Picnic table on a pedestal
If you're looking for a more refined picnic table, one that will fit right in at a dinner party for adults as well as at an afternoon barbecue with the kids, here's the design for you.
Its pedestal support ensures that no one can complain about “having the leg.” The round top is made from 1-in. thick “five-quarter” deck boards (abbreviated as “5/4”). This means it has a stronger top than one made of 1x6s, and a less chunky look than one made of 2x6s. Unlike many other tables, this one has no screws or nails visible on the top.
You'll appreciate the strong and simple way this table is assembled. Rather than using elaborate dowel or mortise-and-tenon joints to hold the base together, we've used a long threaded rod that goes right through the pedestal legs from top to bottom (Fig. A). It gives enormous strength and rigidity to the table. The only drawback is that you need to buy an extra-long bit to drill the hole. The 48-in. dia. top will easily seat six or seven people.
Figure A: A Pedestal Picnic Table
This expanded diagram shows the construction of the picnic table. For a larger version and for the Cutting List and Shopping List see Additional Information, below.
What it takes to build
Although this project isn't difficult, it is more complicated than the typical A-frame picnic table. You need a jigsaw to cut out the round top, and you have to be a bit more precise with your circular saw. A power sander will help you clean up the edges. You'll need a hacksaw to cut the threaded rod to length, a socket wrench to tighten the nuts, and a couple of 14-in. capacity clamps. To drill the long holes for the threaded rod, you need to buy a 16-in. long (or longer) x 1/2-in. dia. bit (Photo 3). This type of bit is called a “bellhanger” or “installer” bit, and is available at home centers.
We used clear, vertical-grain rot-resistant wood for our table just because of its wonderful appearance. If you make the table from construction-grade cedar or redwood, the cost will much less. You can use pressure-treated wood for the base, but we recommend that you stay with redwood or cedar or other naturally rot-resistant wood for the top to avoid potential food contamination. If you choose pressure-treated wood for your table, be sure to use plates and cutting boards so that food doesn't come into direct contact with the wood.
- Cut the four parts that form the X-shaped feet and top support (parts A, B and C) to the lengths given in the Cutting List. A blade designed for trim work will give you the smoothest cuts. Draw a line across each board in the middle.
- Lay the four boards on a pair of sawhorses and clamp them edge to edge so the lines you drew earlier all line up. Draw where the half-lap cutout (see Fig. A) will be across all four boards. This cutout is what allows the boards to overlap to make an “X.”
- Adjust your circular saw (use scraps for testing) so it cuts exactly half the thickness of your boards, then saw a series of cuts to remove the wood in the half-lap cutouts (Photo 1). You can use a square to guide the saw on the outside edges of the cutout for more accuracy. (You can also make this cut with a router and dado bit, or a table saw equipped with a dado blade.) Use a piece of scrap 2x4 to check that the cutout is wide enough before you remove the clamps. Clean up the cutout with a chisel or rasp.
- Now get ready to cut the beveled ends on the four boards (Photo 2). Because each half-lap joint is assembled with one piece upside down, you need to flip either part A or part B over (not both), and flip over one part C, before you can cut the beveled ends. Line up the ends of the boards, clamp them together, and cut the angled ends (Photo 2). It works better if you mark your cutting line on the ends of the boards so that when you cut, the wide part of the saw base is supported by the boards. (You can also use a miter saw for the bevel cuts.) After the cut, flip the boards over and sand all the cut surfaces at once. Then remove the clamps and repeat the process at the other end.
- Mark and drill the 1-in. holes in parts A, B and C (see Fig. A). Be sure that you drill them on the sides of the boards that don't have the beveled cuts. Then drill the 5/16-in. holes.
- Cut the four pieces of 4x4 that make the pedestal legs (part D). If you're cutting them with a circular saw, mark a line on all four sides and then cut from opposite sides. It's more important to have the ends flat and square, and all four pieces the same length, than to make them exactly the length given in the Cutting List. So if you need to trim them a bit, go ahead.
- Drill a 1/2-in. hole through the center of each pedestal leg, going in halfway from each end (Photo 3). Sight carefully to be sure the bit is going in parallel to the leg. By the way, don't try to substitute a spade bit in an extension—it'll cut so badly that it'll burn out both your arms and your drill.
- Sand all the parts you've worked on so far. Screw a nut onto the threaded rod, then cut your threaded rod to length with a hacksaw. File the cut end smooth and screw the nut off the cut end to machine the threads. Assemble the two base pieces (C) to make an “X,” and support it on sawhorses or blocks. Stand the 4x4 legs on the base, put pieces A and B on top of them, and fit the threaded rods to hold the unit together (Photo 4). Tighten the nuts from both ends. Screw on the feet (E). Fill the holes where the nuts are with brown caulk.
- Begin making the top by cutting the boards F, G and H to the lengths given in the Cutting List. Cut the longest pieces (H) first, then cut parts F and G. Draw a line across the back of each board in the middle. Then assemble a clamping jig out of 1x8, as shown in Photo 5. Lay the boards on it upside down, with their center lines aligned and 1/8-in. cardboard spacers between them (Photo 5). Tighten the wedges on the jig just enough to hold the boards in position.
- Put a nail in the middle of the middle board, and draw a circle on the boards (Photo 6). Use a wire for a compass. Take the boards out of the jig, cut out the arcs with a jigsaw, and reassemble the top on the clamping jig, including the spacers. You will need to reposition a wedge block.
- Set the upside-down pedestal assembly onto the boards (Photo 7) and screw it down. Cut the cleat boards (J and K), and screw them down as well. Flip the table over, remove the spacers, and sand the top. Apply an exterior finish, and you're done.
Figure B: Tabletop Supports and Crosspieces
The boards that form the tabletop are aligned and held together with hidden crosspieces screwed to the underside.