Beautiful DIY Pellet Stove Insert Fireplace Mantel

We spent a great deal of time searching online for examples of what we were trying to accomplish. There is a ton of amazing work out there, but not exactly what we were looking for. We also had a lot of contradictory advice from different pellet stove dealers, in that many said they did not make a model to be used in a mantel, but the dealer closest to us was helpful and sold us a model that could be used safely for this application.

There were many things to consider before starting the build. We were also building cabinetry on either side that wrapped around the right side wall. We needed to fully plan this out with the actual dimensions of the mantel we were building. We needed to consult the installation manual for the unit, and double check the clearances needed for the stove and for the hearth size. We confirmed the requirements for the floor materials underneath the unit. We went with cement board and marble 18 x 18 tile, to match the surround tile. The tile we chose wasn't overly cheap, but we needed very little of it so it was worth it in the end.

With all of the above considered we needed to layout and install the hardwood floor ensuring the hearth was correctly placed, as we were building it flush with the hardwood. This was a bit tricky but given this was a new build, it was not bad to fit it all in from the start.
If we were building on top of the floor, it may not be as much of an issue to work out.
We also needed to carefully plan the opening of the fireplace mantel, to be sure we could fit the tile and surround that came with the stove. It was a very close fit so it needed to be accurate.
The depth of the fireplace is also a big thing to consider and plan. We needed to be sure we meet the clearance requirements of the unit to our back wall, and the hearth depth.

The floor was installed, and we started building. There was a ton of advice online, to help out with the general construction. We built the basic frame out of 2 x 4" stock lumber.

The next layer was mdf panels carefully placed such that the mouldings (next layer) would hide all of the seams of the panels. The top was two pieces of mdf thick, because we wanted to have a nice thick reveal. We liked mdf because it was smooth economical and easy to paint.

The edges were capped with solid wood. We used a clear pine. The mouldings were a mix of wood and mdf. The top was planned at a depth and width to accommodate crown moulding. We used the same crown moulding in the room.
I was not overly concerned with using mdf because were painting the entire surround white, but you can do as you like especially if you are looking to stain yours.

When we were building the room we planned out the electrical for the fireplace and tv, that was to sit above. You can see the tv outlet above the mantel.  The stove outlet is located behind the mantel to the far right of the unit. We well exceeded clearance requirements because the mantel was so large. We were able to clip in and hide all of our media wires under the top, in order the thread them over to the cabinets to the left of the mantel.
Our finished mantel measures 4.5' tall and 7' wide (top). The depth of the base is 17.5" and the depth of the top including the top is 21".

We installed a level board to help keep our tile from sliding out of place while the adhesive dried.

You can see the line marking the size of the surround that came with the unit. It needed to inset and snugly fit. We did leave a tiny space to accommodate shrinkage.