How To Install Fireplace Mantel Shelf

As a homeowner looking to increase the worth of your house, you can often get confused by all the choices available on the home improvement market. Putting in a pool or sprinklers can be costly and often do not increase your home’s value as much as you would think. One answer that many people don’t think about is the possibility of a new fireplace mantel shelf.

A brick fireplace is often one of the central features in a living room, so why not spruce up one of your house’s best features. According to friends in real estate, redoing a fireplace is one of the best returns on the dollar.

In this article, you will learn how to install your mantel shelf if you have already purchased a shelf for your fireplace. Please see my review article on different fireplace mantel shelf ideas if you are still looking to buy or build your mantel shelf.

Picking a Wood Mantel Shelf

It can be dizzying when you first start browsing all of the many fireplace mantel shelves available today. The choice of your mantel shelf not only depends on your house but also on the type and size of fireplace. A good friend that’s gifted with tools never hurts either!

Finding the fireplace mantel shelf you need is often not difficult, and the average homeowner can install their own mantle shelf in an afternoon with a little hard work. The first decision you will have to make is what size mantel your fireplace will require.

The National Fire Code has a set of guidelines for fireplaces, but it is also good practice to check on your county’s particular ordinances. Look up the building inspections department under your county’s name and give them a call.

I’m sure they’ll be glad to let you know what the requirements for installation are. Otherwise, the National Fire Code requires that your mantel be 1 inch away from the edge of the firebox for every 1/8th inch that it comes out from the wall.

That means that if your mantel shelf sticks out four inches, it needs to be 32 inches above the hearth portion of the fireplace.

Easy enough? Now that you know how high your mantle shelf will have to be find a website with some different shelf selections. Take a look at each mantel’s width, and then figure out how high it will have to be according to the specs we talked about. A thin mantel can always go higher than necessary, but a wide mantel can’t go lower than recommended, so keep this in mind.

Next, measure the width of your fireplace across the top, where you will place your mantel. Most mantle shelves come in a standard size of 5-7 feet across, but a wide range of sizes are available on the internet. Figure out how wide of a mantel you need, and then factor this into your choice of the shelf.

Installing the Fireplace Mantel Shelf

Materials you will need to install fireplace mantel shelf:

  • Mantel – Depending on how your kit came, this could be all that you need. Note that we are only looking at how to attach a mantel shelf and not a full surround.
  • 2 x 4 lumber for cleats can be cut at the local hardware store
  • Two 1/2-inch-long 1/4-inch concrete screws
  • 2″ Finish Screws
  • Wood Putty if you want to fill the screw holes

The fireplace mantel shelf installation can get a little tricky, but if you have a little home improvement knowledge, installing a new mantel is fun and gives you a good sense of accomplishment. The first thing that you will need is called a “cleat.”

This is a board that we will cut to fit snugly on the back inside of the shelf, where it is hollow. This is just a piece of wood that is cut from a piece of lumber and will hold your mantel up.

Measure the width of the inside of the back of the mantel and then measure the depth. Subtract two inches from the interior width, and this will be the length of the piece of wood you need.

Then measure the depth of the inside of the mantel, which will determine the cleat’s width. Take these measurements to your local home improvement retailer, and they can quickly cut you a piece to your exact measurements.

Now that you have your cleat, you will want to attach it to your wall. Double-check the height your mantel will need to be placed at and mark this height on the brick where the bottom of the cleat will go. Take the level and line it up against this line, moving it slightly until it is level.

Mark the bottom line where you will line up the cleat. Next, mark three holes for your screws on your piece of wood for the cleat: one toward the left, one in the middle, and one on the right.

Once you have all your spaces marked, line up the cleat and drill through the wood to your brick with the concrete screws.

After you have all three screws in you, have successfully installed your cleat. Slide the mantel onto the cleat and push it back until it is flat against the wall.

Finish the fireplace mantel shelf installation project by placing 2″ finishing screws every twelve inches along the back of the mantel, drilling down into the center of the cleat. Congratulations! You just installed your brand new brick fireplace mantel shelf!

Mas Broto

Written by: Mas Broto

Mas Broto is a small business owner with 30 years experience in the real estate industry. He is the founder and editor of, the most comprehensive free home improvement website on the planet!