Laying Composite Decking: A Step-by-Step Guide

Composite decking is an excellent choice for homeowners looking for a durable, low-maintenance option. Unlike traditional wood decks, composite decks resist rot, insects, and fading, offering years of beauty and functionality. If you’re considering laying composite decking, here’s a step-by-step guide to help you through the process.

Gather the Necessary Materials and tools;

Composite deck boards
• Joists (pressure-treated wood or metal)
• Decking screws or hidden fasteners
• Measuring tape
• Saw (circular or miter)
• Drill
• Spacers (typically 3/16 inch)
• Safety gear (goggles, gloves, and ear protection)

Prepare the Ground:
Ensure that the ground where you’ll place the deck is flat and free of debris. If you’re laying the decking over an existing surface, make sure it’s stable and level.

Set Up the Joist Framework:
Lay out the joists at 16-inch intervals, ensuring they are parallel and level. This will provide the necessary support for the decking boards.

Begin Laying the Boards:
Start from one corner and work your way out. Use spacers between each board to ensure even gaps. This allows for drainage and expansion.

Secure the Deck Boards:
For a clean look, use hidden fasteners which slide between the boards. Alternatively, you can use composite decking screws. It’s important to ensure each board is secured to every joist beneath it.

Stagger the Seams:
If your deck is wider than the length of your decking boards, you’ll need to stagger the seams where two boards meet. This creates a more appealing visual pattern and adds strength to the deck.

Finishing Touches:
Once all the boards are in place, you may want to add trim or fascia boards around the deck’s edges for a polished look. Additionally, consider using railings or balusters for safety and aesthetics.

Maintenance:
While composite decking is low maintenance, it’s still a good idea to clean it periodically with a mild soap and water mixture. Avoid using high-pressure power washers as they can damage the decking.

FAQ’s

How to Lay Composite Decking Tiles on Grass?

Laying composite decking tiles directly on grass is not recommended because it can lead to uneven surfaces and potential damage due to moisture and soil movement. Instead, it’s advisable to:

•   Remove the grass and a few inches of soil.
•   Install a gravel base and compact it to create a stable, flat surface.
•   Place a weed barrier fabric over the gravel.
•   Lay the tiles on this prepared surface, ensuring they are securely interlocked.

How to Lay Composite Decking on Soil?

Similar to laying on grass, direct installation on soil is not ideal. Follow these steps for a better foundation:

•   Clear the area of vegetation and level the soil.
•   Apply a layer of gravel and compact it for drainage and stability.
•   Use a geotextile fabric to prevent weed growth.
•   Install a frame or foundation that can support the composite decking above the ground.

Laying Composite Decking on Top of Wood Decking

Laying composite decking over existing wood decking can be a viable option if the wood deck is structurally sound:

•   Inspect the existing deck to ensure it’s stable, with no rot or damage.
•   Clean the wood deck thoroughly.
•   Consider using joist tape to protect the existing structure from moisture.
•   Install the composite decking boards perpendicular to the existing wood decking for added stability, using screws or hidden fasteners.

For each of these scenarios, it’s crucial to follow manufacturer guidelines for the composite materials being used, as installation requirements can vary. Always ensure adequate ventilation and drainage to prevent damage to the decking material. Safety precautions and adherence to local building codes are essential throughout the project.

Laying Patterns

Laying patterns for composite decking not only contribute to the aesthetic appeal of your outdoor space but also can affect the overall durability and functionality of the deck. Here are several popular laying patterns and considerations for your composite decking project:

Large composite deck on a luxury home – Image: James Pintar

Horizontal or Straight Pattern • Deck boards are laid side by side running parallel to the house. This is the most common and simplest pattern, often chosen for its ease of installation and classic look.
Considerations: It’s essential to ensure proper spacing for expansion and contraction. Also, consider the board lengths to minimise waste.
Vertical Pattern • Similar to the horizontal pattern but runs perpendicular to the house. This pattern can make the space appear longer or deeper, depending on the direction of the layout.
Considerations: This pattern might require more cuts and adjustments at the ends, especially if the deck does not align perfectly with the board lengths.
Diagonal Pattern • Boards are laid at a 45-degree angle to the joists. This pattern adds visual interest and can make the space appear larger.
Considerations: Diagonal layouts require more cuts, meaning more waste and potentially higher costs. Ensure that the joists are spaced appropriately (usually closer together) to support the diagonal span.
Herringbone Pattern • A series of parallel boards are laid diagonally in opposite directions, creating a V shape. This intricate pattern is eye-catching and adds a unique character to the deck.
Considerations: The herringbone pattern is complex to lay out and requires precise cutting and framing, often leading to higher labor and material costs. It’s crucial to plan the layout meticulously to ensure the pattern aligns correctly across the deck.
Picture Frame Pattern • A border (or frame) is created around the edge of the deck, setting off the main decking area. This can be done using the same material in a different colour or orientation.
Considerations: The picture frame pattern requires additional framing and precise cutting to ensure the frame is even and structurally sound. It’s a great way to hide the end grains of the deck boards and can be combined with other patterns for a unique look.
Checkerboard Pattern • Alternating squares of different coloured decking boards are used to create a checkerboard effect. This can be very striking and allows for creative colour combinations.
Considerations: The checkerboard pattern requires careful planning and layout to ensure each “square” aligns correctly. It may also require additional supports depending on the deck’s structure.

Installation Tips:

•   Spacing: Always leave adequate space between boards for water drainage and expansion.
•   Support: Ensure your joist framework is sturdy and appropriately spaced for your chosen pattern, as some patterns may require closer joist spacing.
•   Manufacturer’s Instructions: Follow the specific guidelines provided by your decking material’s manufacturer, as some materials may have unique requirements.

Choosing a laying pattern for your composite decking involves considering the visual appeal, the amount of waste, the complexity of the installation, and the cost. Each pattern offers a different look and feel for your outdoor space, allowing customisation to suit personal preferences and the functional requirements of the area.