Retrofit your deck with composite

Starting over

The most tedious part of replacing deck boards is getting the old ones off, and for this job I had the help of an eager worker. My nine-year-old son, Joseph, asked to take on the work when I began my Trex transplant. I never guessed how fast he’d become after some practice.

Joseph’s forte is unscrewing Robertson deck screws that have been weathered for a dozen years, with heads that carry the residue of two or three refinishing campaigns. “I definitely prefer an impact driver instead of a drill because the driver grabs screw heads much better than a drill,” Joseph says. “I only clean screws that the driver bit won’t grab on the first try.” I gave Joseph a scratch awl to clean the screw heads. The pointy tip is perfect for the job. Sharpen the awl on a bench grinder as required to keep it in shape.

Installation station

You won’t have spent much time installing composites before you discover that they’re much more flexible than real wood. This feature means you need to pay attention to keeping them straight as they are fastened to the structure. It’s especially important to get the first row correct, and for this you can’t beat a tight string. Pull it from one end of your deck to the other, just slightly higher than the thickness of the deck boards. Put your first course of boards down, align them to the string, then anchor them straight. You might think that subsequent rows of boards will automatically be straight too, but that’s not necessarily so. Before every second or third row goes down, take a look along the entire edge at deck level, from one end to the other. Have a helper pull the wayward board in or out until it’s as straight as possible, then lock it down. I use a BoWrench and rubber mallet to wrestle deck boards into alignment. The work is easier than with real wood because composites don’t have the same internal springiness.

As you work, understand that expansion can be an issue with composites. Unlike wood, composites don’t change size much with fluctuations in moisture. Shrinking composites aren’t likely to be a problem, but expansion caused by heat might be. It’s essential that you include sufficient gaps between boards and at their ends. The amount of space required varies with different products, and with the temperature of the day you put the boards down. Ignore this detail and you could get a buckled, bumpy deck on hot days.

Most people don’t anticipate how much work goes into maintaining wooden decking. They’re surprised, then overwhelmed enough to live with grey, peeling decks. Just because you’ve opted for a wooden deck in the past doesn’t mean you need to stick with it until all the lumber is compost. Composites offer a way out, even if they’ll never be quite as classic as the newly finished real thing.