The wood decking in this garden designed by Robert Sabbatini, FASLA complements the stone barbecue and retaining wall.
What’s On Deck
A good deck can be the perfect transition between the interior and exterior of your home. Whether you want a great view, a quiet retreat, a backyard bistro or barbecue central, the first step is to choose the right decking materials. The options are wood, including pressure-treated (PT) lumber, redwood, cedar, and tropical hardwoods; composite decking; plastic decking; and aluminum decking.
The most popular, least expensive decking material on the market today is pressure-treated lumber made from southern yellow pine that has been chemically treated to withstand wood-boring bugs, rot and fungus. On the upside, PT lumber is strong, easy to work with and readily available. On the down side, it splinters, warps and rots easily if not maintained; needs to be cleaned annually; and must be refinished every one to three years.
From a sustainability standpoint, there are also a few things to consider. For years, PT wood was treated with chromated copper arsenate, (CCA) which contains arsenic, a toxic chemical. While it’s now treated with less toxic chemicals, using salvaged lumber or woods that naturally withstand bugs and rot, such as redwood and cedar or sustainably harvested tropical hardwoods might be a better choice if the environment is one of your considerations.
Redwood and Cedar
Redwood and cedar are western softwoods that are popular for use in decks because of their beauty and the natural oils and tannins they contain that enable them to withstand rot, decay and insects. Cost and maintenance are the main drawbacks here. Redwood and cedar decks can be expensive, and resistance to decay and bugs depends on the amount of heartwood in the planks. Care includes power washing the deck once a year and applying a coat of finish every three to four years.
Tropical hardwoods such as ipé, cumaru and cambara are durable, beautiful, long lasting and naturally resistant to insects and decay. They’re also dense, difficult to install, and expensive in terms of money and the environmental cost of importing them. Avoid using dark hardwoods on decks that get a lot of direct sunlight because they get very hot. And make sure to buy Forest Stewardship Council-certified tropical hardwood that has been harvested sustainably and legally.
Made of a combination of ground-up wood and plastic, today’s composite decking market features dozens of brands including Trex, TimberTech, and EverGrain to name a few. Benefits include low maintenance (no sealing, staining or painting, but regular scrubbing is necessary to prevent mildew), easy installation and durability. Disadvantages include density, a tendency to expand and contract more than wood in response to temperature changes, and expense.
Environmentally speaking, some composites contain recycled wood and recycled plastic, some do not, and others are a mix. Composite decking itself is not recyclable, and some composites contain PVC, which is not considered an environmentally friendly choice by green building experts. The best way to find out what’s in the products is to read the manufacturers’ MSDS sheets.
Made from plastics such as polyethelyene, polystyrene and PVC, plastic decks are becoming more popular. Plastic is low-maintenance (needs no sealers/finishes), long lasting, easy to clean, splinter-free and resistant to UV rays if treated at the factory. It’s also heavy (dense), expensive and can sag and fade in extreme temperatures (think Arizona in the summer).
Sustainably speaking, while plastic decking is recyclable and some of it is also made of recycled materials, it may or may not contain contain PVC, which is not considered an environmentally friendly choice.