DIY Floating Fireplace Mantel / Live Edge Shelf

If there is one thing I’m really good at, it’s hoarding lumber. I have had a gorgeous live edge piece of walnut in my shop for months and had no clue what to do with it… until now! In just a few short steps I was recently able to transform a walnut slab into a DIY floating fireplace mantel (and was able to do it one weekend)! Not in the market for a mantle? You can follow these same steps to create a shelf as well! Here’s how!

How To Build A Floating Fireplace Mantle

This post is sponsored by The Home Depot and is part of the ProSpective program. It contains affiliate links. For my full disclosure & sponsorship policy, click here.

Want to see this project in action? Check it out on my YouTube channel and please subscribe!

This project was a pretty cool one for me because I was actually able to make it happen for my boss at my full time job! Him and his wife recently updated their fireplace and added a beautiful ship lap accent wall, but were in need of a mantle to ground the space. I legit could not have thought of a better piece of lumber to make this happen (and I was able to do it in one weekend)!

What I Used:

Tools
Circular Saw & Track *
Drill
Surface Planer *
Dremel Versa Scrubbing Kit
(w/ Scrubbing Detail Brush & Kitchen Scour Pads)
Sander

* These are tools that are optional for this build. If you do not have these tools available to you, please check out my DIY Resin River Table project, which specializes in working with a live edge slab in a small space with limited tools.

Materials
Live Edge Walnut Slab
Floating Shelf Bracket & Template
Walrus Oil Furniture Finish
Fasteners *

* The type of fastener you use for your particular project will vary based on where you are hanging your mantle or shelf. Please do your research on which particular fastener you will need for your shelf before hanging.

The Steps:

1. First thing I had to do for this slab was cut off one side of the live edge to create a straight edge that would sit flush with the fireplace mantle. To determine how deep of a mantle I needed, I placed the bracket I was using on top of the slab and then created a reference line. My bracket was 6″ deep, so I cut my slab to 7″ deep using my circular saw and a track.

2. To save myself some time on sanding, I ran the slab through my surface planer a few times. But, this was an optional step!

3. Next, I cleaned up the live edge using a Dremel Versa Power Scrubber with a scrubbing brush and pad. This is a tool that is usually used for household cleaning, but it was perfect for this project! It allowed me to gently remove any dirt and debris using soft bristle brushes and scrubbing pads without taking away the character of the wood.

4. After cleaning the edges, I cut my slab down to it’s final size.

5. Next, I marked and drilled the openings in the back of my slab for the shelving bracket to go. The bracket I bought also came with an optional installation kit that I purchased to make this process easier. Spoiler alert: I’m obsessed.

6. I wanted to recess the bracket a bit, so I used my router to create a groove in the back of the slab for the bracket to sit.

7. Last step in the build process was to sand to 400 grit and finish the slab with Walrus Oil furniture finish.

8. All that was left was to install the bracket to his fireplace and then slide the mantle onto the bracket!

P.S. It’s best to do research on the appropriate type of fastener for installing your particular mantle. Fireplace materials and structures differ greatly!

Now this beautiful slab has a home and a function and I couldn’t be happier!

The walnut slab totally fits the cozy, rustic feel of my boss’ fireplace and home — they are so happy with how it turned out and that makes me so happy too!