In today’s hectic world, it’s nice to have a quiet place to relax, kick back and forget your troubles. This comfortable garden bench, when situated in quiet corner of your garden or yard, can be just the ticket to a calm state of mind. Created with the Zen principles of simplicity, austerity and subtlety in mind, this design combines wood and concrete for a striking look yet boasts a comfortable and calming feel.
If you’ve never thought of incorporating concrete into your outdoor furniture designs, you may be surprised at how easy it is to work with. Each pier for this bench is cast from a simple mold constructed from ¾-in. melamine. The wood seat is crafted from 4x6 cedar timbers and short lengths of 2x4s. And thanks to basic yet durable assembly techniques, the bench is sure to be an eye-catching addition to your yard or garden for years to come.
Download the plans: Click here to download this complete article as a pdf.
Building the bench base piers forms
Assemble the pier-form parts from ¾-in.-thick melamine, rigid foam insulation and PVC pipe as shown in the construction drawing (link to full article and drawing) and assemble them using silicone caulk and 1-1/2-in. drywall screws. Use silicone caulk to seal all of the seams and to adhere the foam spacers to the inside of the form walls.
Casting the piers
Once the silicone caulk has cured, you’re ready to mix and pour the concrete. Follow the instructions on the concrete bag – I used Quikrete 5000 high-strength concrete mix – to ensure that you use the proper amount of water, and add any color powder that you desire at this time. For our project, I used Fu Tung Cheng’s NeoMix Pigment in Olive.
Carefully pour the concrete into the mold. Work slowly so that you do not dislodge any of the spacers or the PVC pipe. As you’re pouring, occasionally stop and use a rubber mallet to gently rap on the sides of the forms. This ensures that the concrete settles to the bottom.
Once you’ve filled the form, take a stick and repeatedly poke it into the wet concrete, working it from top to bottom to eliminate any trapped air bubbles. Allow the concrete to cure for a few days before removing the mold. (It takes 28 days for the Quikrete to achieve 5,000 psi.) Then cover the area where the cedar beams will rest with a protective rot-resistant film such as self-adhesive windowsill flashing tape.
Building the seat
Start making the seat by cutting the 4x6 cedar beams to length. The easiest way is with a sliding compound miter saw, but a decent handsaw will work just as well, provided you take your time with the cut and keep an eye out for blade deflection.
To create the seat’s infield, begin by cutting 20 9-in. lengths of pressure-treated 2x4s. Build a drilling jig from scraps of 2x4 to ensure consistent placement of the holes for the two 34-in.-long x 3/8-in.-dia. threaded rods that will hold the infield slats together. To use the jig, simply clamp a 2x4 infield section into it and drill the two necessary holes. Note that you will need to counterbore the outside faces of the slats on each end of the infield to accept the washers and nuts that secure the threaded rod.
Assemble the infield by first attaching a nut and washer to one end of each of the two threaded rods. Slide one of the counterbored slats onto the threaded rods; then slide four washers (two per rod) down the rods and against the slat. Repeat the process – one slat followed by two washers per rod – until all 20 of the slats are in place. Check that the assembly is square, attach a final washer and nut to each of the rods and tighten the entire assembly.
Cut two 35-1/4-in. lengths of ¾-in. aluminum angle iron as shown in the drawing. Mark the center of the cedar beams and of the aluminum angle iron lengths. Drill five countersunk mounting holes through each of the aluminum brackets; then attach the brackets to the beams using 2-in. stainless steel deck screws.
To mark the location of the holes for the 15-1/4-in. x 3/8-in.-dia. threaded rods that will attach the cedar beams to the concrete piers, first clamp one of the cedar beams to the piers. Place a dollop of something soft, bright and gooey (such as lipstick – just don’t let your wife catch you) on the end of a long section of threaded rod; then slide the rod through one of the holes and press it firmly against the cedar beam so that it leaves a mark (photo 9, p. xx). Repeat the process for the other three holes.
Remove the beam from the pier and, using a drill guide, bore the four ½-in.-dia. holes at the locations you just marked. Note that you will need to counterbore the holes on the outer faces of the beams to a diameter of 1 in. and a depth of 2-1/2 in. To mark the hole locations on the second beam, first position both beams on the piers. Clamp them in place and repeat the process with the lipstick and the threaded rods; then drill the holes as you did for the first beam.
Final assembly
Move the piers, beams and seat assembly to the bench’s permanent location. Make sure that the piers are level; then loosely bolt the cedar beams to the piers. Run a heavy bead of outdoor-rated construction adhesive along both of the aluminum brackets and then drop the seat assembly in place. Tighten the nuts on the assembly rods until all of the parts are snug.
Plug the bolt holes with 1-in.-dia. hardwood dowels that have been stained to match the seat slats and contrast with the cedar beams. Allow the construction adhesive to cure; then apply a final clear protective finish to the wood and a clear sealer to the concrete. Once the finish is dry, your bench is ready to enjoy.