Building a Fireplace Mantel from Scratch

New fireplace mantel.

A fireplace mantel is one of the highlights of any living room with a fireplace. Also known as the mantelpiece or chimney piece, fireplace mantels originate from medieval time periods and serve both practical purposes as well as aesthetics.

They are an interior designer’s dream because they look so dominating and beautiful, and are sometimes built with gorgeous and rare types of stone or brick.

Is it possible to build a fireplace mantel from scratch?

You bet. DIY fireplace mantels are a source of pride as you get to design and build it yourself, and will surely get the attention of visitors at your home. Here’s all you need to know to get the project started…

Understanding Fireplace Mantels

Fireplace mantels were originally constructed in medieval times when the fireplace was the primary source of heat in a building. The mantel served as a hood that projected over a fire grate in order to catch the smoke.

Over time fireplace mantels have become designed less for practical purposes and more as decorative framework around the actual fireplace unit. You’ve likely seen some beautiful mantels over your years and it is hard to beat the elaborate design and fine masonry of some of the finest fireplace mantels.

Today fireplaces are generally not the primary source for heating. Instead, fireplaces are used more for show and leisure thanks to contained heating systems like furnaces and electric heating.

Modern fireplace mantels are designed to enhance the grandeur of an interior room. There are countless styles to model after. Materials used for the mantel range from expensive wood to brick to beautiful stone.

When building a fireplace mantel from scratch you must focus on making sure the unit is strong and durable.

Tools You Will Need to Build a Fireplace Mantel

So you want to tackle your own fireplace mantel DIY project? Here are the basic tools and accessories you need:

  • Safety glasses
  • Sandpaper
  • Stud finder
  • Leveler
  • Wood glue
  • Construction adhesive
  • Decorative molding
  • Painters plastic
  • Pneumatic brad nailer and air compressor
  • Table saw
  • Circular saw

The whole reason most people want to build their own custom fireplace mantel is to dream up the design. There is nothing wrong with that as you want something that you can feel proud about and cherish for years!

Step 1: The Design

We recommend that you sketch your design on a sheet of paper. You’ll want the measurements of your firebox to fit the dimensions. Then, you can let your imagination take you where you prefer.

Things you will want to consider including questions like:

  • What do I want the mantel to be made of?
  • What color(s) do I want it?
  • Do I have a particular mantel style in mind or type of accents I want to use?
  • How wide do I want the mantel shelf to place items on it?

We recommend starting with a minimum of a six inch mantel on top. That will give you a wide enough shelf to place most ordinary objects and decor.

Step 2: Build the Legs (Or Sides)

The technical term for the sides of a mantel are the “legs”. The two columns on either side of the fireplace help support the shelving above the fireplace.

Once you have the measurements of the firebox you can start making cuts after you settle on a type of building material. A circular saw works great for cross cuts through wood. Meanwhile, a table saw is practical to rip the edges of the legs. The important thing to do is make sure each side of the legs are identical in size.

You can also create a three-sided box for the legs to create a 3D effect. After cutting the extra pieces for the third side you can attach them to the main legs with wood glue or a nail gun.

Now it is time to mount the legs to the wall. A stud finder will help you locate the studs in the drywall to make sure they are mounted properly. It is extremely important that you use a leveler to make sure the mantel legs are precisely straight.

Step 3: Build the Breastplate

The breastplate is essentially the middle piece of the mantel which exists directly above the firebox, and between the two legs. However, it isn’t the actual mantel shelf (more on that later).

Now that you have the appropriate dimensions cut the breastplate to size. There are different methods for attachment depending on the type of material you’re building the mantel with. Wood is pretty self-explanatory. Tile and marble require a stronger construction adhesive since you can’t nail through harder surfaces.

After the breastplate is secured to the legs, attach it to the wall. Once again, use the leveler to make sure it’s still straight.

Step 4: Apply the Molding

The legs and breastplate of a fireplace mantel make up the skeleton of the unit. Now that you have the structure, it’s time to get down to the finer details.

You need to apply crown molding to the top of the mantel beginning at the breastplate. A circular saw will help cut the pieces of the crown molding down to size. Always cut at a 45-degree angle when working with molding or trim. Then, use a pneumatic brad nailer and wood glue to secure the molding to the breastplate and top of the column legs.

Step 5: Build the Mantel Shelf

Now for the fun part. It is time to build the mantel shelf by using a circular saw to cut it down to your desired size. The shelf will sit on top of the two legs.

If you need a stronger bond for stone we recommend using a construction adhesive. A nail gun works nicely for wood shelf mantels. Everything is starting to come together now!

Step 6: Add Your Accents

Though not mandatory some builders decide to finish off the mantel with decorative molding. The molding creates accents which is a common feature of fireplace mantels. It is completely up to you how and where you want to apply decorative molding. This is where your imagination can really run wild.

Step 7: Apply a Finish

After the molding dries you have the option of painting or staining the mantel if it’s made of wood.

Paint stain can really bring out the qualities of the wood while keeping the grain and finish of the wood. Paint will coat the grain yet some people prefer it for a more strong and powerful look.

It is a matter of a personal choice. Just make sure you invest in a heat resistant paint or stain. We also recommend you use interior grade spackle to fill in nail holes prior to finishing the wood off with varnish or paint.

Building a Fireplace Mantel is Rewarding

natural stone fireplace

Building your own fireplace mantel from scratch is a very rewarding DIY project. It’s possible to build it with the right tools and doesn’t require a ton of time or energy.

Making your own fireplace mantel will save you a ton of money and you’ll be prouder of the final result. Just take your time to make sure it’s done correctly, and always exercise caution while operating table saws and circular saws.

Chimney Inspection, Cleaning, and Repair

Your fireplace is not safe to use if you have large amount of creosote buildup inside your chimney. Creosote is a fire hazard and it’s found inside chimneys. To prevent chimney fires and creosote buildup, we recommend a chimney inspection. With a chimney inspection, you’ll prevent major problems from occurring in your fireplace and chimney.

Next, chimney cleaning is essential for keeping your home safe. We thoroughly clean your chimney so there won’t be any traces of creosote left inside your chimney. Chimney inspection also determines the integrity of the mortar joints on your chimney.

If we find structural damage in the mortar joints on your chimney then it’s time to repair it by doing some chimney tuckpointing. Altogether, a chimney inspection, cleaning, and repair is a good start. Speak to a specialist and contact us today.

Got a question?

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What We Offer

If you’re not sure if your fireplace is safe to use, it’s probably time for an inspection.
Proper maintenance begins with good old fashioned hygiene. Learn more our maintenance process here.
Whatever we find, we can fix. Find out more about our repair process here.
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