Composite decking has become an extremely popular alternative to timber over the past years because it’s environmentally friendly and it comes in many different wood grain patterns and rich colours. Aside from helping save forests and having the choice of aesthetic designs and colours, composite decking is known for its durability because it resists fading, scratching and rotting. However, even though composite decking can withstand wear and tear far better than real timber like cedar and redwood, like any surface exposed to the elements, composite decking is still prone to fading, greying, warping, and other undesirable effects. Composite decking is a low-maintenance option, but it is not completely maintenance-free. Composite decking is also prone to mold and mildew because it’s made of wood and plastic. To prevent these adverse consequences and unsightly appearances caused by damaging UV rays, weather and moisture, stain your composite decking to maintain it and keep it looking great throughout the years.

Before you start staining your composite deck, you need a composite deck cleaner or any high-quality wood cleaner and a composite deck stain to restore colour to your faded composite decking. Choose a deck stain with mildew-resistant coating (i.e. mildewcides or mold inhibitors) to protect your composite decking. Likewise, deck stains with zinc particles naturally fight against mildew. Avoid film-forming or solid deck stains because these begin to chip and peel away after a few months. Film-forming stains are also prone to mildew because they create a film over the surface that traps moisture.

You also need a bristle brush, pad applicator or roller, roller pans and a nap roller cover. For safety and protection, use chemical-resistant gloves and protective apparel. Also, prepare the following: broom, drop cloths, rags, hose, high-pressure nozzle, paint can opener, paint tray and liner, painter’s tape, plastic sheeting, pressure washer, pump sprayer and stir sticks.

Once you have all the tools and materials you need, clean the composite decking before applying the composite deck stain. The surface must be completely cleaned; otherwise, applying a stain to a dirty surface may make the composite decking appear dark and grimy because the composite deck stain will trap the dirt and make it impossible to clean. Sweep off dirt, leaves and other debris from the deck. Don’t use a shovel or any tool with sharp edges to dislodge fragments or accumulated dirt from your deck. Then, using a pressure washer and a composite deck cleaner, wash away all dirt, mold and mildew. Follow all label instructions. It is important to ensure all mildew is removed before staining the deck so that mildew is not sealed in below the surface.

After washing with the composite deck cleaner, thoroughly rinse all surface areas with clean water. Check that the deck surface is completely clean and dry before you apply the composite deck stain. In some cases, this might take a few days depending on the weather. Then, use drop cloths or plastic sheeting to cover plants, grass, furniture, deck trim, concrete and other items you don’t want stained.

Use a high-grade composite deck stain that penetrates well. Stir the product thoroughly and make sure all colorants mix evenly into the stain. Similar to the deck cleaner, check that you follow all guidelines on the label. Use a brush, pad applicator, roller or a quality pump sprayer to apply a coat of composite deck stain. Do not over apply because any excess product will not just evaporate away. When using a brush, back brushing guarantees even application. Always spread the stain over vertical surfaces first and be careful to avoid dripping stain onto the floor and other horizontal areas. After half an hour, brush or roll excess stain that might have pooled on the surface of the deck. If the splotches of excess product are not removed, they might remain as sticky, shiny spots on the surface, making your deck look tacky.

Some recommend applying a clear sealer over the deck stain to make your composite deck more durable, but composite deck stains already contain UV-shielding pigments and mildewcides, making them an effective protective finish for your composite decking. Some clear deck sealers or finishes do not attach well to a composite deck stain and may cause premature peeling and flaking off from the deck. Stains and sealers are designed to adhere to bare wood but not to each other, so it’s not advisable to apply a sealer over a composite deck stain.

Clean up and properly seal and dispose of containers as well as used water, brushes and roller covers. Allow sufficient drying time before subjecting the surface to foot traffic and placement of furniture and potted plants. Your composite decking looks brand new and there is no need to stain in another two to four years, depending on the type of composite decking and how the deck was constructed, the amount of foot traffic, the constant rearrangement of furniture and exposure to heat and rain. You can maintain your composite decking using a composite deck cleaner at least twice a year. Also, keep your deck dry because standing water can stain your deck.