Building a Fireplace Mantle and Surround

It’s Tuesday, which means I’m back with updates on our fireplace progress. If you’ve been following on Insta Stories, then you’ve already gotten plenty of sneak peeks as we’ve worked on this space (and maybe even saw the big reveal!). Bridget and I are always working on blog posts a few weeks out, but you can always get behind-the-scenes looks at our projects in real time if you follow us on Instagram.Fireplace makeover before grout

But anyway, let’s get to today’s topic…building a fireplace mantle and wood surround. Last we chatted, we had finished adding the marble subway tile to the hearth and sides of the fireplace. I must admit…it looks damn good. I’m very proud of our tiling work, as we’ve improved 100000x since last year’s bathroom fiasco. It just goes to show that you can only get better at DIY skills with practice.

As for building a fireplace mantle, that is something we’ve never ever done before. Yes, I’ve used the miter saw for cuts on simple woodworking projects (like this board & batten, these bifold doors, this wood wall), but I haven’t ever done a woodworking project of this size. And neither had Finn. Until now.

Drawing up Plans for the Fireplace Mantle

Fireplace mantle plans

The first step was figuring out what the heck we even wanted it to look like. We looked at lots of inspiration photos (like the ones in this post), discussing what we did and didn’t like about the space. We also took into account our unique situation…with an oddly shaped fireplace that wraps around on the right side. After tons of measuring, researching, and drawing…here’s what we landed on.Fireplace mantle blueprints

This is Finn’s drawing and I’m sure he is going to be horrified that I’m putting it on the internet to see, but it helps to understand how we got started (and look at his cute little fire burning in there!). Because our drywall was severely damaged, we wanted to start with a base of MDF on all sides of the fireplace. That would act as our background for all of the decorative trim and molding. We’d then do baseboard (to match the rest of our house) on the bottom, molding underneath the fireplace top, and strips of lattice to give it a craftsman style look!

Armed with our plan (and tons of measurements), we made a trip to Lowe’s to pick up all of our supplies.

Woodworking Supply ListShopping for supplies at Lowe's

Before I get to the supply list, let me paint you a picture of Finn and me loading up our tiny car with all of our wood supplies. It was freezing out, we both couldn’t feel our hands, and we were forcing these heavy ass boards through the passenger seat into the back of our car. Thank goodness for the little opener in the back seat that goes through to the trunk. That was our saving grace to fit the 8-foot pieces into our car. An SUV is on our shopping list this spring and this project just might have given us the kick in the pants to get around to buying that new car!

Anyways, here’s what we got for this portion of the project.

  • MDF (it comes in 4×8 sheets, 3/4 inch thickness; We only needed 1 sheet for our entire fireplace but had them cut it at the store so we could fit it in our car)
  • Birch Plywood (4×8 sheet; 3/4 inch thickness)
  • Baseboard
  • Shoe Molding
  • Lattice Molding
  • Pine Bed Molding
  • Wood Edging
  • Sanding Sponge
  • Liquid Nails
  • Caulk Gun
  • Clamps
  • Safety Gear
  • Hole Saw

Tools Needed

Attaching the MDFMeasuring MDF for the fireplace

With our plan in place and all of our supplies on hand, it was FINALLY time to get this project moving. Our first order of business was to connect the pieces of MDF to the face of the fireplace. That meant lots of measuring and re-measuring to make sure everything was perfect before cutting.Using a circular saw to cut MDF

Because the boards are so wide, you can’t use a miter saw to cut them. Instead, we purchased a new tool…a circular saw! I’m not gonna lie, this little thing freaked me out at first so I monitored Finn as he made those first few cuts. Because we don’t have a garage or backyard to work in, we had to make due in our kitchen. It makes a HUGE MESS (holy moly dust), but we really don’t have any other way to do projects and we’ve gotten great at cleaning up quickly.

Using a miter saw to cut woodWe would simply clamp the wood to the island and then make cuts on the ends (making sure the blade was nowhere near the edge of the countertop). Finn got the hang of this “scary” tool quickly and was a pro with it by the end of the day. Eye protection is a must (and throw on a face mask and earplugs if you have them. It’s loud and oh-so-dusty!). Using liquid nails to attach MDF

We used a combination of liquid nails and the nail gun to secure the boards directly to the drywall. Nail gun

Between those two, our boards aren’t going anywhere!MDF on the face of the fireplace

With our first piece on, we moved onto the right side of the fireplace. We left a 3/4 overhang on the front piece, so the front lip of the side piece wouldn’t be shown. For this piece, we also had to take into account the round fireplace starter. Hole saw on drill

A hole saw made that job super easy. We measured where to make the hole and then slowly (yet firmly) used the hole saw on my drill to make the hole. Hole in a piece of MDF

With our hole made, it was time to attach piece #2. Lattice on back of MDF

In order to make a true 90-degree angle with the front piece, we had to butt the top of the right side out a bit (because our walls aren’t straight, insert eye roll here). We just used pieces of lattice as wood shims to thicken up the top part a bit. It worked like a charm. 2 pieces of mdf on the fireplace

The steps were the same for the other pieces. finn adding mdf to the fireplace surround

Measure carefully, cut carefully, and attach with liquid nails and the nail gun. Adding mdf to a fireplace surround

Making a Plywood Top

Fireplace surround with MDF

With our MDF in place, it was time for us to focus on the top. As much as we wanted to do a thick slab of wood on top, our unique fireplace layout made that a challenge. We needed a board at least 6 feet long and 2 feet deep and we couldn’t find any wood sold that way. A custom wood top would have been big bucks, so we decided to improvise with plywood. Cutting plywood with a circular saw

We bought a large slab of birch plywood to make our top in the L-shape we needed. Because we wanted our edge to be perfectly straight, we used a piece of MDF on top as a straight edge for the circular saw. I highly recommend doing this (way easier than freehanding it with the saw).

L-shaped plywood

I’m not going to lie, it took us a few hours to carefully measure and cut the plywood to fit the top L of our fireplace. But in the end, our cut piece fit perfectly (I was crossing all of my fingers and toes as we placed it up there!).

Upgrading the Fireplace MantleWood edging

Obviously, plywood isn’t the most luxurious piece of wood you can use for a project. Inexpensive, yes. Good looking, not so much. But I knew I could make it look better with a couple of tricks. First, we added wood edging to the exposed edges of the plywood. I first used this product on our guest room fauxdenza and was amazed by it!iron on wood edging to plywoodYou simply iron the wood edging onto the sides of the plywood and the heat helps it adhere. Once it’s on there securely, you sand away the excess and it looks sooooo good! Finn with fireplace supplies

Shoe molding to hide gaps on fireplace woodworkingWe also added shoe molding to the wall on the back end of the plywood. This ended up hiding some ugly spots on the wall, and it added a decorative element to the top of the plywood. Molding below helped jazz up the thin plywood and make it look meatier! For this, we used pine bed molding directly under the lip of the plywood. We attached the trim just as we did everything else…with liquid nails and a nail gun.

Installing Baseboard & Decorative Lattice

With the top portion done, we turned to the floor.

Bridget shared a comprehensive baseboard tutorial in this post a few years back. Adding baseboard and shoe to a fireplaceWe followed her guidelines and tips and were able to add the baseboard and shoe pretty quickly. It’s just a lot of measuring and cutting (and plenty of brain farts as you figure out which way to turn the saw to make the angled cuts). We left the decorative lattice for last because we wanted it to fit snugly between the molding up top and the baseboard on the bottom. We also weren’t totally sure what “design” we wanted to do on the front. Fireplace mantle woodworking

After some back and forth, we ended up just doing vertical pieces of lattice on the sides and front, with a few horizontal strips between.

Here she is in all of her glory! Doesn’t the faux fireplace mantle look amazing? We were suuuuper proud of ourselves. It’s crazy how a bit of trim and lattice can really jazz up plain ol’ MDF.

Fireplace Makeover – What Now?

We are in the home stretch! I’m planning to caulk, prime, and paint this bad boy and then the reveal is coming at you next Tuesday! I can’t wait to share the side-by-side pictures of this transformation. It certainly has come a long way…

Fireplace Makeover Posts

Casey