DIY Outdoor Chair Building Guide: 3 Easy Steps

Today we are going to build an outdoor chair! I will also tell you how to easily adjust the measurements to change the size of the chair to turn it into a loveseat or couch.

Below, I have included a cut list and placement, please refer to these when I’m going over the how-to process! I based all my cuts off the 24” x 24” Hampton Bay cushions.

After building my chair, I drafted basic renderings and perfected my cuts and plans. You can either cut all the pieces in the beginning or go phase by phase. The choice is yours!

Next, let’s assemble the outer sides of the chair, grab your 3” and 4” star head screws, wood glue and impact driver. Lay out four of your 26” diagonal cuts in a square on a flat surface. Start with one corner and add wood glue to the end of the board. If you have big enough corner clamps, you can use them here, I did not, so I just used my body weight to hold the piece in place while I added two 3” screws and one 4” screw to each side of the corners. Repeat until all corners are attached and both squares are made.

This is your opportunity to adjust the measurements if you want a loveseat or couch instead of a chair, refer to the renderings and pick your 2” x 8” cut sizes.

Once all your 2” x 8”s are cut, grab your Pocket-Hole Jig, and place four pocket holes on each end of your boards. There is usually a nicer side of the wood; I choose the side that has more imperfections to face the back of the chair (less seen) and place the pocket holes.

At this point we are ready to sand, stain & seal the base. Before we sand, use wood filler and fill any cracks in the wood or any screws that are visible. Once the wood filler is dry, use your orbital sander and sanding discs, sand all sides and ends of your boards first with 80 grit, then 120, and lastly with 220.

After you finish sanding it’s time to stain. We will start with a wood conditioner as this gives the stain the best chance for an even application without splotches. Give the wood conditioner 30 minutes to soak in before staining. The actual stain color is up to you. I used one coat of Antique White for a whitewash to reduce the yellow from the wood, then two coats of my favorite stain, Early American. I used oil-based stains, which require 24 hours to dry before applying a water-based stain. After 24 hours, we can seal our boards. I applied three coats of the Spar Urethane, sanding with a 220-grit sanding block between each coat of sealer.

We are ready to assemble the base! Reference the renderings for proper placement of the boards and support pieces. Using spare 2” x 4” blocks, place them under the 2” x 8”s for the proper base height (view image). Attach the 2” x 8”s to the 4” x 4”s using 3” star head screws and 2.5” kreg pocket screws.

Before we move to the next phase, grab your caulk gun and 100% clear silicone caulk and caulk anywhere two pieces of wood meet each other to prevent any water from getting in and to extend the life of this sectional as long as possible!

When everything fits perfectly, evenly space out the 10” boards, roughly 3” apart. Use wood glue pocket screws and clamps to assemble the back, make sure the pocket holes are facing the backside, for a better aesthetic.

Now that the backs are built, go ahead and wood condition, stain and seal your built backs, your 2” x 2” and 1” x 4” the same way you did the base. I added silicone caulk to all the pocket holes to prevent any water damage in the future. You could use pocket hole plugs instead here, but silicone caulk is much more cost and time effective, and you’ll never be looking at the back if it’s against a wall. If your bench is sitting in the open, I would suggest using pocket hole plugs, then sanding and staining them to match.

Once your boards are sealed and dry, reference the second set of renderings I provided and cut all your slat support pieces and slats. Dry fit your pieces first and make any cut adjustments necessary. They should fit perfectly, but we are human and it’s best to double check!

Grab your 2” star head screws, countersink bit & impact driver. Pre-drill four countersink holes and screws into the slat supports. Use a slat to ensure the placement of the slat support is the perfect height for the slat to sit level with the base of the bench. Using a clamp to hold the slat support, grab your impact driver and screw in the slat supports.

Once the slat supports are installed, grab your silicone caulk and caulk all the seams as well as the screw holes.

Grab your slats, 18ga Brad Nailer and 1.5” brad nails. Evenly space them out across your chair and use three nails on each end of your slats. Again, grab your silicone caulk and caulk all the slat seams and nail holes.

Note: Using the silicone caulk is NOT necessary, but I believe it will extend the life of this outdoor chair.