- If you want to make a picnic table, you need treated wood, screws, carriage bolts and tools to cut and smooth the wood. For a large picnic table, gather 2x6s for the legs and 2x6s or 2x4s for the tabletop and seats. To cut the wood, you need a saw that can make angled cuts like a radial arm saw, compound miter saw, circular saw or handsaw and miter box. If you don't have any of these tools, you may be able to have your local home improvement store cut the wood for a small fee. You also need to have a power sander, drill, level and square.
- You can't just use any kind of screw or carriage bolt when you are working with treated wood. You need to use stainless steel or hot-dipped galvanized fasteners because they are resistant to the corrosive chemicals used to treat the wood. Stainless steel fasteners are the most resistant to corrosion, but they are more expensive. Hot-dipped galvanized fasteners are more affordable and have a thick coating of zinc to protect them from corrosion. Don't mix hot-dipped galvanized and stainless steel fasteners in the same connection.
- Keep comfort and usability in mind when you are designing and constructing a picnic table. If you are building a table for an adult, the tabletop should be 30 to 32 inches tall with the seats 16 to 18 inches aboveground. If the seats will be attached, make sure they are wide enough and far enough away from the table for an adult to sit down comfortably. You can make a smaller picnic table for a child, but leave some room so they don't outgrow it too soon. If you want to go beyond the basic rectangular table, you can try making a round, hexagonal or octagonal one.
- For a basic picnic table, cut four leg pieces, four tabletop supports and four seat supports to the desired dimensions. Miter-cut each end of the leg pieces in the same direction so the legs stand at an angle. Miter-cut the bottom corners of the tabletop and seat supports. Sand the rough edges and splinters off each board. Make an A-frame by attaching a tabletop support and a seat support to two leg pieces. Attach a second set of supports to the other side of the leg pieces. Make sure the tabletop supports are flush with the tops of the legs and all of the supports are level and centered. Add a carriage bolt at each joint for additional strength. Prop or have an assistant hold the legs up while you lay 2x6 or 2x4 boards across the top. Line up the edges of the boards and drive a screw through them into each of the four supports below. Add angled braces underneath the table if it shifts from side to side.
