How to Build a Circular Free-Standing Concrete Form

Create a circular concrete mold out of bender board.

Create a circular concrete form that's free-standing out of bender board. Bender board is flexible board that can be curved into shapes. Plywood or two-by-fours will typically break before you can obtain a full circular shape. Bender board is available at home improvement centers and many landscaping and garden centers. Create circular forms for patio walkways, stepping stones or decorative tabletops. When not making your circular concrete forms outside, make them on a heavy sheet of plywood and set aside while the concrete cures.

Things You'll Need

• Bender board
• Wood screws
• Drill
• Petroleum jelly
• Ratchet strap or bungee cords
• Marbles or river rock
• Plastic tarp

Instructions

1. Measure the area for your concrete and determine how large you need your circle to be. Bender board typically comes in 4-inch-wide planks that are 1/4-inch thick and 10 feet long. Cut the bender board to fit the circle you want to make.

2. Overlap the ends of your bender board slightly and screw them together using wood screws and a drill. Use three screws to secure your bender board together.

3. Set your circular form in place and secure it with a ratcheting strap. Wrap the strap around the outside of your form, hook the two ends together by sliding one hook on one end, through the hook on the other end, and ratchet it to remove the tension, tightening it so it's snug against your circular form. The strap provides the bracing for your concrete form, holding it in place and preventing bulges when its filled with wet concrete. You can also use several bungee cords for bracing.

4. Coat the inside of the circular form with petroleum jelly. Use only a thin coat of petroleum jelly to help release the concrete from the form when the concrete is fully cured.

5. Fill your form with concrete. Tap the sides of your form forcefully to remove any air bubbles. Decorate the top of your form with marbles or river rock pressed into the concrete so they're nearly level with the concrete. Cover the concrete with plastic for a week to keep the moisture in the concrete. Wait a month before removing the strap and the circular form.

Tips & Warnings

• Ratcheting straps are available at your local discount store. Choose ratcheting straps with hooks on both ends of the straps.

References

• Quikrete: Patios, Walkways and Stepping Stones: Using Molds
• The Mold Store: How to Make Custom Stone, Tile, Pavers and Bricks With Concrete and Molds