Backyard fire pits are fun and festive, adding a welcome element to backyard gathering spots and boosting appeal for potential homeowners, too. While some DIY fire pits have a range of amenities—gas lines, seating—you can learn how to build a fire pit that isn't too expensive, difficult, or time-consuming.
This brick fire pit burns wood or charcoal. Although it includes a concrete base and mortared bricks, you can find premade retaining wall units for the DIY fire pit enclosure that may cut down on your labor. That means learning how to make a fire pit is easy for the amateur, requires no special tools, and is relatively inexpensive (about $600).
The best site for your DIY fire pit is one that's flat and about 10 feet in diameter, as well as far away from flammable structures such as decks or shrubs. For safety, you should also surround your fire pit ring with a nonflammable surface material such as granite or pavers.
As you are evaluating how to make a fire pit, allow roughly four hours to dig the pit and between eight hours and a full weekend to install the retaining wall and surrounding pavers. Although you should apply concrete adhesive to secure the top layer of retaining wall units, you don't need to mess with mortar.
Small, modular retaining wall units, used to create the fire pit enclosure, are available at most builder supply stores for $1-$2 each, and can mean a simpler process and less time for learning how to make a fire pit. A variety of colors, shapes, and sizes of units provides plenty of room to use your imagination as you select the color and style best suited to your yard.
Check your local building codes. Some municipalities prohibit open fires, while others have size and placement restrictions. Before you make a plan or buy a brick for a DIY fire pit, look into the rules in your area.
Mark out the DIY fire pit outer perimeter, inner edge, and center. Once you've gotten the go-ahead from your local building department, use a garden hose or string to mark out the size and location of the inside wall of your fire pit. (For convenience and ease of use and construction, most DIY fire pits are circles.) Using your markings as a guide, insert a wooden rod in the center of this inner circle. Then, cut a string the length of half the diameter of your DIY fire pit. Using the string and a can of spray paint, mark the inside of your fire pit. Paint another circle, this one an additional 12 inches outside your original circle. These form the boundaries of the trench.
Dig a trench. Using the painted outline as a guide, dig a 12-inch-wide by 10-inch-deep trench.
Fill the trench. Line the bottom of the trench with a 2-inch-thick layer of gravel; tamp it firmly down. Working quickly, cover the gravel with concrete until it reaches ground level. Remove any air pockets with a shovel, and level with the side of a 2x4. Let the concrete harden, then cure according to package directions.
Mist the cured concrete with water; spread with refractory mortar according to package directions. Leave three equidistant 3/4-inch gaps in this first course to serve as air vents.
Dry-lay a second course of 6-inch manhole blocks over the first (do not use mortar). The blocks should be flush with one another, and the internal edges should line up from first layer to second layer (you will have a small outer lip).
Mist the blocks of the first and second course with water, then apply surface-bonding cement to the exterior. Smooth the surface with a wet trowel. Keep the top edge clear of cement to ensure that the cap will bond with the wall, and do not cover the air vents.
Cut fireproof brick capstones into wedges using a circular saw with an abrasive masonry blade and chisel (wear safety goggles). After surface-bonding cement has cured, mist the fire pit with water. Fill in the block hollows, and add a coating of mortar to the top edge. Top mortar with brick wedges. Let the fire pit cure for 30 days.
To surround the pit with pavers, create a 4- to 6-inch gravel base topped with 1 inch of coarse concrete sand. Lay the pavers in the pattern of your choice. Some patterns let the bricks align on the edges, while others create a staggered layout with every other brick sticking out. Creating a smooth edge is a more complicated process because it requires you to cut bricks as necessary. After the pavers are in place, install a plastic or aluminum edge-restraint around the edges of the pavers to keep them from moving. Sweep concrete sand into the joints until joints are full; compact the surface of the pavers with a hand compactor or rented plate compactor.