How to Build a Faux Wood Beam Mantel

April 26, 2019

Hi! I'm Nicole

Fearless DIY. Sharing building project tutorials and interior design tips. Let’s build something beautiful together. For more projects, design tips and behind the scenes, follow me @designtobuild.nicole

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Fireplace Makeover Phase one: How to build a faux wood beam mantel and make your fireplace the statement piece it should be!

Do you have an old dated fireplace in need of some modernization? We bought our home 12 years ago and I have never been a fan of our fireplace, until this year….AFTER I completed the fireplace makeover (which I shared a couple weeks ago here). The first step to this makeover, was replacing the boring, thin builder’s-grade mantle with a chunky faux wood beam mantel. And I’m here today to show you how I did it!

But first here’s a quick “before” look…

fireplace makeover before

And here’s what it looks like now. Isn’t the transformation amazing?!!

fireplace makeover reveal

And now let’s jump into phase one of this tutorial. (Be sure to check back for Phase 2 and 3 over the next couple weeks)…

How to Build a Faux Wood Beam Mantel:

Materials Needed:


Flathead screw driver


Box cutter

1×4’s (amount needed is dependent upon the project)

2×4’s (amount needed is dependent upon the project)

1×6’s (amount needed is dependent upon the project)

3/4″ plywood (I needed two 4×8 sheets)

2-1/2″ pocket hole screws

1-1/2 finishing screws

Wood stain (Jacobean by MinWax is what I used)


The first step is to get rid of your old mantel. The easiest way to do this is with these four tools….

tools to remove mantle

First, you’ll want to use your box cutter and cut the caulking between the mantel and the rest of the fireplace. Anywhere your mantel is attached (i.e. wall, etc), run a cut with your box cutter…

mantel with boxcutter cut

Now you’re ready to shimmy your crowbar and flat head screwdriver in between the mantel and fireplace. The easiest way to do this is to start with your flat head–using a hammer, drive your flathead into the cut you made with the box cutter. This will open up enough space to then wedge your crowbar in there, allowing you to work the crowbar up and down loosening the mantel from the fireplace….

crowbar and flathead in between mantel and fireplace

If you’re lucky your mantel will come off with little muscle power. I wasn’t that lucky. 🙁 It definitely took some work.

removing mantel from fireplace

But finally it came off…

mantel removed and ready for faux wood beam mantel

I personally didn’t want the trim around the bottom, so I ended up removing that too. And added my own trim, using 1×4’s…

mantel removed and trim added


Now you’re ready to build the cleat that will hold your faux wood beam mantel.

First measure how long you want your mantel to be, then cut a 2×4 to that length. This will be your cleat support.

Next, determine how wide you want your mantel to be. How far do you want it to stick out from the wall?

You’ll then cut 2×4’s to get you to that width. Be sure to keep in mind the width of the 2×4 you cut for the cleat support. Hopefully the picture below will help make this clear. For example, I wanted my mantel to come about 10 inches out from the wall. So, I first took into account the 1.5 inches for my cleat support (2×4) and therefore cut my cleats 8.5 inches–totaling 10 inches….

cleat for faux wood beam mantel

To attach the cleats to the cleat support, you’ll need to drill 1-1/2″ pocket holes into one end of each cleat. And then attach using 2-1/2″ pocket hole screws. I spaced my cleats out about 10 inches apart…

cleat for faux wood beam mantel

Note: If you have an outlet (like I have), you’ll need to make sure the length of your cleat support doesn’t cover the outlet. You may need to build separate cleats (one on each side of the outlet-like I did above)….

cleat bordering wall outlet

Now you’re ready to attach your cleat to the wall using 2-1/2″ screws. Make sure you are attaching your screws into studs. And it’s a good idea to use a level to make sure your cleat is straight….

level on cleat to ensure its straight


The mantel is removed, the cleat is attached and now we’re ready to actually build the faux wood beam mantel.

Using 3/4″ plywood, cut your top and bottom boards to the length and width of your cleat you built and attached above….

Plywood for faux wood beam mantel

The board above is my top board of my faux wood beam mantel. As you can see, I made a cut-out to stuff all of my cords (TV, speaker, Apple TV, etc) down into. A great way to hide all of that unsightly mess. It’ll look like this…

cords hidden in faux wood beam mantel

Next cut your side boards. Rather than using plywood for the side and front boards, I used 1×6’s. The 1×6’s give a more authentic wood look for the areas you’re actually going to see.

Attach your side boards to the bottom board using wood glue and 1-1/2″ screws (These are my all-time favorite screws to use in any project)….(Affiliate Link)….

side board of faux beam

both sideboards of faux beam

Then attach your top board….

faux wood beam mantel built

Cut your front board to size and attach it…

front added to faux beam


Now that you have the faux wood beam built, you’re ready to attach it to your cleat.

This is where mine got a little tricky and required some math. I knew this issue was coming, but decided to face it once I got to it. My beam would only slide over the cleat so far before it hit the molding and columns of the fireplace….

faux wood beam mantel hitting fireplace

(Sorry for the blurriness of the above picture–that’s really bad 🙁  ) Basically, I had to measure how much the fireplace was blocking the bottom of my faux beam and cut those spaces out….

faux beam post cutout

With some math and playing around with it, I finally got it to work….

newly built mantle for fireplace makeover

Please don’t let this scare you…If I can do all that math and work through this snag, you can too! Math is, by far, my weakest subject!! You’ve got this!!!

Once your faux wood beam is in place, you’re ready to attach it to the cleat. Using 1-1/2 screws, attach the beam to the top, sides and front of the cleat.

Fill in all of your nail holes and she’s ready for stain. I chose Jacobean by MinWax for mine (affiliate link)

fireplace makeover with faux wood beam

Be sure to PIN THIS tutorial to your Pinterest boards…

before and after of a fireplace makeover

Be sure to check back next week for phase two of the fireplace makeover–How to build a hearth.

Until next time,

Happy Building, Friend!!

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