How to Build a Fireplace Surround and Mantle

We LOVE fireplaces. We love the way they anchor a room and add charm, character and architectural detail. There is nothing better than cozying up with a blanket by the fireplace on a chilly winter’s day. Just ask my youngest grandson about that! It can be 90 degrees outside and the A/C is on and he wants to turn on the fireplace and cuddle up in a blanket! If you look closely at this photo you will see that the patriotic decor is on the shelves, the fireplace is on and we are cuddled up reading a book. Yep, it’s July and he wants a fire! There is something magical about a fire. It beckons to a simpler time, gathering around the fire as a family and sharing stories.

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Let’s take a look back at what this space looked like the day we moved in. This area was the formal dining room. If you would like to see the transformation of the entire room click here.

Can you believe the transformation? Isn’t it amazing?  We certainly think so! We are thrilled with the way this turned out. It just completes the room. We did not do this along with the initial remodel. The fireplace and built-ins were done one year later. To see the complete tutorial for the built-ins, click here.

Now on with the build . . .

Tools and supplies we used:

  1. table saw or circular saw
  2. pneumatic finish nail gun
  3. wood glue
  4. 2 x 4 lumber
  5. 3/4″ 4 x 8 MDF wood panel
  6. 3 1/2″ base moulding
  7. 1 1/2″ x 1/2″ flat trim
  8. 8″ x 1″ flat moulding board
  9. crown moulding

We began by drawing out the design plan on the wall so we could visualize it.

Pro tip: Our markings on the wall were 1″ smaller than our desired design to accommodate the thickness of the drywall.

I began looking for the right gas fireplace insert, and my brilliant husband said, “why don’t we just reinstall the one that was in the den that we removed?”

I didn’t like it because of all the brass trim. I was planning on buying high heat spray paint to update it and once again my hubby, Steve found a way to just remove the brass trim, no need for paint.

We built the framework for the fireplace out of 2 x 4 lumber. You may also notice PVC pipe behind the framing. This was Steve’s idea for running cables and wiring for gaming, surround sound and cable. Once again he is the brains behind every project.

Once all the framing was complete as well as running the gas line for the fireplace it was time for the drywall.

Now when the drywall was all up, it was time to tape and mud the seams and screws.

With the taping and mudding finished we mapped out the design on the wall. You can see here the sketch of the surround and mantle areas. This helped to know exactly how to cut each piece of wood.

For the fireplace surround we used 3/4″ MDF panels. We chose MDF because it paints up beautifully and it is more economical.

We cut 2 of each piece pictured in the diagram.

  1. 53″ x 7″ (note that the bottom section of this is 6″ wide for 40 1/2″)
  2. 40 1/2″ x 6″
  3. 40 1/2″ x 9 1/2″

Assemble the surround boxes by running a bead of wood glue on the 2 sides of the 40 1/2″ x 9 1/2″ piece. Align this board so that it is flush with the 2 side panels as pictured. Using the pneumatic nail gun secure the sides. Note: the seam of the wood will be on the front of the boxes. It will be covered later by the moulding.

We next secured the 2 boxes to the wall by lining them up with the pencil lines we had made on the wall. We attached them by securing some strips of wood to the wall into the studs, then nailing the boxes to the wood strips on the sides.

Next we cut a board (72 1/2″ x 7″) that will fit on top of the 2 side pieces. Secure into place with wood glue and nails.

Cut another board (72 1/2″ x 12 1/2″).  Run a bead of glue along the bottom edge and the 2 sides and mount to the 2 side boards and the board that connects the 2 side columns. Secure with nails. Note: The seam should be on the front and it will be flush with the 2 side boards. This seam will be covered with moulding.

We then cut the board for the mantle top (74″ x 11″). To make the mantle top appear chunkier, we applied 1 1/2″ trim boards on 3 sides with a mitre cut on the 2 front corners.

Secure the mantle top in place with wood glue and brads.

Now it’s time for all of the details! Yah! This is what makes it come to life.

We used baseboard for all of the decorative craftsman/shaker details. I wanted to mimic the design of the custom shaker cabinets that are in our kitchen. Take a look at the cabinets and the moulding we used. I think it was a pretty good match.

At the base of the 2 columns we used the 8″ x 1″ moulding board, trimmed to 7″ wide. We mitered the corners and installed this with wood glue and nails first. This can be seen better in the close up picture of the column piece above.

We cut a 5 1/2″ strip from the 3/4″ MDF panel to use against the chimney wall where it meets the ceiling.  Cut the board longer than needed then hold it in place and draw lines on the back of the board where it meets the sides of the wall. Cut the boards on the marked lines and secure it in place using nails.

For all of the decorative trim we used a 3 1/2″ baseboard, mitered the corners and secured in place with wood glue and nails. Just below the top of the mantle we used a 1 1/2″ board behind the crown moulding piece. It can be seen a little better in the photo below.

On the wall above the mantel we ran 2 lengths of the baseboard with the decorative edge facing each other on each side.

The final step is to caulk all of the seams and putty in the nail holes. Once it is all prepped it is ready for paint. We had a custom color paint mixed that matched the kitchen cupboards. Quick tip: Wait to install the tile around the fireplace until the painting is finished. This will save time masking off the tile. We used a traditional and classic white hexagon tile for the surround.

We are in LOVE with the way the fireplace and built-ins turned out! Do you like it? Was this tutorial helpful? Did we leave out any details? Please drop us a comment and let us know what you think. We would love to hear from you!

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Would you like to have a tour of the entire living room? Click here!

You may be interested in this custom built-in post as well. Check out how we built  custom mudroom storage to keep everyone organized

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