Mold & Mildew fungus growth and the stains that result are considered an "Act Of God" because fungus can only occur in environments where conditions permit. Most composite manufacturers clearly disclose in their product literature that "mold & mildew" and/or "fungus" can be an issue. Even the newer generations of composites, "mold & mildew" and/or "fungus" are only claimed to be "resistant" and still occurs as biofilm on these products, requiring proper cleaning. Unfortunately most composite owners do not read composite literature before purchasing and installing an expensive composite deck, dock or fence.

BEFORE - New Oily Mold Stains On ChoiceDek®

Common mold stains generally start out as black, oily looking, spots on composites when it appears. The photo to the left is what mold stains look like after mold spores (seeds) land on a composite, receive moisture and grow, rooting into the composite. If properly proactively Corte-Cleaned, when first noticed it generally takes a lot less time & Corte*Clean® (expense/money) to clean. If the spores are removed from the composite, prior to the composite receiving moisture, stains will not occur. A leaf blower is all that is generally necessary.

AFTER - Corte-Cleaned ChoiceDek®

The longer the composite owner procrastinates to properly Corte*Clean® black mold stained composites, the deeper the mold roots (hyphae that grow in a mycelium) can grow into porous composites when it receives moisture. Mold stained composites generally require two (2) "repeat" applications of Corte*Clean® at "maximum strength" to thoroughly clean, when first noticed. Be sure to allow the composite to "thoroughly dry" before applying Corte*Clean® & repeating  the application process!

It generally takes two (2) "REPEAT" applications of Corte*Clean® at "MAXIMUM STRENGTH", applied to a "THOROUGHLY DRY" composite to clean mold stains or other difficult to remove stains when first noticed.

Thoroughly Dry Mold Stained Trex®

To the right is a before photo of what mold stains look like when composites have been allowed to "thoroughly dry." Notice how the mold stains DO NOT appear black & oily.  When fungus is allowed to "thoroughly dry", it cannot generally live. When starved of moisture it naturally dies. The fungus roots/stains then become easier to clean from the composite as they shrink while they decompose.

  Corte-Cleaned Trex® Deck

Composite owners will not be purchasing and using as much Corte*Clean® if mold stains are cleaned when first noticed and allowed to "thoroughly dry" in "direct sunlight." The Trex® deck pictured to the right took one application of Corte*Clean® at less than "maximum strength" to remove the mold stains, requiring less time & money to properly clean.

Corte*Clean® works best in removing mold stains or other fungus stains when first noticed and the composite has been allowed to "thoroughly dry."

Oily Mold Stained Composite Not Thoroughly Dry

The picture to the left is of a heavily mold stained composite that is not "thoroughly dry." One can tell it is still wet because the mold stains appear oily. Failure to let the composite "thoroughly dry"  before using Corte*Clean® is not recommended. Always allow composites to "thoroughly dry" before applying or re-applying Corte*Clean®.

Corte*Clean® "works best in direct sunlight between 65-85 degrees F. when composite is completely dry." If one does not allow a composite to "thoroughly dry" before applying Corte*Clean®, the composite owner will likely not be satisfied with the results of Corte*Clean®. Following directions is extremely important when using Corte*Clean®, especially when cleaning black mold stains or other fungus stains.

Using a pump sprayer, spray Corte*Clean® onto the composite and allow it to work on fungus stained composites until it becomes dirty, discolored, heavily saturated. Scrub with a deck brush, if necessary. Brushing will only remove surface dirt and debris and not fungus roots/stains that have grown into composites. "Repeat" Corte*Clean® applications will remove deeply rooted fungus stains. Keep in mind, the longer one neglects to properly clean a composite of mold stains, the deeper the roots grow into composites, the more time & money one can plan on spending properly cleaning a composite to thoroughly remove the roots/stains.

Failure to thoroughly remove mold stains or other fungus stains is a waste of time & money. It will likely result in the fungus returning in a short amount of time. You will only have yourself to blame if you only partially Corte*Clean® composites!

Trex® deck partially Corte*Cleaned® DRY.

Trex® deck partially Corte*Cleaned® WET, with water & need another repeat application at maximum strength on the side that appears clean but isn't. Look carefully, the mold stains still appear.

The following photo, below, is what an extremely neglected composite looks like after mold and green lichen or moss (commonly confused with algae) has been allowed to exacerbate itself with the help of dead organic material (food) and moisture. Unfortunately the owner of the before pictured composite has made the unsightly problem worse by neglecting to properly clean it for years. The below Correct Deck® took several additional "repeat" applications of Corte*Clean® at "maximum strength" to get thoroughly clean. Additionally, this deck required heavy brushing and more abrasion.

If more abrasion is needed, when brushing, to remove surface debris and build up, as was the case when cleaning this composite, sprinkle Corte*Clean® powder directly onto the composite already wet with Corte*Clean® at "maximum strength." Then scrub with a brush until the Corte*Clean® becomes dirty/discolored/heavily saturated with whatever it is cleaning from the composite. Rinse with water and "repeat" the Corte*Clean® application process until thoroughly clean.

Always allow composites to "thoroughly dry" in between applications of Corte*Clean®. Failure not to allow the composite to "thoroughly dry" in between applications will generally result in Corte*Clean® failing to thoroughly clean the composite!!! A sponge mop or rag will speed up the dry out time, in between applications.

If the composite you intend to Corte*Clean® has been neglected or unproven cleaning products have been previously used, that are scientifically proven to exacerbate mold growth (see scientific study on "Advantages" page), it may take several additional "repeat" applications of Corte*Clean® to thoroughly clean.

Failure to thoroughly clean composites and items on, attached to or above composites of black mold stains or other fungus stains is a waste of time. Examples of these items are furniture, flower pots, umbrellas, siding, roofing, concrete, bricks, etc. If the stains aren't thoroughly removed from these items or composites, it is likely that spores still remain. If this is the case, the contamination process will likely immediately return, when spores land on the composite and receive moisture, wasting time & money. If you do not plan to thoroughly Corte*Clean® composites and surrounding items, the owner of these items is wasting time & money.

Extremely Neglected Mold Stained Correct Deck®

One can tell when a composite is thoroughly Corte*Cleaned when you can no longer see stains anywhere!!!!

"Repeat" application needed!!!

If you can still see fungus stains, as on the above composite, and the composite is not thoroughly Corte*Cleaned, they will generally, almost immediately return, when the composite is exposed to moisture. Spores likely still remain! The above composite photo needs another application of Corte*Clean® to thoroughly remove the noticeable staining. Make sure a composite is thoroughly Corte*Cleaned; otherwise you are wasting time & money.

The above dry TREX® deck looks fairly clean. Don't be fooled!!! Mold stains still remain in all boards except the lower half of the center board (in between the two white shoes) which was Corte*Cleaned.

The above photo shows how water magnifies mold stains on/in composites. If the composite is wet, with water, and mold stains are still noticeable, one must "repeat" the Corte*Clean® application process at "maximum strength." Make sure the composite has been allowed to "thoroughly dry" in-between applications!!!!! One can see, in this picture where Corte*Clean® has and has not been used, except on the one center board, around the nail in the lower half of the photo.

Save yourself time & money! Proactively Corte*Clean® composites that are located in areas where spores exist. This is what the reduced strength on the Corte*Clean® label directions is for. Keeping a composite clean can be as simple as spraying Corte*Clean® on a "thoroughly dry", somewhat clean composite before it receives moisture. This is the least expensive, safest & fastest way to keep a composite clean.

Click Here for Mold Spores

&

Click Here for the Weather Forecast

The less thoroughly one rinses Corte*Clean® upon the final application, when it is no longer becoming dirty, discolored and/or heavily saturated, the longer it will continue to clean any time it receives moisture. One can apply a final application of Corte*Clean® to a thoroughly Corte*Cleaned composite and allow it to dry on the composite prior to the composite receiving moisture. This will result in the Corte*Clean® soaking into porous composites. An ugly white residue will likely remain until thoroughly rinsed. Always thoroughly rinse the composite before allowing people, children, pets or other animals on the composite. The best way to do this is to allow the natural moisture from rain, morning, snow, ice or high humidity rinse the Corte*Clean®.

TREX® with Corte*Clean® residue still remaining.

Mildew stains are a white & sometimes gray silky coating that are common on wood or other dead organic materials and not common on synthetic plastic composites. Mildew is a specific species of mold in the fungus family. Mildew stains are generally caused by dead organic items like fire wood or leaves that have been allowed to sit on composites and decompose. 

The picture below is an example of where a wood flower box sat neglected for years on this TREX® deck, resulting in white colored mildew stains, heavy common black mold stains & green lichen or moss stains. Not to worry, Corte*Clean® will easily clean all common fungus stains although 5 repeat applications were required to clean the below deck at "maximum strength."

Dirty Trex® never cleaned since the early 90's!!!

If a composite looks like the one above, and has been neglected for years, or a "mildew stain" remover has been previously used, that contains "sodium hypochlorite" it will likely cost more time & money to Corte*Clean®. Make sure you purchase enough Corte*Clean® to do the job! This is because you will likely need to "repeat" the application several additional times beyond the normal two (2) "repeat" applications at "maximum strength" to thoroughly clean composites that look like this.

If the composite deck you intend to Corte*Clean® looks like the one above, and is 300 square feet, you will need double to triple+ (2X to 3X+) the amount of Corte*Clean® generally needed to clean 300 sq. ft. Instead of one (1) bag, you will likely need two to three+ (2 to 3+) bags to do three or four (3-4+) "repeat" applications. You are paying for whoever neglected the composite. Cleaning this composite deck will likely cost you additional time to do the job. Make sure you only work small sections of no more than 10 square feet at a time until you get the hang of it or feel comfortable cleaning additional area.

Make sure you get the composite as clean a possible with a brush and water before using Corte*Clean®! Make sure the composite is then allowed to "thoroughly dry" before using Corte*Clean®. Mix the Corte*Clean® at the “maximum strength” on its label directions. Spray the mixed Corte*Clean® on to the composite surface, then sprinkle some Corte-Clean® powder onto the area already wet with Corte*Clean® and brush with a deck brush. This will make Corte*Clean® more abrasive and help remove debris stuck to the surface of the composite. Once the heavy surface build up is removed from the surface of the composite, you will no longer need to sprinkle Corte*Clean® powder onto the area already wet with Corte*Clean®. Rinse with water and "repeat" Corte*Clean® application process at "maximum strength" until composite is thoroughly clean.

when cleaning composites that are not kept clean from the time they are new, is that the mold stains and other stains can block the sun from evenly bleaching, fading or naturally weathering composites. This exact same issue occurs when items such as flower pots, furniture, door mats,  etc. are placed on new composites and never moved, after the composite is installed.

The Corte Cleaned above Fiberon® deck had a fireproof barbecue mat on it that  blocked the sun from evenly weathering the composites.

Another example of a weathered TimberTech® deck that has been thoroughly Corte Cleaned. See the square un-weathered area where furniture blocked the sun from evenly weathering this composite? Notice the area of this photo, on the left, that is wet with water.

The above Veranda® Corte Cleaned composite has a natural weathering issue, just like the TREX®, TimberTech®, Fiberon®/Veranda® decks above. The Veranda® deck shows where mold stains have been allowed to block the sun from evenly naturally weathering the composite. This is an extremely common issue on composites that are not kept clean.

One can tell that this is a weathering issue when the composite is dry. Weathering issues generally don't show up, as noticeable, on wet composites. If black colored spots are still noticeable when the composite is wet, with water, mold stains are likely still present and another "repeat" application of Corte-Clean® is necessary to remove them.

No cleaner will resolve weathering issues without bleaching the composite beyond what the sun will naturally. Not to worry, exposure to the sun will naturally weather this issue away. How long? Generally 8 to 10 weeks of direct sunlight or as long as the area was protected from direct sun exposure.

Corte Clean® will expose "Natural Weathering", that TREX®, and other manufacturers, disclose in their literature and on their websites. This  "Natural Weathering" occurs around where "mold" stains where, but not under the "mold" stains, as demonstrated in the photos above. Corte Clean® will not bleach out the color of TREX® beyond what they disclose as "Natural Weathering", like when using sodium hypochlorite (Chlorine Bleach) based biocides, as TREX® points out in their "Bulletin." This is what many Corte LLC tests, with Corte Clean®, have also proven. Do your own test, and you will see, that this is true, not only with TREX®, but most composites.

Please contact us if you have any questions before or after using Corte-Clean®. We don't want you to waste your time or money!!!! We want to make sure we help every customer.

The following information is what Corte LLC, and more importantly our customers, have proven to keep composites clean & free of MOLD & MILDEW stains.  

1. Proactively sweep or use a leaf blower to remove microscopic mold spores and other debris that it can feed on from a composite before they receive the moisture they need to live, grow, root into the composite and cause ugly mold stains.
   1. A good electric leaf blower can generally be purchased for under $40 at hardware stores.
2. After using a leaf blower, sprinkle Corte-Clean® powder onto a thoroughly previously Corte Cleaned composite surface, before it receives moisture from rain, morning dew, etc.
   1. This technique removes any microscopic mold spores trapped in the pours or other tight places when the composite receives moisture.
      1. This technique works best in a light rain or morning dew.
      2. The composite should not be used until the Corte-Clean® is thoroughly rinsed from the composite.
      3. The advantage of this technique is that it takes minimal time, effort, and Corte-Clean®.
         1. The disadvantage of this technique is that it does not work in medium to heavy rain.
            1. This technique should not be done in medium to heavy rain because it will rinse the Corte-Clean® powder from the composite before it has a chance to do its job, wasting time & Corte-Clean®. 
               
               1. The following technique works best in medium to heavy rain.
3. This technique works the best and is the most reliable but takes more time and effort. After blowing a composite with a leaf blower, the composite owner can mix up the Corte-Clean® at the diluted strength on its label, spray it on the composite, and rinse it with water after letting it work for 15-20 minutes.
   1. This will remove any items from the composite before they have the chance to cause deep, difficult to remove stains.
      1. If the Corte-Clean® is not becoming dirty or discolored, the Corte-Clean® can be allowed to dry on the composite. This will leave the white Corte-Clean® residue behind while allowing it to soak into the composite.
         1. The Corte-Clean® will continue to clean the composite any time it receives moisture until thoroughly rinsed.
         2. It is a great idea to do this technique before it rains, before a vacation or if the composite will not be used for any amount of time such as the winter months.
         3. The owner of the composite should thoroughly rinse the Corte-Clean® before allowing children, animals or people to use it.
4. Make sure all items surrounding or attached to the composite are clean and free of mold stains.
   1. EXAMPLES: Roofing, siding, windows, concrete, funiture, flower pots or planters, BBQ's, sun shades, etc.
      1. Failure to clean these items can and generally will result in fungus spores coming from them, re-contaminating the composite, wasting time and money.
         1. Keeping mold staining from returning to composites is kind of like pulling weeds. If you don't pull all the weeds from the yard, while getting the roots and seed pods, the weeds/mold stains will likely return. This is the biology of this incredibly resilient organism.

For additional information on what Corte LLC and more importantly our customers have proven effective in keeping a composite clean, please carefully read the Corte-Clean® "FAQ'S!" After all, nobody wants to spend time or money cleaning a composite. Hopefully this info helps so the composite owner(s) spend more time enjoying composites and less time & money cleaning them.

 CLICK HERE to continue on to the Corte-Clean® "Advantages" page.