How to make a picnic table that converts to benches

About a month ago I was asked by the kids’ school to make some seating that could also double as desk space to use as an outdoor classroom. This was all part of a bigger project to build a pavilion in memory of a parent from a family in the school that passed away a short time ago. I found these convertible bench plans from Ana White, but modified them slightly to fit the purposes for our school. Instead of four feet long, I made these benches 6 feet long, added some extra bracing, and some hardware to make them suitable for wear and tear from lots of kids. Here is how to make a picnic table that converts to a bench, but also a desk!

Materials, Tools and Supplies

I made a total of 6 benches. If you want to make a single picnic table (or two benches), this is what you’ll need:

7 – 2″ by 6″ by 12′ pressure treated wood
4 – 2″ by 4″ by 8′ pressure treated wood (you will need more if you add the optional bracing)
2 1/5″ exterior galvanized screws
Drill
Speed square
Tape measure
wood glue or PL premium
orbital sander and paper

2. Cut your material

Now if you are going to build these benches, I would recommend you read over my article to see how you can modify these benches, but then head over to Ana White’s page too. She has great images and detailed instructions. I used her plan, but modified it slightly to work with what I needed for my project. This is the cut list that I used to make 6 foot long picnic tables:

Back legs – 4 of 2″ by 4″ by 28 7/8″ (ends cuts at 10 degrees parallel to each other)
Seat support – 4 of 2″ by 4″ by 27″ (ends cut at 10 degrees not parallel, measurement along the short end)
Front legs – 4 of 2″ by 4″ by 16 1/4″ (ends cut at 10 degrees parallel)
Seat and tabletop – 12 of 2″ 6″ by 72″ (ends cut square)
Table supports – 2″ by 6″ by 17″ (ends cut at 10 degrees not parallel, measurement from the long ends)

2. Build the leg pieces

Start building the leg pieces by using a 1/2″ drill bit, and drilling a hole 1 3/4″ from the end and centerd in the top. Do this for all four leg pieces.

Using your smaller front leg piece, draw a line on the longer back leg piece where the front leg lines up. This will make it easier to make the bench support straight. Lay the seat support on top of the front leg and back leg. You can add some wood glue before you screw them together. I decided to use PL premium since it’s stronger and is meant for outside. Pre-drill some holes, and then screw the legs together using 2 1/5″ galvanized screws. Make four of these leg pieces, making sure two of them are the opposite direction.

I made a total of 12 bench legs for the six benches.

3. Add the bench tops

Glue, pre-drill and screw the six foot long bench tops to the bench supports. Use a scrap piece of wood or a spacer to make a 1/4″ space between the boards. Also make sure that the bench seat boards are square to the bench supports. I decided to do a 12″ overhang on each side of the benches. This was to make sure that kids could sit on the end without the supports getting in the way of their legs. You can adjust this overhang as you see fit.

4. Make the picnic table top / bench back

Next take your 17″ tabletop support piece and drill a 1/2″ hold in the center. Line up your three tabletop pieces, just like you did for the benches. Add the same amount of overhang on each end as you did for the bench. Glue, pre-dill, and screw the tabletop to the supports, making sure that it is square and the boards are spaced 1/4″ apart.

5. Add extra bracing to the picnic table (optional)

I didn’t want the table tops to warp too much, so we ripped some fences boards in half and I glued and screwed a piece to each end of the table tops and bench seats. I also added an extra 2″ by 4″ piece about 4 inches under the bench piece, and screwed a cross brace into the bottom of the bench. These steps aren’t necessary, but if you feel like there’s some wiggle when you make a picnic table, just add some bracing.

6. Attach the bench back to the seat

Put the table top on the back legs and line up the two holes. Attach the pieces together using 4″ long 1/2″ diameter carriage bolts. Add a washer in between the two wood pieces, then a washer, lock washer, and nut to keep everything in place.

With the tabletop level with the bench, drill a hole through both the table support and the leg piece. This will be for the pin that will hold the table in the upright position.

Fold it down into the bench position, and when you feel like it’s at a comfortable angle, drill another hole to keep the bench in place in the bench position.

7. Sand the edges and rough patches

Using an orbital sander and a 60 or 80 grit paper, break the edges and corners and give the entire bench a light sand.

8. Add the remaining haRdware

I used an aluminum rod for the pins to keep the benches in position. We drilled a hole in one end and added a small cable so the pins wouldn’t get lost. I also added toggle clamp clips to the underside of the tabletops to clip the benches together when they are used as picnic tables.

I was told these benches have already been well used by the kids at the school. This is a great way to have an outdoor classroom and for the kids to spend more time outside during the day. Especially at this time, when the kids need a break from wearing their masks. The pavilion is not quite finished, but it’s finished enough at this point that it’s been getting some use for shade and in rainy weather!