Plastic deck lumber is fantastic for outdoor projects

Two years ago, I replaced my moldy old deck with a shiny new one made from plastic-wood composite material (TimberTech), and it looks as good right now as it did when I installed it. And all I’ve done for maintenance is a yearly scrub with mild soap (Simple Green) and warm water.

That got me thinking about building outdoor furniture with this material. I mentioned that to my friends at Woodcraft magazine, and soon I was writing two articles for them, both in the latest issue (June/July 2019), on newsstands now. One article takes a broad look at all of the plastic-based lumber out there and how to work with each type, and in the other I build nice outdoor project: a bench and planter combo adapted from my recent book, Build Stuff with Wood. 

Here’s the bottom line on plastic wood: While there are a number of plastic-based products out there, only two are really good for woodworking-style projects. One is all-plastic (HDPE) lumber, used mostly for big commercial projects like docks and boardwalks. The other is composite decking, but not the kind with a plastic cap on the outside. That type looks weird when you cut into it. The best type is uncapped composite lumber.

One other bad type for furniture projects is PVC-based lumber (like Azek). It’s just too flexible.

The all-plastic stuff is the premium product, available in bright colors that will stay that way for decades in sun, rain, and cold. The stuff even gets grippier when wet.

For a more woody look, there are uncapped composite boards. They are more widely available and significantly less expensive, produced in wood tones with more of a matte finish that fades a little over time, like real wood.

Best of all, the plastic in both of these materials is 100% recycled, pulling some trash out of oceans and landfills.

As for how to use plastic lumber, that’s all good news too. It cuts just like wood, with any common woodworking tool, including handplanes. The only thing that doesn’t work on plastics and composites is glue. So it’s all mechanical fasteners for joinery: screws, pocket-screws, cross-barrel bolts, normal nuts and bolts, and dowel for alignment. Be creative, choose the right screws (GRK screws from Home Depot are coarse and weatherproof, and grip plastics and composites really well), and you can build almost anything.

The only real downside is getting your hands on the stuff.  These days, PVC and capped composite boards dominate lumberyards while all-plastic and uncapped composites are available by special order only.  It’s worth it though. Here are the best sources and some typical prices.

All-plastic (HDPE): Price for a 2x4x12 is roughly $47-60 depending on color, not including shipping. Sources are (shown) and, both of whom are happy to send you samples for a minimal price.

Uncapped composites: Price for a 2x4x12 is roughly $50. Since these products can be ordered from local lumber retailers, shipping is built into the price. The brands to ask for are MoistureShield Vantage and Tamko Evergrain. Check manufacturer’s websites (or call customer service) for retailers near you.

As for what’s possible and how to make it happen, here are some highlights. For more info, check out the June/July 2019 issue of Woodcraft magazine.

All-plastic lumber is pricier than wood-plastic composites, but the colors are endless and brilliant, and the material will last for decades outdoors. These projects were adapted from my recent book, Build Stuff with Wood.


I made the same bench and planters from wood-plastic deck boards too, which are a bit thicker and woodier. I like this look just as well.



Pocket screws work great in plastic wood.


Normal outdoor screws work awesome too. I like the GRK line from The Home Depot.


I used trim-head screws to assemble the planters. Those look nice and neat.


I used long plug-cutters by WoodRiver to make long-straight plugs from the same material, and used them to hide screws when I wanted to.


Soften the plug and hole with an inexpensive heat gun, and then tap them in.
You can cut plugs close with a saw or razor, and then trim them flush with a block plane.
You can use long plugs to hide pocket holes too!
To make the cut edges on plastic lumber look just like the rounded original edges, I gave them a similar roundover on the router table.
Here’s a cool trick for composites. It looks a little lighter where you cut it then it does on its original molded surfaces. To make the inside look more like the outside, just heat it up with that handy gun.




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