An Easy DIY Mantel and Overmantel Project using Inexpensive Materials

In November, I shared our DIY Fireplace Makeover plans. It’s finished and ready for its close-up. While this project is based on our specific fireplace situation (height, width, depth, and paneling), you can easily customize it for your mantel. Below I’ll walk you through what I did to complete this easy DIY mantel and overmantel project using inexpensive materials.

Here’s a reminder of where we started. The original mantel was narrow, short (7″ x 46″), and uninviting.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - the original mantel

Step 1: Choose a Design for the Mantel and Overmantel

Start by choosing a design that fits your style and the era of your home. If you don’t know your style, you can turn to Pinterest for help and LOTS of inspiration.

Our original overmantel design was Farmhouse. It was nice, but didn’t blend with our Colonial-style home. So, after we regrouped from this design mishap, we landed on a new design that better fit our home’s architecture; eight well-proportioned panels lined with trim molding (as seen in the graphic below.)

graphic of the design we selected

Step 2: Build a Box to Add Height to the Mantel

To provide much-needed height (and presence), as well as support for the mantel shelf, I built a 3.5″ tall rectangular box that I attached to the original mantel. I constructed the box ¼” smaller than the original mantel shelf to accommodate decorative trim molding to camouflage where the old and new mantel meet (see photos below).

When building your box, it’s imperative to get measurements in several places because walls are rarely square. I found this out the hard way; our builder used scrap wood to construct the original mantel, and it isn’t square. Because I didn’t double and triple check the measurements along the entire mantel, I had to disassemble the first box, then rebuild it.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - box to support mantel shelf
The mantle box with ¼ trim molding at the base.
close-up of box to support mantel shelf
Close-up of mantel box and trim molding; you can see in the corner how the original mantel is not square.
An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - showing the out-of- square original mantel
Close-up of the holes left by the brad nailer; I used a nail set to sink raised brads, then filled holes with wood putty.

A center cross piece will provide an additional attachment for the mantel shelf.

showing cross piece for additional attachment for mantel shelf

Step 3: Add Mantel Shelf

Having a mantel shelf deep enough for vases, plants, candles, and Christmas stockings was a must. So I went with the 1″ x 10″ x 10 ft Premium Kiln-Dried Square Edge Whitewood Common Board (which in reality is 9.25 inches wide, not 10″) and had the pros at Home Depot cut the board to length while I waited.

The actual depth of a 10″ board is 9.25″, which is perfect for our new mantel.

I attached the mantel shelf with a few brads to hold it in place while I drilled pilot holes for the wood screws. I also used a countersink tool to make a divot in the wood, so the screw heads are below the surface (to be filled in later with wood putty or spackle).

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - wood putty covering screw

As is typical with any project, we changed our minds along the way regarding finishing particulars. One such detail is the fireplace legs (the vertical pieces below the mantel that appear to be supporting the mantel but are merely decorative), where we decided to add ¼”x 1½” hobby board frames to each leg. This trim detail will tie into the panels on the overmantel.

hobby board added to fireplace "legs"

Step 4: Construct the Overmantel

Prep the Overmantel Wall (only necessary if you have grooved paneling)

In addition to the short mantel, we have paneling on the same wall. Paneling was a popular builder choice in our neighborhood in the 1970s. We decided to fill in the paneling grooves with drywall mud (aka joint compound). Check out the drywall mud stripes on the wall in the photo below.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - drywall mud stripes on the wall above the mantel

Because drywall mud shrinks into the paneling grooves as it dries, filling-in the paneling grooves took several layers of drywall mud.

I started the process early in the day; apply the drywall mud, wait for it to cure/dry, sand, vacuum, and repeat. I worked on other parts of the project while the drywall mud dried. The entire process required FOUR coats of drywall mud until the wall above the mantel was finally smooth and groove-free.

I promise I didn’t make up the word overmantel. I wasn’t quite sure what to call the area over the mantel, so I Googled it, then felt silly as the name is so, well, obvious.

Build a frame

Based on your design dimensions, build a large frame between the mantel and the ceiling or crown moulding, in our case. We used ¼” x 2½” hobby board for the entire overmantel.

This step is pretty straightforward. Measure and cut the hobby boards to size. While checking for level, attach the boards with a brad nailer.

We used a brad nailer because we were attaching hobby boards to wood paneling. However, if dealing with sheetrock, you might consider using construction adhesive or wood glue, as well as brads, to attach the overmantel boards.

Be sure to use a level while attaching each of the vertical boards; it’s imperative to keep your frame perfectly square. After all, you’re going to see this Every. Single. Day. And, I promise you won’t be able to un-see any bit of it that isn’t level or square.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - build a box to frame out the overmantel area
I started by building a frame above the mantel.
our dog "helping" out
It’s always good to have a helper.

Construct Columns

To create eight well-proportioned panels, I began by making four equally-spaced columns. Measure to find the center of the frame and mark it on the upper and lower frame boards. Then center the vertical hobby board on the marks and attach it to the wall (using a level and the brad nailer.) See below.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - centering boards on overmantel
Centering the middle vertical board.

Repeat this process on the left and right sides of the frame to create four equal columns.

centering boards on overmantel
Centering the middle vertical board on the right side of the overmantel.
An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - columns above mantel
Four equally spaced columns.

Turn Columns into Panels

Measure the distance between the top and bottom boards to find the center point measurement and make a small pencil mark on each vertical board. Measure the distance between each vertical and cut the hobby boards. Next, center the horizontal hobby boards on the center marks and attach using the brad nailer and a level. Your level is your best friend here because those horizontal boards have to be level.

making the overmantel panels

Add Trim Moulding

As a result of wanting the overmantel to have that old paneled library look, we lined each panel with trim moulding.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - completed trim on overmantel
I got a bit carried away during this phase and failed to take any photos while installing the trim moulding.

Each panel in the overmantel, as well as the legs of the mantel, is lined with the smallest moulding we could find at Home Depot; specifically 5/16″ x 7/8″ solid Pine Wall and Trim Moulding.

Cut the trim moulding at a 45° angle for nice tight corners. A warning about the pine trim moulding – it’s very soft and frays a bit. Be sure you use a fine-tooth blade for trim to reduce the splintering; I did not use a fine-tooth saw blade and went through a lot of moulding as a result.

Finish it up!

I used a nailset and hammer to drive the brads below the wood surface, then filled each brad and screw hole with wood putty or spackle. I also filled every gap where the hobby boards meet. After letting the spackle dry overnight, I sanded, cleaned up with the Shop-Vac, and started priming (two coats). Then the pièce de résistance, paint; two coats of Behr Ultra Paint and Primer in Graphic Charcoal.

Primed overmantel. Time to paint!


An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - completed mantel and overantel
close-up angle of mantel and legs
A new hearth is coming soon…
An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - close-up angle of fireplace legs and mantel
Angled photo of mantel and part of overmantel
Now the mantel is deep enough for large decor pieces!

This easy DIY mantel and overmantel project took two weeks to complete (working mostly evenings and weekends) and it coast less than $150! The finished product is such a dramatic improvement that I wish I’d tackled it years ago! The deep Graphic Charcoal paint is striking. Plus, depending on the time of day, the color changes from light gray to charcoal (and sometimes dark blue) to black in the evening. It’s a total chameleon! Our fireplace mantel and overmantel are now a stunning focal point, rather than a bland, builder-grade afterthought.

Mantel and Overmantel Supplies:


  • Compound Miter Saw (you can also use a miter box and hand saw)
  • measuring tape and level
  • drywall knife (optional, not necessary if you don’t have paneling)
  • ShopVac with sanding filter and drywall dust bag & microfiber cloth
  • pencil and speed square
  • ladder
  • brad nailer and ½” brads
  • nailset and hammer

P.S. The dog likes it too. I may have to clean the inside of the fireplace to create a little doggy hideaway for her.

An Easy DIY Mantel and Overmantel Project using Inexpensive Materials - our dog sleeping on the fireplace hearth

Stay tuned for my next project, how to clean and paint your brick fireplace surround.

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