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How to Install Composite Decking?

When installing composite decking yourself, it is extremely important to follow the installation guidelines provided by the manufacturers. This is mainly due to the thermal expansion and contraction that composite decking experiences as a part of a plastic plastics product. Composite decking will expand and shrink from summer to winter as it cools and heats up.

The correct spacing must be provided to allow movement throughout the year and lifespan of your composite decking. Before installing your composite decking it’s important to always remember 3 key points, expansion, water drainage & good airflow. Composite decking expands in the heat and contracts in the cold. Since every area in the UK has different temperatures you need to allow up to 48 hours for the composite decking boards to climatise to the weather conditions in your location and carefully taking into consideration the expansion and contraction gaps required during installation.

Water drainage & good airflow is also important. This is why Ultra Decking recommends a raised deck area with a 5% slope and a raised deck of a minimum of 300mm. If you do choose to complete a ground level deck it’s important to allow a slope and area for the water to drain off easily. Note, please ensure that the drainage between the base is good; otherwise, this would cause long term rot of the joists and deformation of the decking.

Important note – Don’t forget the gaps, a 20mm expansion gap should be left between the deck and any walls or fixed objects, 3mm gap side to side of all deck boards and a 6-8mm gap on any joint butt (8-10mm gap left below 10 degree) with a 6mm gap left at the end of the boards or meeting a facia or angle trim. However, it is important to check with the manufacturer’s installation guides to double-check.

Upon installation, one thing to note before starting your install is to open your boards up and allow them to settle in the climate for at least 48 hours.

If storing the boards please ensure the boards are flat, covered and supported at 30 cm intervals.

Ensure you have enough materials to cover your new decking project. This is a common error due to incorrect measurements or not creating a detailed plan.

We also recommend adding at least 5% wastage to your calculation or measurements. Add at least 15% extra materials for diagonal areas due to higher wattage.

Always handle boards with care picking up and placing down rather than sliding and dumping, it’s recommended to carry a board on its edge.

Decking joists supporting your new composite decking must be spaced no more than 30 cm or 300 mm

Start clips are highly recommended to line up your first board quickly and easily and the rest will flow thereafter.

When levelling the joist, it’s important to keep the butt joists at the same height and use 2 hidden fasteners on the double joist.

When installing a Balustrade or railing post always ensure you leave a 6 mm gap for thermal expansion.

We recommend corner trims with hollow composite decking for a neat and clean finish.

Double up joists for butt joists across the deck, always ensure to level both double joists to the same height and faster with at least 4 screws

Hidden fasteners provide a professional neat finish with no viable screw heads, as well as providing a safer decking area for pets and children.

When installing with hidden fasteners, start at the house by face-screwing the first board, then screw a hidden fastener clip into the groove on top of every joist and then slide the slide the grove of the next board into the clip.

A power mitre saw is recommend for speed, accuracy and not to mention for edging and corners.

For a full detailed installation guide please download now or order a sample and heck your measurement and quality.