Building with composite

Working with composites

When non-wood deck lumber first hit the market 20 years ago, it was 100 per cent plastic. This material was incredibly heavy and was prone to gumming up blades and bits if it overheated during a cut. It was also insanely expensive. But today’s composites are dif­­­­­ferent because they’re just that–composites made of a blend of wood fibres and plastic. The addition of wood fibres makes the material much easier to cut, drill and rout. It also improves the appearance and underfoot traction of the product. It’s easy to keep your footing on a modern, composite deck, even when it’s wet, which is why I used composite to build my swim platform.

When you find you have a project that could benefit from using composites, there are some options to consider. You’ll have to choose between hollow composite extrusions or solid composites. The issue isn’t just about the lighter weight and lower cost of extrusions compared with solid composites; it’s also about how you’re going to work the material and the final look you want to achieve for your project.

Extrusion composites have hollow cores, which means they all come with end caps and strips to hide what’s going on inside. No problem there, except this feature restricts your creative options. You’ll need to go with a solid composite if you want to rout a bullnose profile on the overhanging edges of your boards, for instance. The same is true if you want to create custom-milled chamfers on the edges of posts or joints between deck boards.

Hollow extrusions are also much more rigid than solids, so boards can’t be bent for curved designs.

I prefer solid composites to hollow extrusions because of appearance and creative options. Solids are the most like real wood. One unique challenge of working with solids, however, is the need to keep deck boards going down straight. This is true with all decks, but especially true for composites because the stuff is so flexible. The first board you lay down is especially crucial. Take all the time necessary to anchor it perfectly true because it’s going to set the stage for all that will follow.

Put your composite deck or outdoor structure together right, give it an occasional scrubbing and it will serve you well. New varieties offer an enhanced appearance that looks less like plastic and more like real wood–all without the ongoing maintenance liability. A composite deck may be a little on the high-priced, high-tech side, but if it saves you time on your knees with a paintbrush, then that might be a pretty good deal.