Here’s how we built a floating mantle above our electric fireplace in our living room. I’ve gone ahead and included the dimensions specific to our specific project, so feel free to alter them as needed based upon what size mantle you’ll need.
Supplies & Materials
- Face Plate: (1) 1×4 cut to 64.5″ length
- Top and Bottom: (2) 1×6 cut to 63″ length
- Side Panels: (2) 1×4 cut to 11″ length
- Back Plate: (1) 1×4, ripped to 2″ and then cut to 63″ in length
- Braces: (4) 2×4 cut to 4″ in length
- (1) box 1-inch black construction screws
Build the Mantle
First, you’ll want to determine which of your pieces you want to face outward and therefore be seen. Then mark the back side so you’ll know which side to drill the pocket holes.
After you’ve cut all your pieces to length, begin drilling pocket holes on the inside pieces of your mantle.
Take your top and bottom pieces and drill pocket holes along the long side on both boards. These will be screwed to the face plate of the mantle. Be sure to check for square when attaching these pieces together. Use clamps if needed.
Take your top piece, line it up, and then screw it to the face plate. We opted to use wood glue along with screws to ensure a stronger bond.
Now take your two side pieces and drill a pocket hole on one end of each board. We’ll use these to attach the side pieces to the face plate.
Next, attach the top and bottom pieces.
At this point you should have the shell of the mantle complete. Wipe any excess glue off and then sand the mantle really well before staining. We opted to use Minwax’s Early American stain to match our wooden hearth.
Build the Support Brace
To build the back plate that will hold the mantle in place take the 1×4 that’s been ripped to 2″ and attach your (4) 2×4 braces. We chose to attach the first support brace in 5.5″ from the end and then attached the second one 12″ from that one and repeated these measurements for the other end of the board. These measurements may differ based upon the total length of your floating mantle piece.
Make sure the 2×4’s are flush with the top of the board. You’ll want the top of the mantle shell to sit directly on top of these braces in the same way a floating shelf would.
Attach Mantle to Fireplace
Now it’s time to attach the back support brace to the fireplace wall. At this point your frame should be encased in plywood. We attached our shiplap AFTER installing the floating mantle.
When we built our frame to hold our electric fireplace we made sure to include a 2×4 stud at 53″ from the ground to serve as the support for our mantle.
Attach the back plate to this stud, ensuring it is level.
At this point, you can either simply slide the floating mantle shell over the support brace and use two screws on the side plates to screw them to the frame or, alternatively, use (4) screws on the top and (4) screws on the bottom along with the (2) screws on the side.
We opted for the latter because we wanted to ensure the floating mantle would not budge, given the fact that we have two small children who like to hang off things. 🙂
If you’re wanting to secure the mantle with the top and bottom attachment like we did you’ll need to pre-drill (4) holes on the top, 1/4″ in from the edge of the board that sits flush with the fireplace. Countersink screws when attaching the mantle to the backplate. This way once the shiplap is installed the screws are hidden from view.
We chose to run a small bead of caulk along the seams where the mantle meets the shiplap. You can use painter’s tape to ensure you get a really smooth line when caulking.