How to Build a Mid-Century Modern Fireplace Mantel

September 2020

Picture of our updated livinging room

We wanted a simple, elegant, mid-century-esk fireplace mantel. A fireplace mantel is an easy project to undertake and it will drastically change the character of your room! Our challenge is that we needed a mantel larger than the common 60- and 72-inch kits. And I love an excuse to get my saws out. Here’s a before and after and some tips for the design and build adventure.

To brighten our living room, we removed a massive bookcase and shelving unit, added a window and window coverings, replaced the mantel, updated the mirror, painted the brass solid black, white-washed the rock to mute the yellow. This post will focus on the mantel.

Similar Curtains | Fun Peacock | Similar Vases | Similar Mantel | Stain

Parts List | Wood Materials for 72+ inch Mantel

  • 2 @ 1 in. x 6 in. x 8 feet, Hemlock (top, face, and sides)
  • 2 @ 1 in. x 4 in. x 6 feet, Hemlock (bottom)

Mantel Build Tips

#01 – Reduce Project Cost. I only covered the sides of the mantel to the point where it touched back to the top of the fireplace — this saved money by not running the board the length of the underside of the mantle.

#02 – Mantel Overhang. I opted for a little over an inch with a 5.5 in. top board and the 3/4 in. thick face board. Want more overhang, buy an 8- or 10-inch top board.

#03 – Tight Joints. To get that butcher-block / tight joint look make sure to run each board through your table saw or planer to remove the rounding.

#04 – Know when to Cheat. Wood filler can be your friend to fill knot holes and any gaps. I have spent more time than I care to admit researching the “perfect” product – be it putty, plastic wood, filler, and all the variants. For projects I’m staining, I use a product like Minwax Stainable Wood Filler. For projects I’m painting, Bondo Wood Filler all the way.

Tools for the Mantel Job

  • Wall Texture if the existing mantel is huge
  • Minwax Dark Walnut Stain
  • Clamps
  • Wood Glue
  • Table saw, miter saw, and jig saw.
  • Sander and sand paper options (80, 120, 240, 320 grit – or thereabouts). This pack of sanding discs was great for my Rigid 5-inch orbital sander.
  • Planer
  • Drill and Screws (to fasten the mantel hanger – I used a 2×2)
  • Eye and ear protection: Recently switched to try these DeWalt safety glasses. I also cheat and use Quick Spit or Dawn dish soap to stop any fogging.

Let us know if you have any questions or need further encouragement to take on this design and build!