The Eco Deck

Photo: istockPhoto.com/Brigitte Smith
Choose the right wood and finish for healthy, beautiful and long-lasting decks

The best decking materials are natural, long lasting, minimally processed and locally grown or milled. Choosing lumber from responsibly managed forests supports the environment, since trees absorb CO2 and solidify it in the wood. Lumber stores this carbon, which would be released if trees rotted or burned. Here’s how some popular choices stack up:

More Ideas for Decks 

• Find out how to make a wood deck
  last up to 50 years
• Choose a low-impact deck finish
• Learn how to shop for sustainable wood.

PRESSURE-TREATED LUMBER

With its trademark greenish hue, this lumber is widely available, strong and potentially long-lasting. Milled from spruce, pine or fir made rot-resistant by driving in preservatives (such as alkaline copper quaternary and copper azole; arsenic was discontinued in 2003). It’s safe indoors and out (it’s often used for a deck’s superstructure, topped with other materials), but not for food-contact items, garden mulch or burning. After handling, wash hands with mild soap. As with all woods, wear a dust mask while cutting and sanding. 

Cost: $ | Greenness:  The preservative is both a blessing and a curse: Without those chemicals, the wood wouldn’t last as long.

HEAT-TREATED SOFTWOODS

An up-and-coming, chemical-free approach for increasing the strength and rot-resistance of softwood lumber. The process heats the wood (typically southern yellow pine from the U.S.) to over 200°C, making it roughly 25 times more resistant to rot than untreated pine and about 15 per cent pricier than cedar. Not yet widely available in lumberyards. 

Cost: $$$$$  | Greenness:  Reduced chemical treatment is great, but requires increased energy for processing and transportation.

CEDAR

Lightweight, naturally rot-resistant and easy to work with, though western red cedar creates transport emissions if sent to eastern markets. Eastern white cedar is available through small mills (red and white cedar have a similar lifespan). Although not treated with preservatives, cedar dust is more likely to cause allergic reactions than other species. 

Cost: $$$ to $$$$$ depending on distance from mill | Greenness:  A hardy, readily available wood with minimal chemical treatment.

EXOTIC HARDWOODS

Marketed under names like ipe and tigerwood, these hard, strong, heavy and prestigious deck woods typically come from Central and South America. Tropical wood is essential for the global water cycle and tempering the climate in general, so be sure the wood is certified by the Forest Stewardship Council (FSC) or Rainforest Alliance, since many tropical forests are being over-harvested (see “Signs of sustainable wood”). By purchasing from properly managed forests, you’re supporting conservation. Exotics weather to the same grey as domestic softwoods when left without a finish. 

Cost: $$$$ to $$$$$ | Greenness:  for certified wood,  for uncertified. Tropical wood creates a lot of shipping emissions.

COMPOSITE AND PLASTIC LUMBER

High recycled content and freedom from maintenance and rot are the reasons these options are growing more popular. Composites are made of a 50/50 blend of recycled plastic (typically shopping bags) and recycled wood fibre (usually from old shipping pallets). Composites cut and drill just like regular wood, though they’re much heavier and not as rigid. Sold as solid boards (which look less mechanical) or hollow extrusions. Plastic lumber eliminates the possibility of mould, which sometimes grows on composites. Neither composites nor 100-per-cent-plastic lumber are resilient enough for use as floor joists, posts or beams. Real wood is still required for all structural parts; composites go on top. 

Cost: $$$  for hollow extrusions; $$$$$ for solid boards | Greenness:  Recycling is energy-intensive. Otherwise, these are durable, readily available, a good use of waste and often recyclable if returned to the manufacturer.

Get more ideas for eco-friendly home improvement projects, plus rebates for green updates, at EcoLiving.

First published in Issue 2 of EcoLiving magazine, produced by Green Living for Scotiabank.

 

 


Steve Maxwell is a syndicated home improvement and woodworking columnist. Visit his website to get more deck tips and how-to videos from “Canada’s Handiest Man”. Materials reviewed by Derek Satnik, green building consultant and chief innovation officer of Mindscape Innovations in Kitchener, Ont.