How To Protect A Fireplace Mantel From Heat – A Guide

A mantel serves more purposes than being an aesthetically pleasing decorative shelf. The mantel adds cohesion to the fireplace, and it breaks up the solid wall of masonry. The mantel also serves as a heat barrier to framed pictures or TVs hung above. Although a mantel itself serves as a heat barrier, it too needs protection from fireplace heat.

To protect a mantel from heat, install it 12 inches away from the fireplace opening. Also, deflectors redirect heat away from the mantel. They can be added beneath the mantel or right on the fireplace opening. Finally, fire retardants help wood mantels resist heat damage.

Even though mantels don’t tend to get too hot, they can get warm to touch. Usually, this isn’t a problem, but you could run into some issues when you start decorating the mantel. To be safe, read this post to learn how to protect your mantel from heat!

How Do You Protect A Fireplace Mantel From Heat?

Protect a mantel from heat by using a device to redirect the heat. Those devices are deflectors and fireplace hoods. The best way to ensure the mantel is protected is to install it at the correct clearance. The clearance recommendation is typically right at 12 inches.

Direct heat from the fireplace will wear down the mantel over time and can cause it to become overheated—and in some cases, flammable. To protect the mantel from excessive fireplace heat, let’s look at two different methods.

Heat Deflection

Install a heat deflector below the mantel to help redirect the heat away from the mantel. These devices are deflectors and hoods. They are two different methods of redirecting heat and will be explained below.

A deflector is a piece of thin metal that is installed directly beneath the mantel and angled (usually at 45 degrees) away.  The deflector will “bounce” the heat off the metal plate and away from the mantel. This prevents the mantel from absorbing heat and overheating. The little bit of space between the mantel and the deflector allows for airflow, preventing overheating.

The deflector can be painted a similar color to the mantel to make it more conspicuous. If you are painting the deflector, be certain the paint is heat resistant and rated for use around a fireplace.

A hood is also made of metal and is installed at the top of the fireplace opening. It redirects the heat from going straight up into the mantel and instead pushes the heat out into the room. The hood not only protects the mantel and any décor above the fireplace from heat, but it also improves heat output into the room.


The distance from the top of the fireplace opening to the bottom side of the mantel is described as the clearance. Local building codes determine what the safe clearance is. Make sure the mantel is installed according to those codes to help protect it from wear.

As a rule, 12 inches of space from the top of the fireplace to the bottom of the mantel is considered a good clearance. However, this distance varies depending on the depth of the mantel (how far it sticks out from the wall).

How Hot Can A Fireplace Mantel Get?

As a rule, the temperature of the mantel usually doesn’t exceed 185 degrees Fahrenheit. Combustibles, defined as materials that can burn, can be heated around 117 degrees Fahrenheit above room temperature (which is commonly around 70 degrees Fahrenheit). A combustible above 200 degrees Fahrenheit is at risk of becoming a fire hazard.

Over time, wood (or any other combustible material) that is continuously exposed to temperatures over 200 degrees Fahrenheit will begin to char and deteriorate. Meaning, eventually they will catch fire. Dry wood slowly begins to ignite right around 300 degrees Fahrenheit, and sometimes at an even lower temperature if its exposure is continuous.

To frame these temperature references, a typical cup of coffee is between 150 – 170 degrees Fahrenheit and the average temperature for home water heaters is set at 140 degrees Fahrenheit. A mantel that reaches 200 degrees Fahrenheit will be very hot to touch and may cause injury to the skin.

Mantel Comparison; Wood vs. Masonry

Wooden MantelMasonry Mantel
Can be replaced more easilyUsually built into brickwork
Increased risk of ignitionLess likely to ignite
Traditionally installed on top of masonryIt may be structural to the fireplace
Prone to stainingProne to staining
Is combustibleNot likely to combust
It needs to be installed with proper clearanceClearance is not as much of an issue

Can Fireplace Mantels Catch Fire?

Mantels typically don’t heat up above 185 degrees Fahrenheit, which means they will never catch fire. However, when the fireplace is installed incorrectly, or there is not enough clearance between the firebox and mantel, a mantel made out of combustible materials could catch fire.

How far the mantel sticks out is also of influence on the exact clearance numbers. For every 1/8 inch that a mantel protrudes, another inch of clearance should be added.

Clearance is required on all sides of the fireplace opening. Accordingly, a mantelpiece (defined as a mantel shelf, plus trim down the sides) needs to be installed at a proper distance on all sides. Again, this is a minimum of 6 inches, but for every 1/8 inch that protrudes, another inch of clearance should be added.

Can I Make A Wooden Fireplace Mantel Fireproof?

Applying a fire-retardant product on the wood can help make it resistant to burning. However, the best way to fireproof a wood mantel is to take precautions to keep it away from high heat. This is done by installing it at the proper clearance and using devices like a deflector or fireplace hood to redirect the heat away from the mantel.

Fire retardant paints and clear coats are products that can be used on wood surfaces to help treat them against fire. Log cabins commonly use a clear coat fire retardant to protect the beautiful wood from catching fire.

The same can be done for a wood mantel. Whether you have a natural wood finish or a painted wood finish, look to use a fire-retardant material to increase protection for your mantel.

Dan Westfield

Hi everyone! My name is Dan and I currently have two fireplaces, a wood-burning and a gas one. I cannot live without them and love to share my passion with you all!

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