Galvanized fasteners: Galvanizing is the most common treatment for metal fasteners used outdoors. But there are differences in the methods and materials used in galvanizing. The best process is hot-dip galvanizing, in which the fastener is dipped in molten zinc. Hot-dipped galvanized nails are best for most decks.
Stainless steel fasteners are extremely resistant to degradation. Use them near salt water or other regularly wet or corrosive conditions.
Aluminum fasteners are not recommended for use on decks.
Nails: When nailing on the decking boards, ring- or spiral-shank nails provide a much better grip than common wood nails. (See Illustration 1.) On the other hand, they can be difficult to remove if you need to replace decking.
Screws: Stainless steel, anodized, or hot-dipped galvanized screws are excellent choices for fastening decking. (See Illustration 2.) Screws for this purpose often are referred to as decking screws. They are available in 2- to 3-inch lengths, with either Phillips or square-drive heads. Do not use regular black-coated screws intended for wallboard or other interior purposes.
Bolts and masonry connectors: The strongest fasteners for joining structural members are machine and carriage bolts. (See Illustration 3.) Machine bolts require a washer on both ends; carriage bolts require a washer only on the nut end. Carriage bolts have a rounded head. Use 1/2-inch bolts unless directed otherwise. Lag screws are necessary when access is restricted. Use anchors when fastening ledger boards to masonry or concrete foundations.
Post and joist connectors: Ready-made lumber connectors have simplified many aspects of deck construction. Seismic (or hurricane) anchors help secure joists to beams. Post anchors tie posts to the concrete piers via a J-bolt, eliminating the need to embed posts in concrete. Joist hangers offer a secure pocket for joists, while post caps allow a quick means of supporting beams on posts. (See Illustration 4.)
Galvanized deck hardware (bolts, nails, lag screws and bolts, joist hangers, etc.) is inexpensive and widely available. Nails start at 88 cents per pound, and you can buy deck screws in bulk for $4.20 to $7.50. Hardware that performs the deck's heavy lifting - truss hangers, strap and joist hangers and rafter ties - range from $.35 to $3. Stainless steel hardware and fasteners are not available in all areas, but you should expect to pay at least twice the price of galvanized products.