Finishing the Fireplace Drywall: Corner Bead, Crown Molding, and a Long Overdue Comeback

After a much-needed two-week break, I am back and more fired up than ever to finish this fireplace. Yes, I missed my original Christmas deadline, largely thanks to a total rebuild of one side of this niche a few episodes back, but rest is exactly what I needed to come back with real momentum. In this post, I am walking through how I finished the drywall, tackled the corner bead, started the crown molding for the mantle, and finally started seeing the light at the end of this ten-month tunnel.

If you remember the checklist I made at the very start of tearing down the old built-in, it went something like: smash it, regret my choices, then build something really cool. I have been stuck between steps two and three for a while now, but this episode is where things finally started moving into step three for real.

Finishing the Drywall

Priority number one for this session was finishing the drywall that had been sitting partially done for a while. I started with the front pieces of the niche, which was honestly the part stressing me out the most. My process was to clamp the drywall piece into position, screw it in, then score it from behind and snap it off rather than trying to cut it to an exact shape ahead of time. It sounds backwards, but it gave me a lot more control over getting the fit right.

For driving screws into position and leveling everything as I went, I used my Athena Drill by Aleah, which I designed specifically with women in mind. It made quick work of getting that first screw in and using it as a reference point to level the rest of the piece from there.

For the second arch, I repeated the same method: cut the piece, clamp it into place, then cut it from behind using an oscillating tool, since that approach worked the best the first time around. The key here was making small, strategic cuts around the arch shape so the cutout piece would not drop and break before I could actually use it, the same lesson I learned the hard way in an earlier episode.

By the end of that session, I had run low on drywall and needed to head out for a half sheet to finish the last section. For the flat, interior back sections that will eventually be covered in stone, I switched to dura rock instead of standard drywall, since it holds up better under stone and I figured I could combine both materials without any issue once the mantle covers the seam.

The Shopping Run

Back at the store, I discovered they no longer carry half sheets of drywall, only full four-by-eight sheets priced higher per square foot when bought as partial pieces. I ended up buying several smaller cut sheets instead of a full one, since I did not want to store, manage, or lift an entire sheet of drywall for the small amount I actually needed. It was not the most cost-effective option per square foot, but it was the more practical one for my situation.

While I was there, I also picked up materials for the mantle, since I figured I might as well grab everything in one trip. I chose a five and a quarter inch crown molding profile for the interior of the fireplace opening, going with a simpler look rather than anything overly ornate. Each piece comes in nine-foot lengths, but since I did not need the full length, I cut them down to roughly six to six and a half feet to give myself some wiggle room for adjustments.

For the mantle build itself, I made the call to use primed pine board instead of cutting my own pieces out of MDF sheets on the table saw. It would have technically been cheaper to cut my own, but the primed board meant fewer cuts, less labor, and one less finishing step since it already came primed. After ten months on this project, I decided that the extra roughly one hundred dollars was money well spent to save time and effort at this stage. No regrets there.

Taping, Mudding, and Corner Bead

The next work session was all about finishing details. I started with the horizontal seams first, letting those set before moving on to corner bead, since doing corner bead too early would have meant redoing work later. I used a self-adhesive mesh tape rather than traditional paper tape since it is what I had on hand, applying it with a putty knife on flat seams and a razor blade for cleaner outer corner cuts.

For corner bead, I started with the bendable version around the arches, since that section is small enough that there is not much room to feather out mud gradually the way you would on a larger flat wall. Rather than buying a dedicated crown stapler for such a small area, I made do with a regular stapler, which worked well enough for this application.

Once the outside corners were done, I moved on to getting the dura rock installed and taped along the seams before wrapping up for the episode. Since cutting cement board kicks up a lot more dust and debris than regular drywall, I made sure to wear a respirator mask along with my Aleah safety glasses before making any cuts. Cement board dust is not something you want in your lungs or your eyes, and having the right protective gear on made that part of the job a lot less stressful.

Where Things Stand

We did not get quite as far as I had hoped, which at this point feels like the theme of this entire build. Every step seems to take longer than I plan for. That said, the progress made in this session was real and visible, and the next phase moves into what I consider the fun part: finishing the drywall and starting to actually build out the fireplace mantle itself.

Ten months into this project, seeing corner bead go up and crown molding pieces getting cut for the mantle finally feels like the light at the end of the tunnel I have been waiting for.

Watch the Full Episode

There is a lot more detail in the actual footage than I can fully capture here, including the exact technique for cutting drywall from behind without cracking the arch pieces, and the full process of taping and mudding those tricky small corners. If you want to see it all in real time, watch the complete episode on my YouTube channel, Aleah DIY. It includes everything from this post plus the parts that only really make sense when you see them happen.

Frequently Asked Questions

Why cut the drywall arch shape from behind instead of pre-cutting it? 

Clamping the piece into place first and cutting it from behind with an oscillating tool gives much more control over the final fit. It reduces the risk of the arch shape dropping and breaking before it is secured, which is a real risk if you try to pre-cut the exact shape ahead of time.

What is the right order for drywall finishing: horizontal seams, corner bead, or mud first?

 Horizontal seams should be taped and allowed to dry first. Corner bead comes after that, followed by mudding. Doing corner bead too early can mean redoing sections once the seam mud goes on, so following that order saves rework.

Do I need a full sheet of drywall for a small project like this? 

Not necessarily. If half sheets are not available, smaller cut sheets can work, even if they cost slightly more per square foot. For a small job, avoiding the storage and handling of a full sheet can be worth the small price difference.

Is it worth paying more for primed mantle board instead of cutting my own from MDF?

 It depends on how much you value your time. Primed board costs more upfront but requires fewer cuts and skips a priming step entirely. On a long project where labor time matters more than material cost, that convenience can be worth the extra expense.

What protective gear should I wear when cutting cement board like DuraRock?

 A proper respirator mask and eye protection are both important, since cement board produces much finer, more irritating dust than standard drywall. Wearing certified Aleah safety glasses alongside a dust mask helps protect both your lungs and your eyes during that step.