Chimney Champions is a Jacksonville, FL chimney service company staffed by CSIA certified technicians and a National Chimney Sweep Guild member, serving residential customers who own wood-burning fireplaces. One of the most common issues Chimney Champions technicians see in Jacksonville homes is damage caused by burning the wrong fuel in the wrong system.

Not all fireplaces are built the same. Understanding whether your fireplace is a masonry or a prefabricated system determines which burning practices keep it safe and functional.

What Is a Masonry Fireplace?

A masonry fireplace is built on-site from brick, stone and mortar, with a firebox, smoke chamber and flue constructed as part of the home’s structure. Masonry fireplaces are designed to handle sustained high heat and are generally more tolerant of radiant temperature than factory-built units.

What Wood Works Best in a Masonry Fireplace?

Seasoned hardwoods produce the cleanest, most efficient burn in a masonry fireplace. Suitable choices include:

  • Oak
  • Hickory
  • Maple
  • Ash

Hardwoods should be dried for 6 to 12 months before burning. Properly seasoned wood burns longer, produces more heat, creates less smoke and reduces creosote accumulation in the flue. For a deeper look at which species perform best, see the best and worst types of wood to burn in your fireplace.

Burning unseasoned, or green, wood creates excessive smoke and moisture inside the flue. That moisture contributes to creosote accumulation, which is a primary factor in chimney fires.

What Is a Prefabricated Fireplace?

A prefabricated fireplace, also called a factory-built fireplace, is an engineered metal unit manufactured to a specific size and heat rating, then installed as a finished assembly. Prefabricated fireplaces are more sensitive to high heat than masonry systems because their metal components have defined temperature limits set by the manufacturer and verified through product testing.

How Should You Burn Wood in a Prefabricated Fireplace?

Prefabricated fireplaces require well-seasoned hardwood and moderate fire sizes to stay within their rated operating range. Key practices include:

  • Use well-seasoned hardwood only
  • Burn moderate-sized splits
  • Avoid overloading the firebox
  • Follow the manufacturer’s guidelines for fire size and fuel type

Excessively large fires or improper fuel in a prefabricated system can warp metal components, crack refractory panels and damage the chimney liner. Overfiring is one of the most common causes of premature failure in prefabricated fireplaces.

In a typical case, a Jacksonville homeowner with a factory-built fireplace reports smoke backing into the room and a rattling sound during fires. A Chimney Champions CSIA certified technician inspects the unit and finds that repeated large fires using unseasoned wood have warped the firebox baffle and cracked the refractory panels. The panels are noted as requiring replacement, and the technician documents that the chimney liner shows early-stage creosote accumulation from the same burning habits. Correcting the fuel and fire-size practice stops the damage from progressing further.

What Should You Never Burn in Any Fireplace?

Certain materials are not safe fuel for any residential fireplace, whether masonry or prefabricated. These include:

  • Treated or pressure-treated wood
  • Painted or stained lumber
  • Construction scraps
  • Trash or cardboard printed with inks
  • Plywood or particleboard

Burning these materials releases toxic combustion byproducts, produces excessive soot and dramatically increases creosote accumulation. They can also damage chimney liners and fireplace components in ways that are not always visible during normal use.

To understand how wood breaks down during combustion and why incomplete combustion produces creosote, see this overview of the stages of wood combustion.

Why Does Fuel Choice Matter for Either System?

Using the correct fuel for your fireplace type reduces creosote accumulation, improves heating efficiency, minimizes smoke, protects internal components and reduces the risk of chimney fire. The NFPA 211 standard, which governs chimneys, fireplaces and venting systems, addresses fuel requirements and inspection intervals for both masonry and factory-built systems. Chimney Champions technicians work in compliance with NFPA 211.

Burning properly seasoned hardwood in the system it is rated for is the most straightforward way to reduce fuel-related risk in either fireplace type.

When Should You Schedule an Inspection?

A chimney inspection by a CSIA certified technician identifies whether your masonry or prefabricated system has accumulated creosote, suffered component damage or developed any condition that affects safe operation. Chimney Champions provides chimney inspections in Jacksonville for both system types. Technicians at Chimney Champions train annually through CSIA, CVC Coaching and All Star Relining and hold IAC2 certification alongside CSIA credentials.

If you are unsure which type of fireplace you have, or if you have questions about safe burning practices, call Chimney Champions at (904) 268-7200 or book an appointment online.

Frequently Asked Questions

How do I tell whether my fireplace is masonry or prefabricated?

A masonry fireplace has a firebox made of brick or stone with visible mortar joints, and its structure continues up through the home as a chimney built from the same materials. A prefabricated fireplace has a metal firebox, often with flat refractory panels on the sides and back, and connects to a metal or insulated pipe chase rather than a brick chimney. A CSIA certified technician can confirm which type you have during a chimney inspection.

Can I burn the same wood in a prefabricated fireplace as in a masonry fireplace?

The fuel type is the same: well-seasoned hardwood such as oak, hickory, maple or ash. The difference is fire size. Prefabricated fireplaces have rated temperature limits, so fires must stay moderate to avoid warping or cracking internal components. Masonry fireplaces tolerate more heat but still require seasoned wood to limit creosote buildup.

Does Jacksonville’s climate affect how I store or season firewood?

Jacksonville’s humidity slows the drying process for freshly cut wood, so locally sourced wood may need the full 12 months of seasoning, or longer, before it burns cleanly. Store wood off the ground in a covered, well-ventilated area to allow airflow. Wood that feels heavy, shows dark cut ends or hisses when burned is not adequately seasoned.

Is a certified chimney inspection required before I use a fireplace I have never used before?

NFPA 211 recommends an inspection before using any chimney or fireplace system that has not been evaluated. For a fireplace that is new to you, whether through a home purchase or a renovation, a Level 2 inspection by a CSIA certified technician is the appropriate starting point. See why hiring a certified chimney sweep matters for more detail on inspection levels.