Decks

Decking

The decking material you choose, and the method in which you install it, will impact your deck in several important ways. All decking must provide a comfortable surface on which to walk. The decking must be strong and durable, slip resistant, and uniformly sized. Although wood has been, and remains, the most popular decking material, several other viable materials are available. You can select from aluminum, recycled plastic, or other types of products in manufactured decking, or opt for the material that is challenging wood’s predominance: composite decking. The rapidly growing popularity of composite is due to the more modest maintenance requirements of the material, ease of installation, and an ever-increasing selection of colors and surface treatments, many of which convincingly mimic wood grain, color, and texture. High-end composites are extremely durable once installed, but they are more expensive than most types of wood.

Regardless of the material you choose, you can create greater aesthetic appeal by laying the decking in unusual patterns. Diagonals, herringbones, and other patterns are all more visually interesting than a simple rectilinear style. These types of patterns will, however, entail more effort and greater expense.

You’ll find a comprehensive overview of deck materials and pattern options in this chapter. You will also find information on decking fastener styles, which include a growing number of “invisible” fasteners that hold decking in place without marking the surface of your beautiful outdoor structure.

In this chapter:

▪ Decking Patterns

▪ Laying Decking

Decking Patterns

Decking boards are the most visible element of your deck, and there are a number of ways to install them. You can use different board widths and lay the boards in any of a number of patterns to increase visual interest. The pattern you choose will affect joist spacing and layout. For instance, a straight decking pattern usually requires joists spaced 16" on-center. Diagonal decking generally requires joist spacing of 12" on-center. Parquet and other intricate patterns may require extra support, such as double joists or additional blocking. For sturdy wood decking, always use at least 5/4 lumber. Thinner boards are more likely to twist or cup.

Diagonal decking is one of the simplest alternatives to straight runs, and can be an interesting look—especially if you run the diagonals in different directions on different platforms or levels of the deck. However, diagonal patterns often require joists spaced closer than a straight pattern.

Parquet patterns are visually stunning and best suited to more formal decks, and those that don’t include bi- or multicolored design features. These patterns require double joists and blocking to provide adequate support surface for attaching the butted ends of boards.

Even a straight pattern can be interesting when interrupted with built-in shapes. A framed opening for a tree or large rock requires extra blocking between joists. Short joists are attached to blocking with joist hangers.

Border patterns with mitered corners provide an elegant finished look to any deck. They are especially effective when used around the inside deck edge bordering a swimming pool. Install trim joists to support the border decking.

Laying Decking

Buy decking boards that are long enough to span the width of the deck, if possible. If you have to use more than one, butt the boards end-to-end over a joist. Stagger butted joints so that they do not overlap row to row.

Install decking so that there is a gap approximately

1/8" between boards to provide drainage. You can use a nail as a spacer between rows. Some wood boards naturally “cup” as they age. Lay the boards with the bark side facing down (see page 39), so that any cupping occurs on the bottom side, and to prevent the board holding water on the top.

The common installation method for wood decking is shown here. We’ve limited the discussion to face-screwing boards to joists, but you can nail the boards down as well. However, nailing is rarely used on modern decking because it requires as much work, and nails inevitably pop down the road. Screws are just more efficient. If you do decide to nail boards down, use 10d galvanized common nails, angling the nails toward each other to improve holding power. Composite and plastic deck boards are never nailed down. For a much sleeker appearance, you can choose from the large number of “invisible” fasteners on the market. The technology for these has come a long way and, whether you’re using wood, composite, or another type of deck boards, hidden fasteners are an easy, quick, and just slightly more expensive option than screwing the boards down. In any case, always follow the installation instructions and methods recommended by the manufacturer of the product you select.

How to Lay Decking

Position the first row of decking flush against the house. The first decking board should be perfectly straight, and should be precut to proper length. Attach the first decking board by driving a pair of 2-1/2" corrosion-resistant deck screws into each joist.

Position remaining decking boards so that ends overhang outside joists. Space boards about 1/8" apart. Attach boards to each joist with a pair of 2-1/2" deck screws driven into each joist.

If the boards are bowed, use a pry bar to maneuver them into position while fastening. You can also use a specialized tool (see page 55) to align the a warped board.

Drill 1/8" pilot holes in the ends of boards before attaching them to the outside joists. Pilot holes prevent screws from splitting decking boards at ends.

After every few rows of decking are installed, measure from the edge of the decking board to the edge of header joist. If the measurements show that the last board will not fit flush against the edge of the deck, adjust board spacing.

Adjust board spacing by changing the gaps between boards by a small amount over three or four rows of boards. Very small spacing changes will not be obvious to the eye.

Use a chalk line to mark the edge of the decking flush with the outside of deck. Cut off decking, using a circular saw. Set the saw blade 1/8" deeper than the thickness of the decking so that saw will not cut the side of the deck. At areas where the circular saw cannot reach, finish the cutoff with a jigsaw or handsaw.

For a more attractive appearance, face the deck with redwood or cedar facing boards. Miter cut corners, and attach boards with deck screws or 8d galvanized nails.

Alternate facing technique: Attach facing boards so that the edges of the end decking boards overhang the facing.

Composite Decking

Lay composite decking as you would wood decking (pages 128 to 130). Position with the factory crown up so water will run off, and space rows 1/8" to 1/4" apart for drainage.

Alternate method: Attach composite decking with self-tapping composite screws. These specially designed screws require no pilot holes. If the decking “mushrooms” over the screw head, use a hammer to tap back in place.

Predrill pilot holes at 3/4 the diameter of the fasteners, but do not countersink. Composite materials allow fasteners to set themselves. Use spiral shank nails, hot-dipped galvanized ceramic coated screws, or stainless steel nails or deck screws.

Lay remaining decking. For boards 16-ft. or shorter, leave a gap at deck ends and any butt joints, 1/16" for every 20°F difference between the temperature at the time of installation and the expected high temperature for the year.

Tongue-and-groove Decking

Position the starter strip at the far end of the deck. Make sure it is straight and properly aligned. Attach it with 2-1/2" galvanized deck screws driven into the lower runner found under the lip of the starter strip.

Fit the tongue of a deck board into the groove of the starter strip. There will be approximately a 1/4" gap between the deck board and the starter strip. Fasten the deck board to the joists with 2-1/2" galvanized deck screws, working from the middle out to the sides of the deck.

Continue to add decking. To lay deck boards end-to-end, leave a 1/8" gap between them, and make sure any butt joints are centered over a joist.

Place the final deck board and attach it with 2-1/2" galvanized deck screws driven through the top of the deck board into the joist. If necessary, rip the final board to size, then support the board with a length of 1 × 1 and attach both to the joist. Attach facing boards to conceal exposed ends (photo 4, next page).

T-clip Decking

Insert 2" galvanized deck screws into T-clips. Loosely attach one T-clip to the ledger at each joist location.

Position a deck board tight against the T-clips. Loosely attach T-clips against bottom lip on front side of deck board, just tight enough to keep the board in place. Fully tighten T-clips at the back of the board, against the house.

Push another deck board tightly against the front T-clips, attach T-clips at the front of the new board, then fully tighten the previous set of T-clips. Add another deck board and repeat the process, to the end of the deck.

Cover exposed deck board ends. Miter cut corners of the facing, and drill pilot holes 3/4 the diameter of the screws. Attach with 3" galvanized deck screws.

Fiberglass Deck Systems

Place a length of retaining clips on top of the first joist. Center it on the joist and fasten with 2" galvanized deck screws. Attach lengths of retaining clips to the subsequent joists, so that the clips are perfectly aligned with the first length of clips, creating straight rows.

Place the open face of a decking board perpendicular to the joists, resting on top of a row of clips. Apply firm pressure to the top of the deck board until the decking snaps into place over the retaining clips. Work along the row, snapping the deck board in place. Attach the remaining deck boards in place, snapping each onto a row of retaining clips.

Cut the overhanging ends of the decking boards flush with the outside joists, using a circular saw with a fresh carbide-tipped blade or a masonry cut-off disc.

Use 2" galvanized deck screws to attach the pre-fabricated facing, covering the exposed hollow ends and creating a decorative trim. Cover the screw heads with the screw caps.

Use a Template

Lay the decking boards so the ends overhang the rough opening. Make a cardboard template to draw a cutting line on the deck boards. (When framing for a tree, check with a tree nursery for adequate opening size to provide space for growth.) Cut the decking boards along the marked line, using a jigsaw. Unattached deckboards can also be cut to curved profiles with a jigsaw (inset).

How to Install Decking with Spiked Clips

Drive a spiked clip into the edge of wood decking at joist locations. Use the included fastening block to prevent damage to the spikes.

Drive a deck screw through the hole in the clip and down at an angle through the deck board and into the joist. One screw secures two deck boards at each joist location.

Set the adjacent deck board into place. Tap it against the clips to seat the spikes, using a scrap block and hand maul or sledge hammer.

How to Install Decking with Biscuit-style Clips

Cut a #20 biscuit slot into the edge of deck boards at each joist location using a biscuit joiner (plate joiner). Set the slot height so the bottom edge of the biscuit clip will touch the joist edge.

Insert the biscuit clip into the slot. Drive a deck screw through the hole in the clip and down at an angle through the deck board and into the joist. One screw secures two deck boards at this joist location.

Lay a bead of construction adhesive along the edge of the joist to keep it from squeaking later. Cut slots in the adjacent deck board and fit it over the clips of the previous board.

The Case for Hidden Fasteners

The hidden fastener options shown here are only a few of the excellent alternatives to conventional face-nailing or screwing methods. The biggest advantage is aesthetic: no screwheads or nail heads mar the surface of your deck. But there are other benefits to hidden fasteners as well. Face-screwed wood decking is more prone to rotting, because water can collect in the screw head pockets. If you nail the decking down, the nail heads are bound to eventually pop up as the decking dries, contracts, or moves under use and wear. Hidden fasteners eliminate both of these problems. If you use spike- or biscuit-style clip systems, be aware that you may need to remove large sections of deck boards in order to replace a damaged or defective board in the future, because the fasteners lock adjacent boards together and hide access to the fasteners. The same is true of many other hidden-fastener systems.

How to Install Decking with Undermount Deck Brackets

Install the deck brackets along the top edge of each joist, alternating brackets from one side of the joist to the other in a continuous series. Secure the brackets with screws driven into the side of the joist.

Secure the deck boards by driving screws up through the bracket holes and into the joists. Depending on space constraints, these screws can be driven from above if necessary.

Continue installing all of the deck boards from below. When you reach the last board, you may need to install it from above for access reasons. Drive deck screws through the deck board and into the joists below. To maintain the hidden fastener appearance, counterbore the pilot holes for the screws and fill the counterbore with a plug cut from a piece of scrap decking.

How to Install Decking with Biscuit-style Clips

Set a deck board into place on the joists, and slide a clip against it so the spacer tab touches the edge of the deck board. Drive a screw through the center hole of the clip and into the joist.

Drive a deck screw up through the plastic clip and into the deck board to secure it.

Position the next deck board against the clip’s spacer tab, and drive a deck screw up through the clip to fasten it in place. One clip secures two deck boards at each joist location.