach containers.
- Not effective for cleaning Grease, Oil, Rust (Causes Rust) other common staining issues from composites.
- Chlorine bleach and other sodium hypochlorite containing biocides generally loose most of their TOXIC strength through off-gassing of chlorine within the first three (3) to six (6) months after being manufactured, even in a new, unopened container.
- One of our competitors, that contain sodium hypochlorite, clearly discloses their products Thirty-Five (35) Day shelf life.
Unfortunately, some continue to manufacture, recommend and sell toxic, corrosive, polluting and dangerous chlorine bleach or other sodium hypochlorite containing/mixed biocides cleaners to clean mold. Most recommend this chemical because of beliefs and not science or because they have been sold a product that initially appear to quickly remove the mold stains when first used. Nothing could be further from the truth. Use of sodium hypochlorite makes mold problems worse. Its use does not kill or remove mold (dead mold can still be toxic) but is scientifically proven to help it grow. It does this by bleaching the mold out (so you think you have removed it).
In reality, its use makes the mold more resistant to the chlorine in sodium hypochlorite. Because most sodium hypochlorite containing products are generally 92-97% water, they actually give the microscopic mold spores and mold hyphae the moisture they need to live and grow, resulting in immediate re-growth. This allows the mold to grow throughout the composite in one massive mycelium, making the problem far worse and more difficult to clean in the future.
Repeat use of sodium hypochlorite will do damage to the structure supporting the composite, the environment and the health of anything living, except the mold. Cleaning recommendations of sodium hypochlorite containing/mixed with products are the #1 issue facing the entire composite industry. Poor cleaning recommendations are giving these great, generally environmentally responsible, longer lasting, alternative products a less than desirable reputation. This has lead to health/pollution/safety issues, federal law violations and the further depletion of our planets forests.
Hopefully, through our efforts, we will continue to educate composite owners, manufacturers, distributors and retailers, while getting every customer's composite clean, in an environmentally responsible manor, without all the known risks of sodium hypochlorite and teaching them how to keep it that way at a minimal cost with minimal effort, especially when it comes to mold stains.

Photo of composite deck previously cleaned with chlorine bleach by an employee. The composite is still wet. See the black mold?

Same composite deck approx. 2 weeks later. Composite is dry. See the mold?

Same composite deck (as above photo). Composite is wet with water. Water magnifies stains on composites. Will you be another victim of what is commonly known in the scientific community as; The Chlorine Bleach Scam?

Same composite deck/spot after being Corte Cleaned! Composite is wet with water.