Preventing and Removing Mold

Any composite exterior material is vulnerable to mold. Here are some important facts your customers should know about Trex and mold:

• Like any exterior building material, Trex requires periodic cleaning and maintenance to help prevent mold.
• Mold does not damage Trex and will cause no harm if allowed to propagate.
• Mold can be removed from Trex using a variety of commercial cleaning substances.
• Mold spreads easily and may return in some environments despite proper cleaning and preventative measures.

Below you will find information about what causes mold, how to prevent it and how to remove mold from Trex products. For more information about mold, you can also refer to our mold bulletin.

Understanding What Causes Mold and How to Prevent It

Mold is a form of plant life that can settle and grow on any surface. Mold spores are similar to seeds, but cannot be seen until colonies form. These spores can be transported easily through air currents, insects, animals and water.

In order to form visible colonies, mold needs food, moisture and temperatures between 40 and 90° F. Trex itself is not a food source for mold, but can collect food in the form of dirt and debris—such as the overflow from flowerpots and gutters. Periodic cleaning of Trex decking will remove dirt and pollen that can feed mold. Excess moisture that causes mold can also result when the gaps between Trex deck boards are too small or clogged. You can find more about gapping instructions on the usage guidelines page.

How to Remove Mold from Trex

Mold can be removed from Trex using a mixture of detergent and bleach, as is found in a number of commercial deck cleaners. Make sure your customers are aware that while bleach will remove the mold, it will also lighten the wood on the surface. In some cases several treatments will be necessary to completely remove all mold colonies. And even if the spots are no longer visible, there may still be mold spores on the surface that could re-grow, so periodic cleaning is important.

The following brands of deck cleaners have been found to be effective in removing mold from Trex decking:

• Olympic Deck Wash*
• Expert Chemical™** Composite Deck Cleaner & Enhancer (www.expertchemicalinc.com)

Always apply these products to a dry deck. Applying to a wet deck will significantly reduce the effectiveness of the cleaner. NEVER mix any other cleaners (ammonia, phosphoric acid, etc.) with bleach.

Should you prefer an eco-friendly (no bleach) product, the following will reduce the appearance of mold on the decking surface:

• Corte-Clean®*** Composite Deck Cleaner (www.corteclean.com)