By MATT MAURY

If this is the year for building a new deck or repairing an old deck, be prepared to consider a wide variety of new products.

For many years, the prevalent material for Pacific Northwest decks has been "Outdoor Wood," as pressure-treated lumber has been marketed. Then in the mid-1990s, the chemical preservatives, particularly arsenic, in the pressure-treated lumber came into question as a potential health hazard.

Although the Environmental Protection Agency has not labeled the use of the arsenic-treated lumber a risky product, it has worked with the American Wood Preservers Institute to issue a list of protective measures to take when working with the lumber. Both the EPA and the wood products industry recognize the negative connotation arsenic has, so there is a new type of treatment being used - ACQ - that doesn't contain arsenic. Both types will be available over the next 18 months, as the arsenic-treated (CCA) products are phased out. Consumers should be aware of the differences when making purchases.

All the concern over pressure-treated lumber has caused homeowners to look for alternative materials. Of course, there are still the historic options of cedar and redwood lumber. The fact that these species are both beautiful and long-lasting is over-shadowed, for many folks, by their prices - up to twice the cost of CCA-treated lumber.

This has opened the door to a variety of new products generally referred to as "composite decking." Probably the most well-known brand of composite is "Trex" because it was the first one on the market. In the past few years at least 14 companies have introduced these alternative decking products, although not all are currently available in the Northwest. They are made of wood fibers and plastic in standard sizes for decking. The major characteristics of these products include that they: won't split, twist or rot; are splinter-free; are ready to install without painting or staining (although color does fade over time); require only standard woodworking tools; expand more than solid wood as temperatures rise (so require installation to allow for wider gaps between pieces); absorb heat from the sun (so may get very warm in direct sunlight); must be installed with the manufacturer-specified fasteners to avoid surface distortions; and cost 20 percent or more than pressure-treated lumber.

Since there are no "industry standards" for these composite products, each manufacturer has unique specifications and designs. Some firms produce solid products while others make hollow ones. These differences are worth noting.

Solid composite lumber is void-free like "real" wood so can be cut to any length, requires joist spacing 16 inches or less on center to be stable, and is heavier than lumber, which may require a new design when replacing an existing deck.

Hollow composite lumber is open under its surface requiring special trim pieces to hide the ends, made stiffer than lumber by its I-beam design so it can span joists up to 24 inches on center, and is lighter than wood and easier to handle.

The installation of a composite product will not eliminate the need for regular deck maintenance. Mold and mildew will occur as on real wood, especially in areas continually in the shade. A yearly washing with a mixture of detergent, bleach and water, as recommended by the decking manufacturer, may be required.

Since all the composite products fade as they weather, it is wise to look at faded samples prior to making a color choice. Some products accept paint and stain while others don't, so be sure to research this before making a buying decision.

A final consideration in making a product selection is in the accessories that are available. Some manufacturers have posts, railings, benches and fencing options, while others are limited to decking alone.

Before heading to a building materials supplier, it might be helpful to research some decking options on the Internet. Searching for "redwood decking," "cedar decking," "American Wood Preservers Institute," and "wood composite decking" will provide many manufacturers' Web sites with consumer information.