Fire pits are trendy additions in many backyards. This popular outdoor feature must be solidly built with suitable materials to ensure it looks good, lasts a long time, and is safe, but you might have wondered if all fire pits need a liner.
All fire pits need some type of lining. A fire pit liner protects the integrity of the fire pit and provides a safe space in which to have a fire. Lining your fire pit with a metal liner or fire ring, fire bricks or granite, will ensure your fire pit will remain an attractive feature for longer.
Basic fire pit materials are available in DIY kit form, or you may decide to have one built by a contractor. The materials you select to build the fire pit from will largely determine if you need a separate fire pit liner. Let’s see what types of liners are out there and if you need to install one.
Does a Fire Pit Need a Liner?
There are two common kinds of fire pits. One kind is wood burning, and the other is propane or natural gas burning.
Both wood-burning and gas fire pits should have a lining to ensure that the fire pit remains a durable feature that will last for as long as possible. Extreme heat can quickly damage a structure, but fortunately, fire pit liners form a shield between the flames and the fire pit.
Firepits constructed from fire bricks don’t need separate liner because the bricks are heat resistant and act as a liner. However, you may still prefer the cleaner, more finished look provided by a neat-looking steel liner.
One of the limiting factors that make people question whether or not they need a liner for their fire pit is cost. Firepit liners are constructed from thick, durable steel and can be expensive.
Using a liner will extend the life of most fire pits, so the long-term benefits of using a liner may outweigh the cost of rebuilding the feature within a year or two. However, if you prefer a rustic look and your firepit is made of a fire-safe material, using a liner is optional.
Liners Used In Wood Burning Fire Pits
Most people automatically think of steel units when choosing a liner for their fire pit. Steel liners are convenient in that they usually only need to be fitted into any existing fire pit.
Dense materials such as fire bricks, granite, and poured concrete are also suitable as effective wood-burning fire pit liners. When constructing the fire pit, be sure to select a high heat mortar or fire clay mortar.
Two types of steel fire pit “liners” are commercially available. These are:
- The fire pit liner, which is closed at the base apart from water drainage holes
- The liner ring is a circular shape but is totally open at the base
The fire pit liner is used as an insert or drop-in liner that accommodates a wood-burning fire in a custom-built, above-ground fire pit.
Fire pit rings are used in ground-level, sunken, or raised fire pits. The pit ring prevents the soil surrounding the ground level, or sunken fire pits, from falling into the fire pit.
A liner ring also protects the outer cladding material from excessive heat and stabilizes the structure of raised fire pits.
Deciding whether to use a fire pit liner comes down to what type of fire pit you have, how long you want your wood-burning fire pit to last, and how heat resistant the materials are that the fire pit is constructed from.
A wood-burning fire is very destructive and, over time and can damage the integrity of fire pits walls if they are not adequately protected. The heating and cooling effect causes the materials used to create the structure to expand and contract. This eventually loosens the mortar or glue used to bind the fire pit bricks or stones.
Fires made in a fire pit can reach temperatures of close to 1400 degrees Fahrenheit. A fire pit liner’s job is to protect the integrity of the fire pit itself and ensure that the decorative cladding on the outside of the structure remains undamaged and securely in place.
When installing a liner, correct installation requires that an open gap is left open between the bottom of the fire pit liner and the ground below. This cavity allows the heat generated within the fire pit structure to dissipate.
Since it will be located outside, a wood-burning fire pit liner needs to be heat resistant and withstand a wide variety of weather conditions. Moisture is a factor that needs to be considered when choosing the most suitable fire pit liner for your setting.
Porous mortar, unfired bricks, and most natural rocks are unsuitable to use as fire pit liners. Moisture is drawn into porous materials and expands as it heats up when the fire is burning.
Moisture that becomes trapped in the lining of inferior fire pit material can exert massive force on the surrounding material, which may cause cracks or, in the worst-case scenario, may blow apart.
Liners Use In Propane Or Natural Gas Fire Pits
Gas-burning fire pits are usually smaller than wood-burning ones and are generally fitted with a pre-fabricated metal liner that houses the gas burner. The liner fits into the cavity within the fire pit.
The gas burner is often covered with decorative rocks such as larva rock to look good. The rocks also protect the flow of gas from the elements and form a protective layer between the burner nozzles and the flame above the stones.
A gas or propane burning fire pit is not exposed to the same high temperatures as a wood-burning fire pit as the gas and flame are directed upwards. The heat escapes out the top of the fire pit, and very little is exposed to the walls of the fire pit itself.
In most instances, the gas fire pits use a carbon steel or stainless steel liner to house the burner and flame and keep the decorative stones in place.
What Materials Are Best for Lining a Wood Burning Fire Pit?
Fireproof and water-resistant materials are best to use as a liner for any type of fire pit. The most frequently used and arguably the best materials for wood-burning fire pit liners are steel, fire bricks, and granite blocks due to their high heat tolerance, relatively low cost, and durability.
A firepit liner protects the adjacent fire pit materials from the heat of the fire contained inside. Stainless or high carbon steel liners are usually already painted with heat-resistant paint when purchased, which smartens up the appearance of any fire pit.
Commercially available metal firepit liners made from stainless or carbon steel can range from twenty to sixty inches in diameter. Most models come packaged in a modular form that requires assembly before installation. The assembly is usually quick and easy.
The thickness of the material is an important consideration. Steel fire pit liners are generally manufactured of steel between ten and twenty gauge thickness.
When selecting the thickness of a fire pit liner, try to strike a good balance between being thick enough to resist the rigors placed on it during burning and ease of transportation and handling.
Thicker liners can be ordered and built by custom manufacturers, but this will cost significantly more than an off-the-shelf product.
How to Care for a Steel Fire Pit Liner
All modern fire pit liners are coated with a protective heat-resistant coating that needs routine care to stay in tip-top condition. Carbon steel subjected to direct fire and moisture will eventually rust.
Mild surface rust is the start of more severe damage to the liner, so the sooner it is addressed, the longer your fire pit will last. An annual deep clean followed by a coat of heat-resistant paint will make your firepit liner last a lot longer.
To reduce the chances of your firepit liner rusting, keep it clean and dry. Fire pit ash is notorious for retaining water which, when left in the liner for an extended period, will promote the formation of rust. Firepit ash should be removed as soon as it has cooled down.
How to Maintain a Propane or Natural Gas Fire Pit Liner
Propane or natural gas liners require minimal maintenance. Most gas fire pits are filled with decorative lava rocks or lava glass.
It is advisable to remove these rocks approximately once a year or sooner if they show significant discoloration. Lava rocks or decorative stones can be removed and washed in soapy water.
Even though gas does burn fairly cleanly, the soot from the gas will discolor the rocks over time, and they may need to be washed thoroughly to restore the natural color of the stone.
It is good practice to remove the decorative stones filling the gas fire pit annually to inspect, clean, and refurbish the fire pit liner if needed. Should the liner show any sign of rust, the liner surface should be lightly sanded and repainted with heat-resistant paint.
Fire Pit Liner, Shapes, and Sizes
Fire pit liners are available in many practical and decorative shapes and sizes. Gas or propane fire pit designs are often very creative because they require minimal maintenance or cleaning.
Propane or natural gas fire pits lend themselves to striking designs as the gas burners can be molded into different shapes to accommodate virtually any design spec.
Custom-built fire pit liners can be manufactured, which can accommodate any design. Although the cost would increase significantly over standard units, the desired outcome can be spectacular in function and form.
Wood-burning fire pits can be built to virtually any practical size. The only limiting factor will be if you have enough wood to burn.
Wood burning fire pits are usually round, square, rectangular, or hexagonal as these offer the best seating configuration to accommodate people socializing around the fire pit.
Does a Portable Fire Pit Need a Liner?
Store-bought portable fire pits do not need a liner. The portable pits are most commonly made entirely from steel or a combination of a steel frame and a fire-resistant material forming the fire pit bowl.
Whether it is propane or wood-fueled, the bowl containing the fire will have been designed to work perfectly without any modifications required to enjoy the fire pit.
Materials That Should Not Be Used as a Fire Pit Liner
When building your fire pit liner, there are some things you should keep in mind to ensure that your fire pit lasts a long time, keeps looks good, and is always safe to use.
Under no circumstances should you ever use compressed concrete blocks as they are unsafe when exposed to high temperatures.
Porous materials such as paving stones, unfired bricks, sandstone, limestone, pumice, gravel, and river rocks retain dampness and must also be avoided. Moisture trapped in these materials expands as the heat increases.
If porous materials are used as a fire put liner and exposed to direct heat, the danger exists that the increasing pressure caused by the retained water may cause the stone to expand. This will cause the rock to either crack or explode.
Besides the danger of the unsuitable fire pit materials exploding, small cracks that develop in the construction materials of the fire pit will eventually lead to the loosening and degradation of the fire pit. This can look untidy, and the condition will quickly deteriorate, probably necessitating rebuilding the entire structure.
Fitting a suitable fire pit liner will undoubtedly make any fire pit more durable. The extreme heat of the fire will be contained and dissipated by a liner.
Materials such as steel or hard natural rocks such as granite cut into bricks, marble, and fire bricks are safe and reduce the risk of a fire pit being damaged by repetitive use.
The mortar used to lay bricks and adhesives commonly used when gluing decorative rock to a wall do not do well when exposed to continuous heat. A good quality fire pit liner will reduce the negative effect of heat exposure on these materials, so your fire pit remains in great condition for longer.
Final Thoughts
A fire pit liner significantly enhances the structural stability of the fire pit, contains the fire in a fire-safe receptacle, adds years onto the lifespan of your fire pit, and makes any style of fire pit look neat.
Ben has a bachelor’s degree in construction engineering. When not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies, you can find him at home with wife and two daughters. Outside of family, He loves grilling and barbequing on his Big Green Egg and Blackstone Griddle, as well as working on projects around the house.
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