What Are Fireplace Bricks?

Fireplace bricks are refractory firebricks, high-density clay blocks engineered to withstand extreme heat and repeated thermal cycling. They line the combustion chamber of a fireplace and protect structural components from damaging temperatures.

What is the Difference Between Firebrick and Fireplace Refractory?

There are two distinct types of heat reflector with different applications. They are not interchangeable.

Type One: Masonry Firebrick

Individual clay bricks used in traditional masonry fireplaces.
Installed with refractory mortar.
Purpose: protect structural masonry and maintain proper firebox geometry.

Type Two: Factory-Built Refractory Panels

Precision-molded panels designed for specific manufactured fireplace models such as Heatilator and Heat & Glo
Model-specific and non-interchangeable.
Purpose: provide thermal protection while matching exact manufacturer specifications.

How to Replace Fireplace Bricks?

Masonry Fireplace Firebrick Replacement

Step 1: Assess the Damage

Safe to use: Hairline surface cracks, chips or minor cosmetic wear are okay.
Requires replacement: Loose or missing bricks with deep fractures or crumbling. Spalling gaps between bricks with loose or missing firebrick makes the firebox non-compliant with manufacturer safety standards.
We find that fireplaces can still operate just fine with some damage firebricks, but generally it is a good practice to replace them to get max heat from your heating appliance.

Step 2: Remove Damaged Bricks

Chip away old refractory mortar with a chisel and hammer
Do not damage the structural firebox Remove debris and dust

Step 3: Prepare Replacement Bricks

Use 1¼ inch refractory firebrick
Cut to fit using a masonry saw or angle grinder
Dry-fit to confirm proper sizing
You can also buy a replacement set from your local specialty hearth shop and save a ton of time! We highly recommend this option as opposed to cutting your own firebricks.

Step 4: Install with Refractory Mortar

Use refractory mortar only
Apply mortar to all contact surfaces
Maintain original joint thickness
Preserve the original firebox dimensions

Step 5: Cure Properly

Air-dry your freshly installed firebricks for 24 to 48 hours
Build three or four small break-in fires
Gradually increase your first few fires in size to prevent steam-spalling. (This keeps concrete from rapidly chipping apart due to the high-pressure steam.)

Factory-Built Fireplace Panel Replacement

Factory-built fireplaces require exact OEM replacement panels. Universal parts will not fit correctly and may void the unit listing. Buy your replacement fireplace panels from an authorized dealers through your appliance’s manufacturer.

What Do You Need to Know When Buying Replacement Fireplace Refractory Panels?

This is the most important piece of advice we can give you:

We highly recommend replacing all of your fireplace refractory panels at the same time! (Even if only one panel is currently broken.)

When you remove that single panel for replacement, it is common for the rest of the panels to break in the process. If you are buying only one refractory panel for replacement, please pause and reconsider. Our years of experience has shown that buying the entire refractory panel replacement set from an authorized dealer is the best way to ensure your long term safety and warmth.

When Should You Replace your Fireplace Refractory Panels?

Cracks wider than 1/8 inch
Loose or broken panel sections
Significant surface chipping
Any major structural compromise

How to Replace Fireplace Refractory Panels?

Remove Components
Take out the grate, log set, and media
Photograph the existing layout
Release Panels
Remove retaining clips or brackets Typical order: floor, back, sides
Install OEM Panels
Follow the manufacturer’s sequence, usually back, left, right, floor
Maintain required expansion gaps
Panels may friction-fit or attach with clips depending on model
Reinstall retainers and hardware
Replace grate and log set
Confirm proper fit with no gaps

How to replace a fireplace refractory in a Hearth & Home Technologies appliance?

1. Install back refractory first. The back refractory panel should rest against the back of the firebox. To avoid damage, hold the back refractory in place until a side refractory panel is installed.

2. Install the right refractory panel next. Bend the refractory tab down to support and hold the refractory in place.

3. Repeat procedure for installing the left refractory panel.

If you have any questions, please reach out to your manufacturer. There are many guides specific to your fireplace available via manufacturer websites and customer support.

Fireplace Safety Tip: Why are damaged firebricks or refractory panels dangerous?

Structural damage exposes walls and framing to temperatures exceeding 1000°F
Fire hazard increases when heat transfers into combustible materials
Code violation, because intact and heat-resistant firebox surfaces are required

Firebrick vs Refractory – Quick Fireplace Reference for Beginners

Fireplace bricks or panels are heat-resistant surfaces that protect a heating appliance like a fireplace, stove or firepit.
Masonry firebricks are individual bricks installed with refractory mortar.
Factory-built refractory panels are prefabricated and model-specific.
Always use the proper refractory materials!

Contact a CSIA or NFI certified technician for inspection or repair if needed.

Learn more about fireplace safety:

When it Comes to Fireplaces, Your Safety is Our Priority

Do not use a fireplace with missing bricks or severely damaged panels. Cracks and chips are okay, but replacement is encouraged if you are missing a brick or a panel in your fireplace.

Our mission is to help you stay warm and save money. Our years of experience give us the ability to write informational posts like this one and answer questions on your fireplace journey. Thank you for taking the time to read and if we can be of any further service, please do not hesitate to reach out to us at The Stove Shop.