How to Make a Concrete Fire Pit
Combine a metal bowl and a concrete base to create a stylish, modern fire pit.
We build a concrete form then filled it with gravel and a metal fire bowl to create this unique fire pit.
Before building a fire pit, explore local community ordinances regarding fire pits. Don’t forget to alert your insurance agent, too. In drier regions of the country, fire pits can impact insurance premiums. Choose your site carefully — keep flames at least 20 feet from surrounding structures or plants, including overhead trees.
1. Grade Area
Make sure you have a solid foundation. Add base rock or sand to make area level.
2. Build Concrete Exterior Form
Nail together four 4-foot lengths of 2x12 boards to make a square. Set on the graded area. Build a second square out of 2x6s cut at 4-foot lengths (Image 1). Set one square on top of the other and secure them with 2-1/2'-long forming stakes set on the outside of the form. Use two stakes per side (Image 2). These will also secure the form to the ground, keeping it from shifting. Make sure the square sits level.
3. Build Concrete Interior Form
Repeat same steps for the inside frame but make it 8 to 10 inches smaller. Attach the upper and lower frame squares using foot-long sections of 2x6 boards nailed to the inside of the frame. (Image 1) Set frame inside the exterior frame, making sure it sits even on each corner, creating a 4- to 5-inch gap (Image 2). Stake in place, installing the stakes on the inside of the frame. Make sure the entire frame is level.
4. Add Reinforcement
Hammer 20-inch pieces of rebar into the corners of the square as well as along every foot inside the frame (Image 1). Make sure the rebar is securely in the ground and sits below the edge of the frame.
Run 4-foot pieces of rebar horizontally between the vertical rebar. Tie these together with steel metal wire. This will make a grid (Image 2). Cut the wire with wire cutters.
5. Add Wire Mesh or Matting
For extra reinforcement, add wire mesh or matting. Cut these pieces to fit inside the form. Tie to the rebar grid with wire.
6. Pour Concrete
Pour concrete inside the frame (Image 1). Tamp down the concrete to removed air holes; you don't want any spaces inside the form. Smooth off the top with a trowel. Use a mallet to tap the forms while concrete is still wet — this releases the concrete from the forms while drying. Let dry for 24 hours (Image 2).
7. Strip Forms
Once the concrete is dry and set up, carefully remove the wood forms.
8. Add Finishing Touches to Concrete Frame
Add a thin layer of mortar along the outside of the frame to add a smooth finish (Image 1). If desired, cut pieces of slate to fit the top of the frame and mortar in place (Image 2).
9. Fill With Gravel
Add gravel about three quarters of the way full, so the top of the fire bowl will be flush with the top of the concrete frame.
10. Set Fire Bowl in Place
Add or subtract gravel accordingly to bring the fire bowl to the correct height.
11. Add Decorative Rock
Add large cobblestones, such as Mexican pebble, along the outsides of the bowl until only the top rim of the bowl is exposed. Add a little flagstone or slate to cap the concrete frame, and this fire feature is complete.