Shiplap for Woodworkers

Forget the flipping home-reno shows, shiplap also makes great cabinet backs.

Popularized by home-renovation TV shows, shiplap is enjoying a renaissance as a wall covering, but has always been a sound choice for door panels or backs for cabinets and bookcases. You can easily make your own with any of the three methods shown here, and even dress up the joint with routed profiles.

So, what is shiplap?

Although we could find no credible sources tracing its origin to actual ships, shiplap joinery has commonly been used to create a weather-resistant wallcovering. When shiplap boards are nailed in place rather than glued, the overlapping rabbets maintain lapped coverage as the boards shrink and swell because of seasonal humidity changes.

Your board width dictates the dimensions of the mating rabbets: For workpieces 4" or narrower, a 1⁄2" rabbet suffices; for boards between 4–8" wide, make the rabbet 3⁄4" wide.

Begin by jointing and planing all stock and a few test pieces flat, square, and to consistent thickness. Then rip the pieces to final width on the tablesaw. You can crosscut to final length now or after milling the shiplap edges. Determine the good/front face of each board and mark it. Then, cut the joinery using one of the following methods.

Lapping at the tablesaw

Install on your saw a stacked-dado set a little wider than your planned rabbet so you can cut each rabbet in one pass. To prevent cutting into your saw’s rip fence, attach an auxiliary fence, positioned slightly over the stack. Raise the spinning stack until you reach the desired height. Make test cuts in the extra pieces you prepared. If your saw or dado set won’t allow for a wide-enough stack, simply cut the rabbet in two passes.

Rabbet with a router

Although you can rout a rabbet with a straight bit and edge guide, a dedicated rabbeting bit makes the task virtually foolproof. Set the rabbet width by installing the appropriate guide bearing for the width of the desired rabbet. Installing an offset base on your router helps prevent the router from tipping and creating uneven cuts. After getting a perfect fit on your test pieces, rout all rabbets on the keeper boards.

Take it to the router table

You can also use a rabbeting bit on a router table—just make sure the fence faces align flush with the bearing. But with the fence as a guide, you can use any straight or spiral bit; we prefer downcut spiral bits on the router table for the cleanest cuts.

Use featherboards as shown below to ensure consistent rabbets. For rabbets wider than your bit’s diameter, rout the rabbet in two passes, moving the fence away from the bit after routing the first pass on all pieces.

Shipshape: Dress it up with details

With the edges rabbeted, your shiplap is ready for installation, but adding a routed profile kicks up the visual interest.

Tips for installing shiplap

Secure shiplap with brads or finish nails—no glue. Brads or nails will flex slightly, enough to allow for the expansion and contraction of each board.

Tip! When installing shiplap horizontally on a wall, use coins to set a consistent gap that allows for seasonal expansion and contraction. Nail into studs through the lapped joint, using a 15- or 16-gauge finish nail. If you’d prefer to avoid exposed nails, you can either set them and fill the nail holes before painting or finishing, or use construction adhesive on the lap joint and nail only the top (hidden) tongue.

We like MicroJig’s MatchFit clamps to secure an auxiliary fence. woodmagazine.com/ matchfit gap Cut the rabbets slightly deeper than half the board thickness, leaving a this is not a glue joint, you don’t need a tight fit. Run the board tight against the auxiliary fence Auxiliary fence and flat against the tablesaw top. 1⁄32" gap between them. Because For the second cut, flip the board with the first rabbet facing upward. 1 ⁄32"

A rabbeting bit with a bearing set lets one bit cut rabbets of various widths by swapping bearings. woodmagazine.com/ rabbetingbit Straight bit With featherboards pressing the workpiece against the table, rabbet, keeping the stock tight against the fence. rout the first Offset base Rout the rabbet in one pass to ensure identical cuts in all workpieces. Flip the board and rabbet the other edge. Flip the board and rout the opposing rabbet on the other edge.

Produced by Dave Fish Bob Hunter with Break up the plain look of wide boards by centering a V-groove on the front face with a V-grooving bit. No rabbet on this edge. When enclosing the back of a bookcase or cabinet, rabbet only one edge of the first and last pieces, so they fit gap-free in the rabbet along the case’s side. Add a half-bead profile with a beading bit. You’ll need a tongue at least a thick to do this. 3⁄8" Insert coins in the gaps between each piece. Use pennies or dimes for shiplap less than 4" wide; for wider pieces, use nickels or quarters. Buy these bits for your shop: woodmagazine.com/vgroovebit woodmagazine.com/beadingbit woodmagazine.com/45chamferbit Bevel the overlapping tongue’s edge with a 45° chamfer bit. This draws more attention to the joints. When installing shiplap vertically, such as this wainscoting, nail it at the top and bottom, where trim boards will cover the nails. Underlay 1⁄2" or thicker plywood or oriented-strand board (OSB) on the wall first because you won’t be able to nail into a stud with each piece of shiplap.