Fire Pit Construction: Stone, Block, and Steel Options for Your Backyard

A fire pit is one of the most popular backyard projects because the result is immediately usable and the construction is not complicated. But fire codes, setback requirements, and material choices determine whether your fire pit is legal, safe, and lasting. Gas and wood-burning fire pits have different construction requirements, different operating costs, and different experiences. Here is what you need to know before breaking ground.

Check Local Codes First

Before buying materials, call your local fire department or building department. Many municipalities regulate open flames with specific requirements that vary widely from one jurisdiction to the next. Common regulations include fire pit size limits (usually 3 feet in diameter or less for wood-burning), setback distances from structures (typically 10 to 25 feet from any building, fence, overhang, or property line), and fuel type restrictions.

Some HOAs prohibit wood-burning fire pits entirely. Some cities allow them only with a permit. Some counties in fire-prone areas ban open fires seasonally or permanently, often with burn bans announced during dry spells. A $500 fire pit project can turn into a $500 fire pit demolition project if you skip this step. The call takes five minutes and could save you from tearing out finished work.

Gas fire pits face fewer restrictions than wood-burning because they produce no sparks and can be shut off instantly. But they still need clearances from combustible materials and may require a gas line permit if you are running natural gas from the house. Check whether your municipality requires a licensed plumber for the gas connection, as most do.

Wood-Burning Fire Pits

A basic in-ground wood fire pit is a ring of fire-rated blocks or stones set in a shallow depression with a gravel base for drainage. Start by marking the circle on the ground. For a standard pit, 36 to 42 inches in interior diameter works well for a group of four to six chairs around it. Dig out 6 inches of soil within the circle, add 4 inches of compacted gravel, then stack your blocks or stones to the desired height, typically 12 to 18 inches above grade.

Use fire-rated materials only. This is not negotiable. Standard concrete blocks, clay bricks, and river rocks can crack or explode when heated because moisture trapped inside the material turns to steam and expands rapidly. Fire bricks, fire-rated retaining wall blocks (sold specifically for fire pit construction), or natural stone that is not porous, such as granite or bluestone, are safe choices. Sandstone, limestone, and any rock that has been submerged in water should not be used.

Line the interior with a steel fire ring or fire-rated fire brick. This protects the outer block wall from direct flame contact and extends the life of the pit significantly. Steel fire rings are available in standard diameters (28, 30, 36 inches) and cost $40 to $100. They drop into the center of the block ring and keep the fire contained.

Leave gaps or weep holes at the base of the block wall for airflow and water drainage. A fire pit that holds water after rain becomes a breeding pool for mosquitoes, and the trapped moisture makes it difficult to start a fire until everything dries out. Two or three 1-inch gaps at the base course, evenly spaced, provide sufficient drainage without compromising the structure.

Gas Fire Pits

Gas fire pits use a burner kit installed inside a non-combustible enclosure. The burner connects to a natural gas line or a propane tank. Natural gas provides unlimited fuel from the house supply and eliminates the need to refill tanks. Propane is portable and does not require running a gas line, but you will need to swap or refill tanks regularly.

The burner kit includes the burner ring (typically stainless steel), a gas valve with a key or electronic ignition, a flex line for connecting to the gas supply, and lava rock or fire glass to cover the burner and distribute heat. Kits range from $150 to $600 depending on BTU output, materials, and ignition type. A 60,000 BTU burner is typical for a residential fire pit and produces a visible flame ring about 12 to 18 inches in diameter.

Running a natural gas line to the fire pit requires a licensed plumber in most jurisdictions. The gas line must be buried below the frost line (which varies by region, typically 18 to 48 inches deep) and connected with approved fittings. This is not a DIY project unless you are a licensed gas fitter. An improperly connected gas line is an explosion hazard, and insurance companies will not cover damage from unlicensed gas work.

Propane fire pits can use a standard 20-pound tank (the same size as a grill tank) hidden inside the fire pit base, or a larger buried or remote tank with an underground line. A 20-pound tank runs a medium-output burner (around 40,000 to 60,000 BTU) for about 8 to 10 hours of use. For most homeowners, that is two to four evenings of use before a refill.

Building the Enclosure

For a stone or block enclosure, set the first course on a compacted gravel base. Level each block carefully because the first course determines how straight and stable the entire structure will be. Use construction adhesive between courses. Do not dry-stack a fire pit that will be left unattended or used by children, as dry-stacked blocks can be knocked over or shifted by wind, pets, or normal use.

A cap course on top finishes the look and provides a surface for setting drinks or resting arms. Use the widest flat stones or cap blocks you can find. Adhere them with construction adhesive rated for high temperature. Standard landscape adhesive works for the outer courses, but the cap course and any block within 6 inches of the flame should use heat-rated adhesive.

For a gas fire pit, frame the enclosure from steel studs and cement board rather than wood. Cover the exterior with stone veneer, stacked stone, or stucco for appearance. The interior must be non-combustible throughout. No wood framing, no plywood, no composite materials. The burner generates sustained heat that will ignite wood framing over time even if it does not catch fire immediately.

Include an access panel in a gas fire pit enclosure so you can reach the valve, burner connections, and propane tank without dismantling the structure. A removable panel on the back side (away from seating) works well. Maintenance access is the detail most DIY gas fire pit builds forget, and it becomes a major frustration the first time you need to troubleshoot a burner issue or swap a propane tank.

Safety and Maintenance

Keep a fire extinguisher or garden hose within reach when using a wood fire pit. Never leave a fire unattended. Douse the fire completely with water before going inside for the night. Coals can reignite hours after the visible flames are out, especially on windy nights. Stir the ash while dousing to make sure water reaches all the embers.

Clear a 10-foot perimeter around the fire pit of all combustible materials: dry leaves, mulch, dead grass, overhanging branches, and outdoor furniture with fabric cushions. Replace mulch with gravel or stone in the immediate fire pit area. A stray spark on dry mulch can start a landscape fire in seconds.

Cover the fire pit when not in use. A metal or stone cover keeps water out (preventing freeze-thaw damage to the masonry), blocks debris from clogging gas burner ports, and keeps animals from nesting in the ash. For wood fire pits, a simple sheet metal lid works. For gas fire pits, use the cover specified by the burner kit manufacturer.

Clean ash from a wood fire pit after every 3 to 4 uses. Ash absorbs moisture, promotes rust on steel fire rings, and blocks the drainage weep holes at the base. Let ash cool completely (at least 24 hours after the last fire), then scoop it into a metal container. Do not use a plastic trash bag or cardboard box for ash disposal. Even cold-looking ash can contain live embers.

Cost Comparison: Wood vs. Gas

A basic wood-burning fire pit using retaining wall blocks costs $200 to $500 in materials. You can build it in a single afternoon with no specialized tools beyond a shovel, a level, and a rubber mallet. Ongoing costs are firewood ($150 to $300 per cord, with one cord lasting most homeowners an entire season) and replacement of the steel fire ring every 5 to 10 years.

A gas fire pit with a stone enclosure and a burner kit runs $800 to $2,000 in materials. Adding a natural gas line from the house adds $500 to $1,500 for the licensed plumber. Propane operation costs roughly $15 to $25 per tank refill. The advantage is instant on/off, no smoke, no ash cleanup, and no spark risk.

The choice between gas and wood comes down to how you want to use the fire pit. Wood fires provide the crackling sound, the smell, and the experience of tending a fire. Gas fires provide convenience, cleanliness, and fewer restrictions in most jurisdictions. Both last for years with proper construction and basic maintenance.

Frequently Asked Questions

How much does a fire pit cost to build?

A basic wood-burning fire pit using retaining wall blocks costs $200 to $500 in materials. A gas fire pit with a stone enclosure and a burner kit runs $800 to $2,000. Adding a natural gas line from the house adds $500 to $1,500 for the plumber.

Can I put a fire pit on my deck?

Wood-burning fire pits should never go on a wood deck. Sparks, radiant heat, and falling embers create a serious fire risk. Gas fire pits can go on composite or wood decks if you place a fire-rated pad underneath and maintain manufacturer-specified clearances. That said, most deck builders and insurance companies recommend against any fire pit on a deck.

What burns best in a fire pit?

Seasoned hardwood (oak, maple, hickory) with less than 20 percent moisture content. Softwoods like pine burn fast, produce heavy smoke, and throw more sparks. Never burn treated lumber, plywood, or painted wood. The chemicals in the treatment produce toxic fumes and leave hazardous residue in the ash.

Related Reading

• Patio Paver Installation
• Outdoor Lighting Guide
• Concrete Basics Tools