How to Choose a 36-Inch Smokeless Fire Pit Insert

On this page (6 sections)

1. What does 36 inches measure on a fire pit insert?
2. Why does the wall gap matter for smokeless burning?
3. What should you check before installing the insert?
4. Which products may help with a 36-inch insert setup?
5. How do you choose between an insert and a complete fire pit?
6. What is the decision rule for a 36-inch insert?

A 36-inch smokeless fire pit insert can work in an existing enclosure only if the opening leaves room around the ring for airflow and its base vents stay clear. Measure the opening, check the insert’s outer and inner dimensions, and follow its installation guidance before setting it in place.

The Iron Forge Tools ring in this guide measures 36 inches across the outside and 30 inches across the inside. Its guidance calls for a 1-inch wall gap, a rock base and open vents at the base for airflow.

For the basic airflow idea, start with what a smokeless fire pit is. If you're comparing insert styles, see our best smokeless fire pit inserts guide.

What does 36 inches measure on a fire pit insert?

On the Iron Forge Tools ring, 36 inches is the outside diameter, while the inside diameter is 30 inches. That six-inch difference accounts for the ring’s width, so the number alone does not tell you how large an opening it needs.

Measure the enclosure where the insert will sit. Check the opening from side to side in at least two directions, since a stone or brick pit may not be perfectly round.

The ring’s installation guidance asks for a 1-inch gap between the insert and the wall. That means you need enough clear width for the ring and the gap on both sides, not just an opening that measures 36 inches.

How to measure a 36-inch smokeless fire pit insert opening

Measure the inside width across the enclosure at the height where the insert will rest. Repeat at a right angle and note any sections that narrow, bulge or have mortar joints protruding inward.

For a round opening, compare the narrowest measurement with the insert’s outside diameter plus the clearance required by its instructions. Don’t assume a 36-inch-wide opening is a fit for a ring with a 36-inch outside diameter.

Check the depth and support surface too. The Iron Forge Tools ring is 10 inches high, so confirm the enclosure lets it sit at the intended level while leaving base vents open.

Why does the wall gap matter for smokeless burning?

A clear gap helps air move around the insert, which supports the airflow that secondary combustion needs. A ring pressed tightly against masonry can restrict that path and work against a cleaner burn.

Iron Forge Tools recommends a 1-inch gap between its ring and the wall. Treat this as a model-specific requirement, and use the instructions for any other insert you consider.

Base airflow matters as well. Keep the vents clear of packed soil, ash and construction materials, and follow the insert’s guidance for the base beneath it.

The goal is not simply to make a ring fit. The enclosure must leave the air paths open while supporting the insert securely.

What should you check before installing the insert?

Check fit, clearance, base support and ventilation together before you build around a ring. A suitable opening that blocks the vents or crowds the walls can still prevent the intended airflow.

Use this pre-installation list:

• Measure the enclosure’s narrowest inside width and compare it with the insert’s outside diameter.
• Confirm the required wall gap around the full ring.
• Check the insert height against the finished pit height.
• Identify where the base vents are and keep them open.
• Follow the instructions for the base material and support.
• Plan for ash removal and access for cleaning.
• Confirm whether the insert is fixed in place or designed to move.

Iron Forge Tools describes its ring as a permanent installation for above-ground or sunken setups, not for campground transport. It also recommends a rock base and a weatherproof cover for its ring.

If the enclosure is on a deck or patio, review the surface and clearance guidance for the complete setup. Our best fire pits for patios guide can help you compare standalone options and patio placement needs.

Does the insert need a rock base?

The Iron Forge Tools ring’s guidance recommends a rock base. Follow the instructions for the model you select, and make sure the base does not cover the vents or shift the ring into contact with the enclosure wall.

A stable, level support helps the ring stay in position. If your existing pit has a sloped, uneven or crumbling base, resolve that before installation rather than using the ring to bridge an unsupported area.

Which products may help with a 36-inch insert setup?

The Iron Forge Tools ring is the direct match for a 36-inch fixed insert project among these products. The other two are accessories or complete fire pits, so they suit different needs.

The Solo Stove Surround is a protective accessory with a perforated tabletop and adjustable feet. It is designed around a Yukon fire pit, so check compatibility with your specific fire pit before considering it for an enclosure project.

This Iron Forge Tools ring is the insert choice here for a permanent backyard build. Its 36-inch outside and 30-inch inside measurements make it important to verify both opening clearance and usable fire space.

The TIKI Patio Fire Pit is a standalone wood-burning unit, not a 36-inch ring for a built enclosure. Its listed body dimensions are about 24.75 inches across and 18.75 inches high.

How do you choose between an insert and a complete fire pit?

Choose an insert if you already have a suitable enclosure and can preserve the required clearances and airflow. Choose a complete fire pit if you want a self-contained unit or your existing opening cannot fit an insert correctly.

If a grill surface matters, compare smokeless fire pits with grills.

If you are considering a propane build, see our DIY propane fire pit guide.

An insert can suit a permanent backyard feature. It requires more attention to opening measurements, base support, vent access and wall clearance than a complete freestanding unit.

A complete fire pit may be easier to place, but it still needs safe spacing from nearby materials and use according to its instructions. Before using one indoors, review smokeless fire pit indoor safety.

For a broader comparison of stand-alone options, see best fire pits for smokeless burning.

Consider the fuel and cleanup routine too. Read what firewood works best in a smokeless fire pit and which firewood is best for a fire pit before planning regular use.

What is the decision rule for a 36-inch insert?

Pick the Iron Forge Tools ring if your enclosure can fit its 36-inch outside diameter, preserve the recommended 1-inch wall gap, support a rock base and keep base vents clear. Choose a complete fire pit if those conditions do not fit your existing space.

Before buying, verify your measurements against the insert instructions and check that the setup suits the surface and location. If your enclosure is too tight or uneven, adjust the build plan before lighting a fire.

If you plan to burn pellets, check using pellets in a smokeless fire pit.

Frequently asked questions

Does a 36-inch fire pit insert fit a 36-inch opening?

Not necessarily. A 36-inch outer diameter needs an opening large enough for the insert plus its required clearance from the surrounding wall.

Measure the opening at several points and check the insert’s installation guidance before buying.

The Iron Forge Tools ring calls for a 1-inch gap between the ring and wall.

How much space should be between a smokeless insert and the wall?

The Iron Forge Tools 36-inch ring calls for a 1-inch gap between the ring and wall to support airflow. Other inserts may have different requirements, so use the instructions for the model you choose and confirm the opening can provide that space all the way around.

Do smokeless fire pit inserts need vents?

Airflow is central to secondary combustion, so an insert setup needs a clear path for air to reach the fire. Iron Forge Tools advises leaving vents at the base and using a rock base for its 36-inch ring.

Check the specific insert’s instructions before building the enclosure.

Can a 36-inch smokeless fire pit insert be portable?

The Iron Forge Tools 36-inch ring is designed for fixed installation and is not intended for transport to a campground. If you need a portable fire pit, compare complete standalone models and their dimensions instead of assuming an insert can move safely once installed.