General Decking FAQ

How can I prevent mold from growing on my deck?

To minimize mold on the decking, clean the deck as often as needed but at least twice each year. Climate conditions vary in different regions of the country and may necessitate more periodic cleaning. In some situations, you may need to repeat the cleaning process multiple times until you are no longer able to see any “shadows” of the spots on your deck while it is wet. You would also want to apply a mold inhibitor to retard future growth. Once the decking has been thoroughly cleaned, you will need to maintain it in much the same way you would adhere to a cleaning schedule for any other significant item in or around your home.

What products do you recommended for removing mold from a deck?

Fiberon recommends the following two products:

• 30 Seconds® Outdoor Cleaner
• 30 Seconds® Spray and Walk Away
When used in combination, these two products provide a “one-two” punch to help control mold and mildew. Both are heavy duty, mildly alkaline, chlorinated mold and mildew removers/cleaners that are biodegradable once rinsed into the soil. Both have been tested and perform very well in removing mold and mildew and retarding its return on our uncapped composite decking. Consumers can find these products on the manufacturer’s website, at most Home Depot® locations, and through They are also available at most Walmart® stores and Ace® Hardware locations.

Can I power-wash my deck if there is mold present?

No. Power-washing will only worsen the mold problem. The pressure of the power washer actually pushes the mold further down into the pores of the material. We DO NOT recommend power washing the decking while mold or mildew is present. If a pressure washer has been used, we recommend at least two applications of cleaner to ensure that the roots of the mold are thoroughly neutralized. A pressure washer can also, if used improperly, damage the deck surface. We recommend exercising extreme caution when using a pressure washer for deck cleaning. Remember to keep the tip at least 12 inches from the deck surface to prevent damage.

What makes one Fiberon deck board different from the others?

We organize our decking lines into Good/Better/Best categories. Every Fiberon deck board offers lasting durability, easy maintenance, and a great warranty. The big differences come down to the aesthetics (the color, streaking, and grain patterns); the cap layer (the protective cover that provides stain and fade resistance, among other things); and the price. Watch this short video which explains the unique properties of each line.

Can I install Fiberon decking with another manufacturer’s hidden deck fasteners?

Only Fiberon Phantom hidden deck fasteners are recommended for use when installing Fiberon decking. (Note: hidden fasteners will only work with grooved edge boards, not square end boards.) Using another manufacturer’s product will void your warranty, and may result in an unsatisfactory installation. Trex Universal Clips, for example, do not hold the boards securely during thermal expansion and contraction caused by temperature swings. Consequently, you could experience significant end-gapping issues.

Always read and follow Fiberon decking installation instructions to ensure correct installation and keep your warranty coverage intact.

What is picture-framing a deck?

“Picture-framing” refers to putting a border around the edge of a deck or porch. On a composite deck or porch, picture frames are constructed using square-edge boards and mitered corners to ensure a clean, finished look.

Among the reasons to consider a picture frame:

  • It heightens visual interest. Most contractors will use one color for the deck’s interior and then a contrasting shade for the picture frame. This enhances the custom look of the space and creates a border that really pops.
  • It creates a polished look. Framing with a square-edge board will cover the exposed ends of interior boards as well as hide the edge on grooved decking that is used with hidden fastening systems.
  • It highlights deck stairs and edges, visually reminding guests to watch their footing. That’s a smart, easy way to enhance safety on your space. One thing to consider: Darker picture frames are easier to see during the day; however, lighter picture frames are often easier to discern in the evening – especially if you don’t have riser lights on stairs.

Picture-framing is also effective for defining specific zones on your deck, such as the dining area, as well as highlighting special features like a fire pit.

One final tip: Be sure that the width of the picture frame is in correct proportion to the size of the overall deck. If you’re working with a large space, you may want to create a wider, two-board-width picture frame. If the deck is smaller, stick to one board width.


Can Fiberon Decking be installed over existing joists and framing?

Yes, Fiberon Decking can be installed over an existing substructure if the following conditions are met:

  1. The existing framework must be free of any damage or decay; i.e., in good, workable condition (consider having the space assessed by a licensed deck inspector)
  2. The joists must be spaced correctly
  3. There must be adequate cross ventilation and unobstructed airflow under 50% of the deck. Allow a minimum of 1.5 inches (4 cm) between bottom of joist and the ground. Water must be able to flow away from under the deck. Improve drainage or grade flat areas where standing water may gather, and do not install decking directly to an existing or solid surface.

Can Fiberon products be used for any part of the decking substructure, frame or joists?

Fiberon composite decking has many outstanding qualities; however, it is simply too flexible for use as a structural component of a deck. When installing Fiberon decking, please follow all installation guidelines and local building codes.

How do I replace a deck board?

Deck Board Replacement:

1. Make two parallel cuts down the center of the board to be replaced. Remove the center section from the board (fig.1).

2. Remove the remaining two pieces from the tabs of the corresponding hidden fasteners.

3. With a reciprocating saw, remove the tabs on the fasteners which have the screw showing (fig. 1a).

4. Position the new deck board onto the remaining tabs (fig. 2).

5. Ensuring a consistent 3/16” gap between boards, predrill a 1/8” hole along the unfastened edge at every support joist.

6. Secure the board by fastening a #10 x 2-1/4” long stainless steel deck screw in each pre-drilled hole.

What are fascia and riser boards and how do I install them?

Fascia and riser boards are thinner and wider versions of deck boards that serve as a non-structural covering for rim joists, stair risers, and stringers. They are sometimes referred to as “skirts” or “trim” boards.

Because fascia and riser boards are thin, Fiberon recommends installing them using 2.5" #8 or #10 stainless steel or composite screws installed flush to the board surface. We do NOT recommend using Cortex face fasteners because there is simply not enough material available for the screw to be properly seated.

Here are the steps to follow when installing fascia and risers:

  • Fascia: Install screws at a maximum 12-inch interval, with three screws across the face at each interval.
  • Risers: Install screws at a maximum of 12-inch interval, with two screws across the face at each interval.
  • In addition, when installing Paramount PVC fascia, apply a zigzag bead of high-quality exterior adhesive to the entire length of the back (the smooth side). Be sure the adhesive is applied within 2 inches of the edges and ends.
  • Do not over-tighten screws. Buckling or cracking could result.
  • Do not install screws within 1.5 inches of board end or within 1 inch of board side as immediate or eventual cracking could result.
  • When installing in temperatures of 50°F (10°C) of higher, install with 1/8 inch (3mm) spacing between the edges and ends.
  • For temperatures below 50°F (10°C), install with 3/16 inch (5mm) spacing between edges and ends.

What are the differences between Symmetry and Horizon decking?

Both collections feature the same PermaTech® cap layer for stain and fade resistance and durable composite construction; however, each has its own distinct look.

Symmetry has a matte finish and subtle multi-tonal streaking. Offered in four earthy colors (Burnt Umber, Cinnabar, Graphite, and Warm Sienna), Symmetry delivers a rich, understated look. Horizon has a more traditional finish and dramatic multi-tonal streaking. Choose from Ipe, Rosewood, Castle Gray, and Tudor Brown.

How do I remove tree sap from my decking?

Because tree sap is especially sticky, neither ordinary deck cleaners nor power washing will work. We recommend using WD40 to remove the sap. Be sure to follow all manufacturer’s instructions carefully. Please note that WD40 also is effective in removing the labels that are found on the boards when they arrive at the job site.

How do I remove the label adhesive from my Fiberon deck Boards?

When you remove the labels that come standard on our deck boards, there may be some adhesive left behind. We recommend WD40, denatured alcohol or PVC pipe cleaning liquid as the most effective means of removing this adhesive. Traditional deck cleaner or power washing may not remove the adhesive completely.

I accidentally chipped a piece of my deck board. Is there a way to repair it?

While Fiberon decking is resilient, some outside sources can damage it. Certain minor issues can be fixed with a soft bristle brush or heat gun – this is not a guaranteed fix. Or, since Concordia PE composite decking is reversible, you may opt to remove the chipped / scratched board, flip it over and re-install it.

If you’re not sure what the best course of action is for your particular situation, we recommend contacting our Technical Services staff via email.

Tools needed:

Heat gun

Heat-resistant gloves

Soft bristle brush (not recommended for Concordia Symmetry Collection, Sanctuary or Good Life decking.)

Heat Gun Method

Make sure deck is clean and dry. Begin heating of the deck using a heat gun set to 900 degrees Fahrenheit, working in small sections if it is a larger area affected. Keep the gun at least one inch away from the deck surface and keep the gun in motion over the area to prevent overheating of the surface in any one area. 

If you overheat the surface, it can lead to scorching, bubbling or blistering of the polyethylene capping. You will start to see the surface scratch fade visually from the deck surface. When the scratches begin to fade, back the heat gun away to prevent from overheating the area. Return the heat source if no further fading is seen.

Using a heat gun may result in a sheen over the repair site. This should dull down over time.

Soft Bristle Brush Method

Using a soft bristle brush in the direction of the grain is a safer way to go. Start with light pressure and increase as needed, keeping in mind that getting too aggressive can give the area a burnished sheen at the repair site. This should dull down over time.


  • Overly aggressive continuous brushing will result in a sheen with any of our products. This will be more noticeable on darker colored decking. With weathering, the sheen will diminish over time.
  • With the heat gun, extreme care must be taken to ensure the surface doesn’t get too hot, or all small details will be smoothed out. Practicing on scraps or in an inconspicuous area is highly recommended.
  • If there are gouges that go below the capping into the core of the material, the heat gun can help with the appearance around the gouge but the core will still be visible. 

What cleaner is best to use to keep my composite railing like new?

To clean your composite railing and maintain its like-new appearance, we recommend using Fantastik®, Mr. Clean® Magic Erasers or DeckMax PVC Revitalizing Wipes.

How much gap should I leave for expansion or contraction when installing?

As temperatures fluctuate, composite deck boards will naturally experience thermal expansion and contraction. That’s why the board ends should never be installed tight against one another. There should always be a slight gap. How much of a gap? That will depend upon air temperature at the time of installation 

For areas that are subject to significant temperature swings, we recommend installing your deck boards using surface fasteners. First, ensure that the deck boards are aligned properly. Then, install a fastener in the middle of each board length to prevent shifting during thermal expansion and contraction.


What can I use to melt ice and snow on my deck without damaging it?

The best thing for removing ice and snow is a calcium chloride-based “ice-melt” or rock salt. If you’re unsure about what type of ice-melt you’re looking for, search for a product that has the phrases, “safe for concrete”, “safe for flagstone”, and “will not kill grass” in its description. Do not use ice melt with an added colorant. The dyes can stain your composite decking. Never use sand on Fiberon Decking. Sand abrasion can grind into the decking and permanently damage the surface.