- 1). Select the location for your pit barbecue grill. Drive a metal stake into the ground to mark the desired center of the grill. Choose a flat open area with enough space to place some chairs or a picnic table near the grill. The pit itself will be about 5 feet in diameter.
- 2). Tie a 2.5-foot string to the metal pole. Pinch it between your fingers and walk in a circle around the pole. As you move, use a can of spray paint or sprinkle chalk dust in the shape of a circle using the end of the string as your guide. Measure 14 inches in from the circle and mark a second circle. This will be the interior of your barbecue pit.
- 3). Dig out the ground between the two circles to a depth of 8 inches. Fill the trench with concrete. Smooth the concrete with a trowel and allow it to set completely. As the concrete sets, gather the stones and fire bricks you plan to use to build the walls of the pit and mix up a batch of mortar.
- 4). Spread a layer of mortar on top of the concrete base. Arrange a perimeter of stones inside the outer border. Don't place stones of equal size next to each other. Instead try to create a more natural feel by using stones of varying lengths and widths. Press each stone into the mortar. Fill in the gaps between stones with mortar using your trowel.
- 5). Build up the perimeter of your fire pit. Spread a layer of mortar on top of the first layer of stones and pile more stones on top. Continue to add layers of stone and mortar until the perimeter reaches a height roughly equivalent to the length of your fire bricks. Fire bricks are typically longer and wider than normal bricks and are designed to be heat resistant.
- 6). Spread a layer of mortar on the back side of the stone perimeter. Create the interior border of your fire pit by lining the fire bricks upright against the back side of the perimeter stones. Press the back of each brick into the mortar. Leave a 1/2-inch gap between the upright bricks. Fill the gap between the bricks with mortar and check that the bricks are all the same approximate height as you work your way around the circle.
- 7). Create supports for your grill using extra fire bricks. Imagining the circular fire pit as a clock face, mortar an extra fire brick upright in front of the bricks installed at 12, 3, 6 and 9 o'clock. The extra bricks should extend toward the center of the fire pit and provide a surface to rest the corners of the grill grate.
- 8). Apply a layer of mortar to the top of the barbecue pit. Cover the tops of both the stone and the fire bricks. Lay your capstones, which are stones that are mostly flat on top and bottom, in the mortar.
Arrange the stones all the way around the pit. Leave about 1/2-inch space between each stone but don't obstruct the grill supports. - 9). Fill in the gaps between the capstones with mortar. Use a stiff brush to remove any excess mortar from the surface of the BBQ pit. Allow the mortar to set completely before using your pit grill.
- 10
Arrange kindling and small pieces of wood in the center of the pit and light a fire. Place the grill grate on top of the grill supports. Allow it to heat for 15 minutes or more before you begin to grill.
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