Build a picnic table with your kids in one weekend

A picnic table is the only project I know that a kid can help build on Saturday morning and eat lunch on by Sunday afternoon. That matters more than you think. Bookshelves go in a corner. Birdhouses get chewed by a squirrel. A picnic table sits in the yard where everybody walks past it, and your kid gets to say "I built that" roughly four thousand times before Labor Day.

The classic A-frame design hasn't changed in seventy years because it doesn't need to. Six feet long, about 30 inches to the top surface, 17 inches to the seat. Legs splayed at 30 degrees. Everything is 2x6 and 2x4, everything is straight cuts at two angles, and the whole thing holds together with deck screws and eight carriage bolts.

The cut list is shorter than you'd guess

For a 6-foot table in pressure-treated pine:

• Top: five 2x6 at 72 inches
• Seats: four 2x6 at 72 inches
• Legs: four 2x6 at roughly 36 inches, both ends cut at 30 degrees, parallel
• Top cleats: three 2x4 at 28 to 30 inches, ends trimmed at 30 degrees so they don't stick out past the top
• Seat supports: two 2x6 at 60 inches
• Diagonal braces: two 2x4 at about 44 inches, 30-degree cuts on each end

That's it. Cut one leg, get it perfect, then use it as the pattern for the other three instead of measuring four times. Same with the braces. The single fastest way to build a table that rocks is to measure each leg independently and end up with one of them a quarter inch short.

Price it at the yard before you commit. Treated pine is the cheap way and it's fine. Cedar looks better and costs a lot more, and it dents if somebody sets a cast iron skillet on it. Your call.

Let the kid pick the boards

This is the first real job, and it's a good one. At the lumber rack, show them how to lift a 2x6 off the pile, set one end on the concrete, and sight down the edge like a rifle barrel. Bows show up immediately. So do twists, which are the ones that'll ruin your afternoon.

Every board has a crown, a slight arch along the edge. Mark it with a pencil arrow. Crown goes up on the tabletop so water runs off instead of pooling. Kids love this part because it feels like a secret. It is, sort of. Half the guys in that aisle grab whatever's on top.

Treated lumber straight off the rack is often soaking wet and heavy. It'll shrink as it dries. If the boards feel damp, butt your top and seat boards tight together, because gaps will open on their own. If you bought kiln-dried treated stock, leave a quarter-inch gap and use a scrap of plywood as a spacer. Get this backwards and you end up with a top you can drop a hot dog through.

Who does what

Give real jobs, not pretend ones. Kids know the difference instantly.

Four to six: hold the dumb end of the tape. Carry boards with you, one on each end. Hand you screws one at a time out of a coffee can. Sand with a block after the cuts are made. Later, brush on finish with a chip brush and take the blame for exactly none of the drips.

Seven to nine: run the drill. Set the clutch low, start the screw for them, then let them drive it. They'll strip a few heads and drive a few crooked. Leave the crooked ones in. Mark layout lines with a speed square and a sharp pencil.

Ten to twelve: pilot holes, countersinks, driving the carriage bolts, tightening nuts with a wrench. Reading the tape and calling out numbers while you cut.

Thirteen and up: the saw, with you standing right there, every single cut, until you've watched enough of them to stop standing there.

Eye protection on everybody within ten feet, including the one who's just watching. That's not negotiable and it's the rule they'll carry into their own garage in twenty years. No loose sleeves, no hoodie strings, hair tied back. Say out loud where your hands are before each cut. Treated sawdust is nasty stuff, so wear a mask when you're cutting, wash hands before lunch, and don't ever burn the offcuts.

Assemble upside down, on the flattest ground you've got

Lay the five top boards face down on the driveway, crowns pointing at the concrete. Snug them up, then run the two outer cleats about 12 inches in from each end and the third dead center. Screw through the cleats into the top boards, two #9 x 2½-inch deck screws per board. Pilot everything within two inches of a board end or you'll split it and have to explain why you're saying nothing out loud.

Legs next. They lap onto the outer cleats, spread 30 degrees, bottoms landing about five feet apart. Clamp them, check that the same amount of leg sticks past the cleat on both sides, then drill through and set two 3/8-inch carriage bolts per leg, 4 inches long, washer and nut on the inside. Not screws. The leg-to-cleat joint carries every bit of the racking force when four cousins sit on one end, and screws will loosen and wallow out the hole in a season.

Seat supports go across the legs at 17 inches up from the bottom of the legs, measured with the table still upside down, which is confusing enough that you should draw it on a scrap. Two bolts per joint again. Then flip it, lay the seat boards on, and screw them down from the top.

The diagonal braces run from the center cleat down to the seat supports. They look optional. They're not. Skip them and the table walks across the patio every time somebody stands up.

The step everybody skips

Break every edge. All of them. A sanding block with 80-grit, three passes down each corner, especially the front edge of both seats and the perimeter of the top. It takes twenty minutes and it's the difference between a table your wife sits at in shorts and a table nobody touches.

This is the perfect job to hand a kid who's lost interest in the drill. Let them run their palm down an edge you've eased and then down one you haven't. They'll get it.

Wait on finish. Treated lumber needs weeks to dry before it'll take anything. Sprinkle water on the top, and if it beads instead of soaking in, it's not ready. When it is, use an oil-based penetrating deck stain, not paint. Paint on a horizontal surface in the sun peels within two years, and then you own a scraping project forever.

What'll go wrong

One leg will be a hair off and the table will rock. Find the high foot, mark it, take an eighth of an inch off with the saw. Somebody will drive a screw at an angle and blow the point out the side of a board. Back it out, move over an inch, keep going.

Before you flip it right side up for the last time, hand the kid a permanent marker and have them write their name and the date on the underside of the tabletop. Nobody will see it for thirty years.

Then somebody will.