DIY simple four board outdoor bench plans

Here are a set of free DIY outdoor bench plans that only use four boards, and require limited tools.  This outdoor bench works well by the firepit, or by the garden. If pressure treated wood is used it should last years with minimal care. If you prefer to use untreated lumber a coat of paint or stain every few years will help preserve it.  These outdoor bench plans are incredibly easy, so they make a great project for even a beginner.  The whole project should only take about two hours.

Materials

  • 4 – 2″ x 8″ x 8′ boards (can be pressure treated, or untreated)
  • exterior wood glue
  • sander and/or sandpaper
  • 2 1/2″ exterior wood screws
  • stain or paint as desired

Tools

four board outdoor bench - dimensions

Step 1: Cut all of the pieces

There are only 10 total cuts to make in building this piece, with all of them being pretty straightforward.  Start by cutting two of your 2x8s in half, ending in the four 48″ long pieces. These will be the seat and back of your bench. Next use your speed square to mark three 30° lines, 38″ apart on the third 2×8. Cut along the lines and you now have the pieces for the long legs. We’ll come back and make the remaining cuts for these legs in the next step of these outdoor bench plans.

With the last 2×8, you’re going to mark another three angled lines, however pay close attention here. The first line is going to be 40°, the second line will be 45°, and the last one will be 40° again. Just as important, only one edge of each of these short legs will be 19″. Reference the diagram, and double-check your layout before cutting. These slight differences in cuts will mean that your seat winds up with a comfortable backward lean instead of being parallel to the ground. it is just a slightly more relaxed sitting position.

four board outdoor bench - cut diagram

Step 2: Cut the excess from the back of the long legs

This step is really optional, but I think it gives the bench a more finished design look. It also helps line up the backrest boards later on in the build. Follow the layout in the diagram below, mark your line and cut.

four board outdoor bench - long leg cutout

Step 3: Assemble the legs

Now that you’ve prepped all of your pieces, it’s time to start putting this bench together.  You are going to use four 2 1/2″ exterior wood screws for each side of the leg assembly. Since you’re going to want these legs to sit flat, I like to assemble the legs with them standing up. This is where the quick-grip bar clamps come in handy to hold the two pieces tight together while ensuring they are lined up correctly. I also like to stand them up next to a ruler laying on the work surface so it is easy to ensure I have the proper 6″ gap between their inside edges.

Before you screw the pieces together, double check two things. First, check to make certain the 19″ long side of the short leg is in the back. Second, make certain you screw the short leg on the inside of the long leg. This means it will be on the right side on one piece, and the left side on the other.

four board outdoor bench - leg assembly

Step 4: Attach the seat boards

Now that the legs of your outdoor bench are assembled it is time to attach the seat boards. Attach the front board first, using three 2 1/2″ exterior wood screws per end. Make certain to have the front edge of this first board overhang the fronts of the short legs by about 1 1/2″. Then leave a gap about 1/4″ – 1/2″ an inch and attach the second seat board, again using 3 screws per end.

four board outdoor bench - seat

Step 5: Attach the backrest boards

Your new outdoor bench is almost ready to use! This last step of assembly is attaching those backrest boards. You’re going to use three 2 1/2″ wood screws on each end of both boards. Start with the top board, aligning it’s top edge to the top of the long legs, and the back to the back of the long legs (this is where that extra cut in Step 2 comes in handy for alignment). Then leave a 1/4″ – 1/2″ gap and attach the second backrest board beneath the first.

TIP: To make holding this board in place a little easier, clamp one quick-grip bar clamp onto each long leg under where the bottom of the backrest board ends. This gives you a place to rest the board so you’re not trying to hold it up and align it to the back and screw it in all at once.

four board outdoor bench - backrest

Step 8: Sand and finish

Now that the assembly is complete, it’s time to give this outdoor bench a quick sanding. You don’t want people getting splinters! If you used non-treated lumber, take the time to add a coat of paint or outdoor stain to help it stand up to the elements. Then sit back and enjoy your handiwork!

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