There are several reasons not to burn wood in your backyard: the smoke is an irritant and a pollutant, storing firewood takes up space, and burning wood throws off embers and sparks that can be dangerous. Instead of lighting your fire with wood, use clean burning alcohol fuel in a sleek burner, surrounded by an attractive, tumbled concrete block fire pit, built with your own hands.
Step 1 – Pick Your Spot
The ring of stones will be about 3 feet across, so you need at least that much level ground (better to have more for safe and easy access) with no overhanging trees or construction. Because you’re not burning wood, you don’t need a deep foundation, but you may have to clear some earth and level it, so the blocks have an even surface to lie on.
Step 2 – Lay the First Course
Whether you’re building with bricks or blocks or stone, the first course is always the most important. Set the tree ring blocks end to end, making sure they are snug and level. If they are, the following courses will be too. The angled shape of the blocks will automatically lay them out into a circle. You may have to use some finesse to get the last block in place, but once you do you’ll have a perfect circle.
Step 3 – Lay the Next Courses
This is as simple as picking up blocks and putting them down. Offset each block from the course below it, so the joints don’t line up, creating a brick pattern. This creates more stability. You don’t need any adhesive or mortar. The weight of the structure holds it in place, so the only tool you need is elbow grease. Go up to about 2 feet, which should be around 3 courses, depending on the size of your blocks.
Step 4 – Set the Capstones
This is the one layer that will be glued down. Gravity won’t hold the lighter capstones in place so use a masonry grade construction adhesive. With a caulking gun, spread a bead of adhesive on the top of the upper course and the bottom of the capstones. Set the capstones in the adhesive. Allow it to dry and cure for the time allotted on the label.
Step 5 – Install the Grate and Burner
Inside the ring, make a smaller ring 2 blocks high and topped with capstones. They don’t have to be tidy, but they do have to be stable. Set a barbecue grill grate on the inner ring.
And put your alcohol burner in the center of the grate. These burners are made of stainless steel and you can find them online or seasonally (winter) at big box stores and home centers. The top of the burner should be a few inches below the rim of the fire pit.
Place landscaping pebbles large enough to not fall through the grate all around the burner, until the grate is hidden and only the top of the burner shows.
Step 6 – Light It Up
Pour the alcohol fuel into the burner as directed in the instructions. It’s the fumes that ignite, so stand back and light the fire with a metal rod dipped in the fuel. The fire burns a brilliant orange and gives off a good amount of heat, but there are no sparks, no smoke and no smell. And check the label to be sure, but most fuels are food safe, so you can roast some marshmallows too.