A Weather-Proof Deck

Article Tools

Image Gallery

Print

E-mail

Comments

RSS

Years ago, I swapped my framing hammer for a power-driver (see page 33) and I now fasten decks and most all else I build with self-tapping screws. It ain't cheap. A good drill/driver costs at least $100 and screws are sold by count rather than weight at better than ten times the cost of nails. But power-driving takes less muscle and experience than hammering. It goes faster in the long run, dings and splits fewer boards, and—most important to me—the screws can be backed right out, while a nail sunk to the head, holding a steel deck plate onto good wood, is there to stay. Deck screws let me correct my inevitable amateur-builder mistakes and they make repairs and rot-replacements easy. Just be sure to get the silver deck screws,not the similar, but thinner, black drywall screws meant for inside use. Deck screws are less brittle than drywall screws and come in nonrusting metals, so they won't corrode, "weep," and stain your wood.

"Backyard Projects" continues with "Natural Paths and Walkways."

Lumber and Hardware

Pressure treated lumber, or PT, used in most decks is made from standard "dimension lumber"—square timbers and nominal 2" thick boards cut in even-inch widths from 2" to 12" and in even-foot lengths from 8' to 20' or more—from a good-building wood such as one of the southeastern yellow pines or western Douglas fir. It is heated and dried to less than 10 percent moisture content in a big kiln, then saturated under pressure for an hour or so in a bath of hot preservative. By standards promulgated by regional wood-treatment associations, the lumber must be impregnated to at least 85 percent of its thickness and to a preservative content of between .25 to .60 pounds per cubic foot of wood. Low-rated timbers are cheaper than the higher rated. But using them in your deck is false economy. A .40 rating certifies that lumber will survive full-time ground contact for 40 years. Kept off the ground and treated annually with preservative and waterproofer, the wood should last as long as the rest of the house. Use .25 outdoors, but for sheltered applications (a roofed deck), and save .60 for especially hostile environments such as along the ultra-humid Gulf Coast, inland in subtropical southern Florida, or as posts for a freshwater dock or saltwater pier.

The standard wood preservative is CCA, or Chrome-Copper-Arsenate. It is a long-acting but relatively benign heavy-metal poison—but a poison nonetheless—that kills mold spores and bacteria and deters bugs and gnawing animals. Older formulations give the wood a corroded-copper-green tint that fades to a pleasant silvery grey in 6 months or less. Newer compounds lack the green color.

A new product called ACQ just now coming to market reportedly works well without incorporating poisonous chromium and arsenic. It does use a copper compound as a fungicide, so remains moderately toxic.

RSS | Comments | E-mail | Print

GET MORE INFORMATION ON THIS TOPIC:

CREATING CUSTOM GARDEN SPACES ON CD-ROM'

CD Rom

Our Price: Price: $19.95

• Browse Books

CREATING CUSTOM GARDEN SPACES E-BOOK'

Downloadable PDF

Our Price: Price: $10.00

• Browse E-books