How to Build a Firepit

Backyard DIY Firepit
Jesse Millan/Flickr/CC BY 2.0 

Imagine gathering with friends and family around an inviting, crackling fire built in your own backyard firepit. What could be cozier? 

Forty-eight inches outer diameter, 12 inches high, this DIY backyard firepit can be built in less than two hours. The outer ring is large enough for up to six guests to pull up a chair and chat, and the inner 32-inch diameter firepit provides ample room for a roaring fire.

Because this backyard project uses inexpensive masonry materials, costs are kept in check. No special skills are needed, either. The hardest part is transporting the heavy materials home and moving them into place. But with store delivery directly to your home, and with the help of a partner or two, back-breaking work is kept to a bare minimum. 

Tools and Materials

  • 57 retaining wall blocks (each block: 4 inches high, 8-1/2 inches wide, and 8 inches deep)
  • 64 square concrete pavers (each paver: 6 inches by 6 inches)
  • 12 bags of leveling sand (each bag: 1/2 cubic foot). For a tighter fit between the pavers, you may wish to use 10 bags of leveling sand as a base and 2 bags of polymeric sand to sweep across the top of the pavers.
  • Landscape block adhesive
  • Caulking gun
  • Shovel
  • Bubble level
  • Tape measure
  • Hammer
  • Twine (at least 18 feet long)
  • Broom
  • 4 stakes (you can use any kind of long thin scrap wood)

Check Local Restrictions

Before you build, check on local permitting requirements.

Some municipalities require a building permit even for simple firepits of this type that are not serviced by a gas line. If your home is part of a homeowners' association (HOA), you may be required to seek permission from the HOA board before building the firepit. Also check on restrictions about exposed fires in your area.

Find a Suitable Location

Locate the firepit well away from the house. Be sure to stay clear of windows that often get opened, as well as any kind of fan intakes and air conditioning units.

Mark the Area

With the tape measure, mark off an area 4 feet wide by 4 feet long. Drive stakes at each corner. Run the twine or string between the stakes. The inner section will be your dig area.

Dig the Foundation

With your shovel, dig out that area down about 2 inches deep. Removing the turf itself is sufficient depth since turf extends about 2 inches down into the ground.

Add Leveling Sand

Open the bags of sand and pour ten of the bags evenly throughout the work area. Make sure that the level of the sand is below turf level.

Set the Pavers

Set the concrete pavers on top of the sand, eight pavers to each side. Leave about 1/16-inch space between each paver (about the width of a credit card). Check for level with the bubble level and adjust individual blocks accordingly.

Sweep in Sand

Pour the two remaining bags of leveling sand on top of the pavers and use the broom to sweep the sand across the pavers. Sand will fall between the pavers, helping to lock them into place. A majority of the sand will fall in the perimeter, between the pavers and the excised turf, further helping to hold the pavers in place.

Set the First Tier of Blocks

Portion out a third of the retaining wall blocks to use for the first tier. Create a ring from these blocks, setting them directly on the concrete pavers. When set side-to-side, these blocks should form a ring with a 48-inch outside diameter. 

Glue the Blocks

Cut off the end of the tube of landscape adhesive and use the piercing device that is built into the caulking gun to pierce the end of the tube (through the nozzle). Fit the landscape adhesive into the caulking gun and pump a few times to work the adhesive into the nozzle.

Run a thick bead of adhesive around the ring of blocks, on top. One circle of adhesive should be enough.

Set the Second and Third Tiers of Blocks

Place the second tier of blocks on top of the first tier. Stagger the blocks so that each block of the second tier straddles two blocks of the first tier.

This is a common method of arranging blocks that provides greater strength to the unit.

Lay a bead of landscape adhesive on the second tier. Lay the third and final tier of blocks on top in a similar staggered fashion. Do not add adhesive to the top of the third tier.