Things You'll Need

Instructions

1

Determine the diameter and thickness of the fire pit ring with a measuring tape. The ring should be at least 5 inches thick for optimal stability and safety.
2

Cut a section of bender board to the outer circumference of the fire pit ring, plus an additional 4 inches, with a jigsaw. You can determine the outer circumference by multiplying half the diameter by 3.1416, then multiplying the result by itself. Cut an additional section of bender board to the inner circumference of the ring, plus an additional 4 inches, using the inner diameter to calculate the circumference.
3

Bend the outer and inner bender board sections into circles, and overlap the ends by 4 inches. Drive nails through the overlapped sections of the bender board, using a hammer, to secure the forms.
4

Center the inner form inside of the outer form in the desired location of the fire pit. Drive wood stakes into the ground with a hammer along the outside of the outer form, and along the inside of the inner form. The stakes hold the two circles of bender board in place when you pour concrete in the space between them.