Installation basics for composite decking
By Brent Gwatney

Composite materials can be easily machined and installed with standard hand and power tools as without a grain the material will not split. When using these materials, they should always be installed according to the manufacturer’s installation instructions, paying close attention to maximum allowable uniform live load and member span requirements.
Understanding local code regulations and substructure requirements for spans are essential with composite decking. Typically, wood-plastic composite (WPC) decking boards require a 406-mm (16-in.) on-centre (oc) joist span for installation and 305-mm (12-in.) oc joist span for diagonal installation. Composite decking follows underlying support surfaces more closely than wood planks do. Therefore, it is important to ensure joists are level with one another to avoid a wavy surface appearance.
For some composite decking products, stainless-steel trim head screws can minimize the chance for metal corrosion or staining on the material. If a project requires screws to be hidden, they can be countersunk to draw up excess decking material that can then be brushed over the screw head and tapped with a hammer for the desired look. Some composite decking is also compatible with hidden fastener systems.
The type of warranty offered with composite decking varies by manufacturer. Many WPC decking materials have 20- or 25-year limited warranties, while some brands offer a standard limited lifetime warranty.
Builders can benefit from this decking material’s durability, design flexibility and ease of installation for various decking and landscaping projects. The end result is an inviting deck built with sustainability in mind.
Brent Gwatney is senior vice-president of sales and marketing for MoistureShield, a composite decking materials manufacturer in Springdale, Ark. He can be reached via e-mail at bgwatney@aert.cc.