What To Put In The Bottom Of A Fire Pit? | Obsessed Lawn (2023)

A fire pit is an inviting addition to backyard patios and gardens, and a well-maintained pit will last for many years. When setting up an in-ground or portable fire pit in your yard, following certain best practices will allow you to enjoy your outdoor fire safely.

One of the easiest ways you can keep a wood burning fire pit in good shape is by adding sand to the bottom of the pit, whether it’s in-ground or a moveable steel container. The sand will insulate and absorb heat, containing the fire and protecting the pit materials. For gas fueled fire pits, only fire-safe stones should be added for decorative purposes and to cover the fuel pipes and burners.

Types Of Fire Pits

The precautions you take will depend on the type of fire pit you have. There are four different types:

• In-ground wood burning – These types of fire pits are made with a short square or circular stone wall to keep the fire contained. They usually have an inner steel fire pit ring or square insert to absorb the heat and keep the fire from dehydrating or cracking the stone barrier. The bottom of these open wood burning pits can be paved stone or gravel and should have a couple of inches of sand to absorb the heat from the wood.
• In-ground gas burning – This type of fire pit usually has a paved stone base and doesn’t need a sand liner since the flames will be produced by a burner that is raised off the ground. These fire pits may come with steel logs or be filled with decorative stones to cover and protect the piping.
• Portable wood burning – Movable wood burning fire pits are made of steel or another very high heat-tolerant metal. They frequently have legs to raise them off the ground, a solid base that probably has air holes for oxygen flow, a solid or grated metal body, and sometimes a grated metal cover. A layer of sand in the bottom of these types of fire pits will insulate and protect it from cracking and corroding from the heat.
• Portable gas burning – Portable gas burning fire pits are also made of steel and are fitted with piping and burners attached to a propane gas source inside the unit. These usually also come with lava rocks, fire glass, or other types of stone for decorative purposes.

Should I Put Stone In The Bottom Of My Fire Pit?

Fire pits can be built on stone foundations to help control the fire. In-ground wood burning fire pits are either placed on paved surfaces or are assembled on a layer of gravel and sand, while gas burning in-ground pits are usually built directly on a paved foundation. Moveable steel pits, whether wood burning or gas fueled, are also safest on a paved surface like a patio but can be safely used on a fire mat or on non-grassy ground.

Stone and steel are the best materials to use for a fire pit, as these have high heat tolerance and will take a long time to be damaged by fire if they do get damaged at all. They absorb heat and won’t burn or rust when taken care of properly. There are several different types of stone that are used for the different kinds of fire pits:

• Sand – Sand is made of lots of tiny stones and stone-like inorganic materials and is an excellent liner for in-ground and steel base fire pits. It acts as an insulator, a layer of protection that absorbs heat and distributes it evenly, so no one spot gets too hot. This is especially important for metal bottom pits since high temperatures concentrated in a few areas will weaken the metal. Most sand is either silica (white) or playground (tan), so what kind of sand you use in a fire pit may be based on your preference.
• Brick and patio pavers – These dense stones have very high heat tolerances, and many in-ground fire pits are built on a stone-paved surface to control the fire.
• Lava rocks – Lava rocks have high heat tolerance, and they help with drainage of your fire pit. They are best in gas burning units since they create an insulation around the piping and help evenly distribute flames and heat.
• Fire glass – This tempered glass is designed to withstand high heat and serve for decorative purposes in gas fueled fire pits. They shouldn’t be used in wood fires since the higher temperatures can shatter the glass.

River stones and other natural rocks aren’t recommended for the bottom of a fire pit, and even as decorative may pose problems. They absorb a lot of moisture and can easily explode when heated up.

What To Put Around A Fire Pit

Depending on the type of fire pit you have, one or another type of barrier may be an essential extra caution to take. All types of fire pits should be in an open area, like the middle of the yard or on an open paved patio, with a hose handy. Chairs should be kept 5 or 6 feet from the edge of the fire.

For in-ground fire pits, sand around the outer edges will help keep grass away from the pit and keep the surrounding area from catching fire. Portable fire pits that are set in a grassy area should have fire mats under them and should be kept in a grassless 6-foot diameter. Moveable wood burning or gas fueled fire pits shouldn’t be used on a wooden deck or on artificial turf grass.

Does A Fire Pit Need A Liner?

Adding a layer of sand or another type of stone to the bottom of a fire pit is the only liner that the unit or burning area will need. Mobile units can be placed on fire mats to deter any dropped embers from catching on to anything, and in-ground fire pits will often have an internal steel fire pit ring to absorb the heat and protect the outer stone wall.

What Can I Burn In A Fire Pit?

The best materials to burn in a fire pit won’t deteriorate the unit. Only wood or wood-based products should be burned in a wood burning fire pit. The best wood is hardwood pine, which holds little moisture and dries out very well. Wood pellets and wood bricks are also good options to burn in your wood fuel pit, as both are made of wood shavings, wood chips, and sawdust. These dry materials burn cleanly, not producing extra smoke or sparks.

You shouldn’t add anything flammable at all to a gas fueled fire pit or portable gas unit. Only decorative rocks or decorative steel logs can be used in these. No kind of wood should ever be put into gas fueled fire pits. The intense heat generated by the wood fire can damage the piping and burners and cause a risk of explosion of the gas source.

What Not To Put In A Fire Pit

One of the biggest mistakes you can make that will damage your fire pit is burning things that shouldn’t be burned. Most flammable materials shouldn’t be put into a fire, particularly:

• Accelerator liquid – Lighter fluid, gasoline, and kerosene should never be used for a bonfire or in your fire pits since they are toxic and pose a risk for explosion, in addition to eroding the metal and stone material Always use dry kindling to start wood fires. You will never need a solid or liquid starter for a gas burning fire pit.
• Plastic– Plastic materials (bottles, wrappers, bags, etc.), in addition to being toxic, will melt and be extremely difficult to remove from the units. Plastics should never be burned.
• Treated wood or furniture – Wood that has been treated for construction or furniture will give off chemical fumes in the same way that plastic and accelerator liquids do and shouldn’t be used for fires.
• Magazines or junk mail – Like treated wood, magazines and junk mail have chemical treatments like glosses and inks that give off toxic fumes and leave buildup in your fire pit.
• Green wood – While not toxic, green wood is moist and won’t burn well. It will pop and smoke and should be avoided in favor of dry, dead wood.

Cooking over an open fire is one of the biggest draws of having a fire pit, but only certain types of pits should be cooked over. In-ground wood burning fire pits are the best to cook over since there is no metal or piping to damage with drippings or any dropped food.

Steel wood-burning units can become difficult to clean if there is grease buildup, and not all of it may be caught by the sand lining. If you haven’t put any sand down, the grease can be difficult to clean off and will corrode and contribute to the deterioration of the base.

How Often Should I Clean My (Metal) Fire Pit?

Regular fire pit maintenance will have your pit giving you clean-burning fires over many years. Sand should be replaced every few burnings since it will begin to discolor and may collect moisture and dirt over time. Ash should also be removed from steel units to prevent buildup and deterioration of the bottom. The ash can hold on to moisture, leading to rust and other corrosion of the metal.

A steel fire pit unit should be washed with soap and water at least once or twice a year, depending on how often it’s used, and dried thoroughly to avoid rusting. Steel units should always be cleaned before putting into storage if it isn’t out year-round. Gas-fueled units should be cleaned regularly so there is no buildup in the burners or yard debris that can catch fire.

Pouring water on a fire in a metal container can damage the metal bottom of the unit, weakening it over time from the shocks of sudden temperature change. If this is done regularly, it will start to crack and crumble sooner than later.

When you’re finished with your fire in a metal unit, you should allow it to burn out and cool off completely before using water to rinse the ashes away. Be sure the metal dries well since any standing moisture can lead to rust.

Last update on 2023-02-14 / Affiliate links / Somes Images and Data from Amazon Product Advertising API