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Building Better Decks, continued

Framing. Whenever decking boards deflect underfoot, a deck can seem unpleasantly flimsy. To ensure a solid feel, we usually frame our decks with 2x10 joists on 12-inch centers.

We typically run our decking diagonally. Trex is a dense, flexible material. Although you can special order it in virtually any length, it becomes impractical to handle in lengths over 20 feet. Butt joints in decking are ugly, so I purposely break the deck surface into pattern sections limited by the maximum plank length and separated by inlet strips -- full-width 2x6s that all the planks in an area die into (Figure 7).



Figure 7.Running the deck boards diagonally eliminates unsightly butt joints. The layout is planned so that no individual board will be longer than 20 feet (above). Joists are spaced on 1-foot centers to provide a stiff surface underfoot. Where adjacent diagonal runs meet, an inlet strip, fastened to blocking between joists (right), provides a pleasing transition.

A 2x10 finish band wraps the perimeter of the deck framing and conceals the joist end-nails.

Working with Trex. Because Trex doesn't have the warping tendency of solid lumber, heavy fastening isn't needed. Originally, our specs called for the decking to be screw-fastened on alternating sides of each board, one screw per joist, to minimize the pattern of the fasteners. But last year, the county stepped in and required double fastening at every joist, so that's now our standard method.

A Quik Drive screw gun automatically sets proprietary square-drive, ceramic-coated trim-head screws below the surface (Figure 8). This leaves a little eruption of material, or "mushrooming," around the hole. While one worker screws the decking, another follows behind and hammers the mushrooms flush, effectively concealing the screw heads. To create a more finished appearance, we also use a router to radius the edges of all butt joints and any place where the decking changes direction.



Figure 8.The decking is fastened with trim-head screws, which are buried slightly below the surface of the composite decking. Each screw creates a small "mushroom" that is hammered flat to conceal the screw head.

Solid wood decking. We offer solid-wood decking as a higher-priced (and more profitable) upgrade. On those jobs, we use ipe, a tropical hardwood, and fasten it with Eb-Ty concealed connectors (Eb-Ty, 888/438-3289, The Eb-Ty connector is an oval-shaped plastic wafer designed to fit in a standard biscuit slot cut into the edge of the plank. We save some serious time by ordering the 5/4x6 ipe planks premilled with a running groove on both edges, replacing the biscuit cutter entirely (Figure 9). But installing ipe still takes longer, because each connector must be individually screwed to the joist beneath.


Figure 9.Tropical hardwood decking is fastened with the Eb-Ty connector system, which uses a slot-mounted plastic biscuit. Rather than cutting individual slots with a biscuit jointer, the author increases productivity by ordering deck boards with premilled grooves.

Railing posts. We make most of our rail posts from 4x4 cedar, because pressure-treated posts tend to split and check as the lumber dries out. We occasionally use pressure-treated posts as a budget concession but only after warning the customer to expect those types of flaws. To locate the posts along the deck's perimeter, we divide each side of the deck into equal segments of 5 feet or less.

To make post installation as efficient as possible, we cut the 4x4s to a standard 45 1/2-inch length before squaring a line across each at the level of the deck surface. We then drive a hanger nail partway into the post, just above the line (Figure 10). This nail helps hold the post at the proper height while it's plumbed and temporarily toe-nailed in place. Once all the posts have been positioned in this way, each one is drilled for a pair of 1/2-inch carriage bolts spaced on either side of the centerline and as far apart vertically as the joist depth will allow.



Figure 10.A temporary "hanger nail" driven into a precut post at the level of the deck surface provides temporary support while the post is tack-nailed in place before bolting (top). To provide a simpler, stronger installation, posts are paired at either side of angle transitions and corners. The 4-inch gap between posts corresponds to the standard baluster spacing (bottom).

We place a full post at either side of every corner and transitional angle, leaving a gap between them approximately as wide as the maximum 4-inch gap between balusters. This is structurally stronger than relying on a single post, and it gives a distinctive and substantial look to the railing system.

Railing assembly. We like to limit railing sections to maximum 5-foot lengths. Longer segments allow too much lateral deflection under loading and may also require awkward-looking intermediate support between deck and subrail to prevent sagging. After bolting the posts in place, we measure between sections and assemble a section of railing to fit. Our most popular railing systems include a top and bottom railing separated by the balusters.

Kids like to climb up on the horizontal subrail of a baluster railing to peer over the top. But all that hopping up and down soon separates the subrail from the balusters. To counteract that, we screw the center and end balusters through the top and bottom rails. That's much more effective than hoping kids won't be kids. The remaining balusters are secured with finish nails, which leave smaller, easily filled holes.

We always fill all fastener holes and sand and stain the railing systems. If the customer elects to use pressure-treated railing components, I recommend a darker finish color to better conceal the inevitable cracks and checks in the lumber. Lighter colors only highlight the defects.

Jim Craig

is the owner of Craig Sundecks & Porches, in Manassas, Va.