How to Build an In-Ground Fire Pit
Construct a durable, safe in-ground fire pit using retaining wall blocks, a compacted gravel drainage base, and perfectly leveled stone courses.
- Read the tools, materials, safety notes, and steps below for free.
- Tap Start Camera Coach when you want hands-free voice help.
- Allow camera and microphone. Point your phone at the work; the coach watches your progress and tells you the next step.
🧰 Required Tools & Equipment
- ✓ Shovel
- ✓ Hand tamper
- ✓ 2-foot bubble level
- ✓ Rubber mallet
- ✓ Tape measure
- ✓ Marking paint
📦 Materials & Supplies
- ✓ Curved retaining wall blocks
- ✓ Crushed stone paver base
- ✓ Lava rocks or drainage gravel
- ✓ Landscape fabric
⚠️ Safety Checkpoints & Warnings
- • Call 811 to locate underground utility lines before digging any depth into the yard.
- • Verify the pit location is at least 15 to 20 feet away from houses, fences, low-hanging branches, and dry brush.
- • Wear heavy leather work gloves to prevent crushed fingers and cuts from rough masonry.
📋 Step-by-Step Guide (6 Steps)
Mark the Layout Circle
Dry-fit a ring of retaining wall blocks on the lawn to establish the exact diameter. Mark the outer perimeter using spray paint roughly 3 to 4 inches wider than the stone circle, then remove the stones.
- • A clear, circular painted ring on the grass that is slightly wider than the dry-fit blocks.
- • Marking the circle too small, leaving no room to maneuver or add backfill.
Excavate the Trench and Pit
Dig out the marked circle to a uniform depth of 7 to 8 inches. Keep the outer trench walls vertical and scoop out all loose sod, roots, and organic matter.
- • A flat-bottomed circular hole 7 to 8 inches deep with clean, vertical earthen sidewalls.
- • Digging a bowl-shaped pit where the edges slope inward instead of remaining flat.
Lay Landscape Fabric and Compact Gravel Base
Line the excavated hole with landscape fabric to prevent weed growth. Pour 2 to 3 inches of crushed stone paver base over the bottom, rake it flat, and tamp it down aggressively until rock solid.
- • A smooth, firmly packed gravel surface inside the pit that shows no loose gravel shift when stepped on.
- • Level vial reads centered when placed across multiple spots on the gravel bed.
- • Tamping insufficiently, leaving loose gravel that will shift and destabilize the stone walls.
Lay and Level the Base Layer of Blocks
Set the first ring of retaining wall blocks onto the compacted base with tightly touching side joints. Check each stone with a bubble level front-to-back and side-to-side, tapping high spots down using a rubber mallet.
- • A complete, seamless ring of stones with all tops sitting flush and level with one another.
- • The top of the first course sits just slightly above ground level.
- • Leaving a single block high or low, which compounds errors and tilts every layer above it.
Stack Additional Wall Tiers
Place the second and third courses of wall blocks, staggering the vertical joints over the seams of the layer below. Press them tightly inward so the circle stays uniform and circular on all sides.
- • A multi-tiered circular stone wall where vertical seams are offset like brickwork.
- • No gaps larger than a hairline between neighboring blocks.
- • Aligning vertical joints directly on top of each other, drastically weakening wall stability.
Add Interior Drainage and Backfill
Fill the bottom interior of the pit with 2 to 3 inches of lava rock or coarse drainage gravel to protect the base and allow rainwater to drain. Backfill the exterior gap between the trench walls and blocks with gravel and compacted soil.
- • Interior floor is covered with an even layer of lava rock.
- • Exterior lawn perimeter is flush with surrounding turf, showing no open trenches or voids.
- • Using regular river rocks inside the pit bed, which contain trapped moisture and can explode when heated.
Credit: inspired by an original tutorial by Lowe's Home Improvement — watch the original on YouTube.
Don’t have everything?
- No Hand tamper? A flat end of an upright 4x4 wood post
- No Rubber mallet? A standard hammer hitting a scrap block of wood over the stones