Imagine a deck builder who met his untimely death in 1982. If you could bring him back to life in 2012 and plop him down on a brand-new deck, he’d see much he didn’t recognize: curved composite decking with a matching synthetic railing system, LED lighting, a hot tub, a gas fire pit. The greatest shock, though, might come when he walked under the deck and saw the number and variety of metal connectors that were holding the whole thing together.
He may have seen joist hangers and carriage or lag bolts before, but all the other structural hardware would astound him. Starting at the ground, he’d see footing-to-post connectors, then more hardware at the top of the posts where they were bolted onto a beam. He’d marvel at the brackets that secured the rail posts to the joists. And when he got near the building and saw the galvanized bolts and brackets that secured the ledger to the house, he might just scratch his head.
“What’s with all this metal?” he might ask. “We used to toenail everything and it worked fine. But you know, the last thing I remember is we’d finished a big second-floor deck on a house on the side of a hill, and the homeowners invited us to a party on it. They had speakers out there, and a bunch of us were kicking it to Donna Summer’s latest record. I saw some guys wheeling out a few more kegs, and then the whole deck just started to go …”
Structural hardware is designed — and its use is required by building codes — to keep decks and their occupants safe. Codes are catching up with the fact that the structure of decks differs from that of houses. Not only are a deck’s framing and hardware exposed to the degrading effects of constant weathering — something the protected interior framing of a house is never subjected to — but add wind uplift and the way we attach decks to houses, and it’s no wonder that today’s decks are strapped, bolted, and tied down at a majority of connection points. And changes to the 2012 code make it even more necessary for a deck builder to know his metal.
Post to Foundation
The two big players in the structural hardware field, Simpson Strong-Tie and USP Structural Connectors, both make a wide variety of post anchors, some designed to be installed in wet concrete and others that are attached to cured concrete with anchor bolts and adhesives.
Many post-base connectors are adjustable to allow for fine-tuning the location of the hardware on the footing — a plus for plumbing up posts, particularly if a footing isn’t in the perfect location. Look for slotted bolt holes in the bottom plate of the connector, which give you varying amounts of wiggle room.
Height-adjustable post bases let you raise a post as much as 4 inches — handy if a footing settles or you want to adjust the pitch of a deck. USP’s version (APB44 for 4x4 posts and APB66 for 6x6 posts) costs about $7 and utilizes a threaded tube that is adhered or cast into concrete. A U-shaped bracket with a threaded rod gets fastened to the post bottom, allowing the post to be raised or lowered by turning the threaded rod into the tube. Simpson’s version for a 4x4 post, EPB44T (no offering for a 6x6), costs about $14 and uses a threaded rod adhered to or cast into concrete. After drilling a hole in the center of the post’s end grain, you fasten a U-shaped bracket with a nut to the bottom. To adjust the height, rotate the post and the threaded rod advances into the post’s hole.
Joist hangers are for the most part old news, but there are a few innovative ones that will help you out with nonstandard framing situations. For the end joists, it’s been common practice to use a standard flanged hanger and then hammer the flange over onto the edge of the perpendicular framing member, typically the deck’s ledger. Aside from the sloppy appearance this results in, especially on an overhead structure that’s visible from below, there’s a risk the galvanizing may flake off when the metal bends, not to mention that the hanger’s warranty will be void (Simpson and USP state in their literature that modifications to their products void the warranty). Flanged hangers might also get in the way, depending on the location and layout of other framing hardware.
Concealed-flange hangers solve all those problems. Their flanges bend inward toward the center of the hanger, giving the installation a clean, neat look. Unlike regular hangers — which you might fasten after installing the joists — you install concealed-flange hangers first, because the fasteners will be covered by the end of the joist. Note that the length of the joists will need to be 1/4 inch shorter due to the protruding fastener heads.
Skewed hangers come in lefts and rights and allow you to run joists at angles other than 90 degrees to the adjoining framing. Simpson and USP make hangers for joists that intersect at 45 degrees, but even more useful might be the field-adjustable skewed hangers that allow you to hang joists at any angle by bending the flange wings. To prevent metal fatigue, Simpson cautions, “Bend one time only.” Skewed and adjustable-angle joist hangers cost between $6 and $10 each, depending on joist size.