How to Use Composite Decking Screws

Selecting the Right Screw Type

When it comes to building a composite deck, choosing the correct screws is paramount. Composite decking materials are made from a mix of wood fibers and plastic, which requires specific types of screws designed for this unique combination. The ideal screw should be corrosion-resistant and have a sharp point to easily penetrate the composite material without splitting it. Stainless steel or coated screws are recommended due to their resistance against rust and corrosion caused by moisture and weather conditions. It’s also important to consider the screw length, which should be long enough to securely fasten the decking board but not so long that it protrudes through the other side.

Preparing the Decking Boards

Before installing composite decking screws, ensure your decking boards are clean and free from debris. This will help in achieving a smooth and secure installation. If you’re working with pre-drilled holes, make sure they are the appropriate size for the screws you plan to use. Pre-drilling is essential as it prevents the composite material from splitting when the screw is driven in. Typically, the hole should be slightly smaller than the screw shank to provide a snug fit. Additionally, consider using a countersink bit to create a slight depression around the screw head, ensuring a flush finish.

Common Mistakes to Avoid

One common mistake is over-tightening the screws, which can cause the composite material to split. Always use a drill with a clutch setting to prevent this. Another frequent error is failing to use a rubber washer under the screw head, which can lead to water seepage and potential rotting. Always use a rubber washer to create a watertight seal. Lastly, do not skip the step of pre-drilling holes; doing so increases the risk of splitting the composite decking boards.

The Final Installation

Begin by laying out the decking boards on the prepared joists. Ensure they are spaced evenly to allow for expansion and contraction due to temperature changes. Start at one end of the deck and work your way across, securing each board with the selected screws. Drive the screws into the center of each board to distribute weight evenly and minimize the risk of splitting. Tighten the screws just enough to hold the board in place but not so tight that the screw head is fully recessed into the composite material.

Reference Materials

How to Build a Composite Deck, This Old House