Composite decking is made from a combination of natural wood fiber and resins. It resembles real wood but doesn't rot, warp or crack. Composite decking is also available in a wide range of colors, which eliminates the need to paint or stain it. Although you can place welcome rugs or barbeque grill mats over composite decking, some types of backing materials are not recommended and periodic care and maintenance is required to prevent staining or discoloration.

Welcome mat
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Rugs and mats may damage or stain composite decking.

Types of Mats and Rugs

Composite decking is resistant to most stains. However, some mats and rugs have backing materials that should not be placed on composite decking. Mats that are backed with rubber or latex can leave marks on the decking. These marks are often removable, but it is best to avoid them entirely by using vinyl-backed or colorfast woven rugs only. Avoid using mats or rugs that have metal grommets or accents, which can rust and stain the composite decking beneath. If rust stains do occur, clean the deck with deck cleaner that contains phosphoric acid and a commercial pressure washer. Check with the manufacturer to determine the maximum pressure to use. If you use too much pressure, the color can be stripped from the decking boards.

Weathering

During the first few weeks after installation, composite decking may naturally show color variation as it weathers. This typically results in a color that is slightly lighter than the original color. Most composite decking changes color due to weathering during the first three to six months after installation and if allowed to weather evenly, the change is not usually noticeable. Placing mats or rugs on your decking during this time can result in inconsistent color variation due to uneven exposure to the elements, so it's best to avoid placing mats on your composite decking for at least three months to prevent uneven coloration. Composite decking also requires adequate airflow between the boards. To ensure this is provided, avoid covering your deck entirely with rugs or carpeting.

Water Stains

With some types of composite decking, water stains can occur if moisture is trapped beneath rugs or mats for a prolonged period. Kodiak recommends spraying your composite decking with a hose immediately after installation to hydrate the material and to prevent this discoloration. If you notice later that moisture beneath a rug or mat has caused water stains, remove the rug and rinse the deck with a hose. Make sure to cover each board evenly and then let the deck dry naturally. The water stains should fade after a few days and you can replace the mats when the deck is completely dry.

Dirt, Grim, Mold and Mildew

Periodically, all mats and rugs should be lifted and the decking beneath cleaned to remove dirt, grime, mold and mildew stains that can occur beneath. Water and dirt can accumulate beneath any mat and over time and this leads to mold and mildew growth. Dirt and dust are easily cleaned from composite decking using a garden hose and a soft-bristled brush. Most composite decking is made to be mold and mildew resistant, but with prolonged exposure to dirt, organic material (such as leaves) and moisture it is not impossible for mold and mildew to form on the mat and transfer to the surface of the decking. These can be cleaned with water as well, or a deck cleaning formula designed specifically for composite decking.