Building a Cinder Block Fire Pit

Lead Image
  • 4-8 hours
  • Intermediate
  • 50-500
What You'll Need
Landscape paint
Cinder blocks
Garden soil
Mortar mix
Pea gravel
Lava rock

A block fire pit can be easily built with affordable utilities like cinder blocks. They are readily available and offers years of maintenance-free performance. Additionally, the process of building one is a project that most DIYers can do without too much stress.

Step 1 - Get Started

It is vital that you first gain the legal/regulatory permissions for building a fire pit on your property. In some states, a small fee has to be paid as well.

Choose an appropriate spot for building the cinder block fire pit. It should be situated away from the surrounding plants and walls and away from surfaces like vinyl sidings or wood that can catch fire. The chosen spot should be within an accessible distance from a high-pressure water source as well. This ensures that a garden hose can be quickly pulled out in case of a fire emergency.

Step 2 - Mark Measurements and Dig Fire Pit

You can use any brand of landscape paint for marking a circle in the chosen spot. Using the paint, draw a circle that is about four feet in diameter. This is the average circumference for fire pits in residential spaces. You can also use a shovel for this purpose though this can be a bit tedious. After you’ve finished marking your spot, take a shovel and dig about six inches down along the drawn circle.

Step 3 - Lay First Layer of Cinder Blocks

Start laying the cinder blocks, end-to-end, within the circular dug-out. The holes of the cinder blocks should be facing upwards and should be a bit tilted toward the outer edge of the fire pit circle. Using the shovel, dab at the cinder blocks to ensure that they are packed tightly.

Step 4 – Lay Second Layer

In the same manner, place the second row of cinder blocks upon the first tier. Ensure that the central points of cinder blocks in the two rows are systematically aligned. This means that the central holes of the blocks should be exactly above each other. Check at this time to make sure the blocks are level and that they are aligned uniformly without any gaps between the two rows. The first two rows are mandatory to set up the cinder block pit. You can add the third and fourth layers as per your personal preferences.

Step 5 - Consolidate Outer Layer

Spread some garden soil over the blocks to fill in any gaps. Then, prepare your mortar according to packaged instructions. Using a trowel, lay down the first layer of mortar on top of the cinder blocks. Push the rebar through the block holes and hammer it if necessary. The rebar should only protrude about four inches. Fill the remaining cinder block spaces with the mortar mix, and allow the fire pit to dry out overnight.

Step 6 - Consolidate Inner Layer and Finish Up

The next day, cover the inside surface of the fire pit with some pea gravel. Then, continue the consolidation by adding some lava rock. Secure the outer layer of the cinder blocks with some more mortar, and once again, allow the fire pit to dry out for a day or two. Place the wire mesh or fire grate over the mouth of the fire pit to finish the project.