This project was built and designed by Jonny from Jonny Builds. It’s a bold fireplace renovation that combines industrial blackened steel with a floating live-edge walnut mantel for a striking modern upgrade.
The project takes an outdated tile fireplace and transforms it into a statement feature. With careful planning, smart material choices, and clean execution, Jonny shows how this kind of home update is possible for DIYers with the right tools and patience.
Watch the full video and subscribe to Jonny’s channel:
Removing the Old Fireplace Surround
The original fireplace had a dated tile surround and a large, oversized mantle. Jonny began by removing all of it, starting with the tiles using a rotary hammer drill.
This tool made demolition fast and easy, even though it caused some drywall damage. Since new cement board would replace it, that wasn’t an issue.
The mantle was removed by prying and breaking it apart. Jonny also took off the fireplace’s glass doors but ultimately decided not to reinstall them.
Installing Cement Board Around the Fireplace
Cement board was chosen to replace the drywall around the firebox. It handles heat better and provides a strong, flat surface for mounting steel panels.
Each board was scored with a utility knife, snapped cleanly, and then trimmed along the mesh backing. This method ensured accurate cuts and a snug fit.
The panels were fastened to the framing and aligned carefully. With the base layer complete, the wall was ready to accept the new design materials.
Fabricating and Blackening the Steel Panels
Jonny used 14-gauge steel plate for the new fireplace surround. The panels were cut into manageable sections for easier installation and a modular look.
Using a circular saw with a metal-cutting blade made cleaner cuts than a grinder. This helped produce tight, consistent edges that aligned well on the wall.
To achieve the deep black finish, Jonny removed the mill scale using muriatic acid mixed with water. The metal was then neutralized and treated with a blackening solution.
The patina developed quickly, creating a dark, textured finish. After that, the steel was sealed with paste wax to lock in the color and add subtle sheen.
Mounting the Steel to the Wall
Each panel was installed using construction adhesive and clamps to hold it in place. The largest top panel was placed first to act as a level reference for the others.
Some steel panels overlapped parts of the firebox to hide existing framing and fire curtain edges. This created a clean transition and a modern appearance.
Where needed, Jonny drilled into the sidewalls to pull panels in tighter using clamps. He also made a hidden access panel with rare earth magnets for lighting the pilot light.
Addressing Functional Details
The fireplace’s gas key and light switch were still necessary. Jonny measured and marked these spots carefully before cutting holes into the steel panels.
A custom switch plate was fabricated from a matching piece of steel. It blended seamlessly with the new surround and kept the look cohesive.
This attention to detail made sure the fireplace remained fully functional without sacrificing style. Everything worked as it should while enhancing the visual impact.
Creating the Walnut Mantel
To balance the steel’s cool tone, Jonny installed a live-edge walnut mantel. He sourced the slab locally and chose it for its natural shape and strong grain pattern.
Shelf pins were embedded in the wall to support the mantel. A laser level ensured they were aligned precisely across the width of the fireplace.
Jonny drilled into the mantel to accept the pins, then routed mortises in the back so it sat flush. Once mounted, it appeared to float cleanly above the steel panels.
Sanding and Finishing the Mantel
The walnut was sanded smooth and the live edge was carefully cleaned up. Sharp edges were softened slightly, preserving the slab’s natural shape.
Several coats of clear finish were applied to protect the wood and enhance the grain. The contrast between the deep black steel and warm walnut was visually stunning.
Completing the Fireplace
With the steel and walnut in place, Jonny added black and clear fire glass inside the firebox. This small detail helped tie the whole design together.
He also installed the new switch plate and checked that all bolts and clamps were tightened. The finished fireplace was now functional, modern, and the new focal point of the room.
The entire renovation dramatically changed the room’s feel. What was once a flat, outdated wall became a bold architectural feature.
Why This Project Works
This fireplace makeover combines industrial and natural elements without overcomplicating the process. The use of cement board, patina-treated steel, and floating wood elements makes it both durable and modern.
Jonny’s step-by-step approach makes the project feel doable for DIYers with basic tools. His solutions for mounting, finishing, and preserving access all show practical thinking.
Using rare earth magnets for an access panel, hidden fasteners, and modular steel cuts are clever, repeatable ideas. These elevate the look without adding complexity.
A Worthwhile DIY Investment
Large indoor projects like this can be intimidating. But Jonny proves that with the right plan, even a major feature wall can be upgraded at home.
This build didn’t rely on custom parts or expensive materials. Instead, it focused on accessible methods and high-impact finishes.
Whether you’re planning your own fireplace refresh or just gathering ideas, this project offers great lessons in design and execution. From demolition to final polish, it’s a clear example of what good planning and solid craftsmanship can accomplish.
Please support Jonny by checking out his website here: https://www.jonny-builds.com/.