Saturday Morning Workshop: Outdoor Trestle Bench

Cut the cedar boards to length

Cut the cedar to the following pieces from 2×4 cedar:

• Seven 60-in. seat rails
• One 37-in. stretcher
• Two 9-in. crossbars
• Four 17-1/2 in. legs

Cut the 1×3 cedar to eight 3-1/2 in. pieces.

Cut the notches into the legs

Clamp a scrap piece of 1/2-in. plywood to the table saw fence and set the fence so that the leg board (B) is lined up with a 2-1/2 in. mark from one of the ends. Make sure that the temporary plywood fence is behind the blade. Set the blade to 3/4-in. high. Run the board through the table saw at even intervals and make sure to trim the very end, as it will make the next step easier. Clamp the board to the work surface and chisel out the leftover wood from the notch and sand to an even finish.

Drill holes for the threaded rod

Mark out the locations of the threaded rod holes on one of the seat rails (A). We are calling this the “pattern board”. Drill 1/2-in. holes into the pattern board with a sacrificial board beneath it. Clamp the pattern board and the other seat rails and drill two 1/2-in. diameter holes through the ganged boards to keep the holes consistent. Mark an “X” on the edge that you want to face up once assembled.

Create the spacer blocks and legs

Use the pattern board to drill into the legs. Then use the leg to drill the holes into the spacers.

Stain or seal all the boards

With all of the boards cut, brush on a waterproofing stain to seal the wood. Doing this step now will save a lot of time down the road because you won’t need to try to get the stain in tight corners once the bench is fully assembled. Let it dry completely.

Make the seat assembly

Fasten the 1/2-in. washers and 1/2-in. nuts onto one end of the two threaded rods. Alternatively slide the seat rails (A), spacer blocks (C) and legs (B) onto the two 1/2-in. threaded rods as shown. If they don’t go on nicely, swing a rubber mallet to knock the piece onto the threaded rods. Fasten the spacers level by firing 1-1/2 in. 18-gauge brad nails the spacers to the seat rails so they don’t rotate. Finish the assembly by attaching the washer and nut onto the threaded rod.

Cut the threaded rods

Use a reciprocating saw and a medal-cutting blade to cut off the excess threaded rod. File the jagged edges.

Fasten together the stretcher assembly

Layout the crossbars (E) and stretcher (D) on the workbench. Temporarily fasten the crossbars into the ends of the stretcher with a brad nail gun or glue. Drill 9/32-in. pilot holes for the 3/8-in. x 4 in. lag screws through the crossbars and into the stretchers. Then drill 3/8-in. clearance holes into the crossbars.

Connect the stretcher to the rest of the bench

Lay the bench assembly upside down on the workbench. Use scrap 2×4 boards to create a 5-in. gap between the seat rails (A) and crossbars (E) consistent. Clamp the crossbars to the to the bench assembly from the outsides of the legs, level the boards accordingly. Drill 9/32-in. pilot holes for the lag screws through the legs and into the crossbars. Then drill 3/8-in. clearance holes into the legs. Fasten the stretcher assembly to the bench with 3/8-in. x 4 in. lag screws.