Fireplace Crown

By Jeff | Feb. 20, 2013

With all the shelves finally installed, it was time add the final touches to our fireplace. That left the front piece to cover up the rest of the brick, the crown molding, and the front trim decorations. For the front piece, we used some more of the MDF and secured it in place with some masonry screws. We glued it together first, which may or may not have been the best idea, but we eventually got it to fit and stay straight and plumb.

The next big thing was the crown molding. We had previously purchased this crown molding from Home Depot and painted it ahead of time. For our design, we decided to have the columns stick out about an inch from the inset piece so the crown would look like the top-view design here (the crown is the light tan color).

Since we built the fireplace up square, we can cut the crown so we get 90 degree corners, but that doesn’t mean we’ll be cutting two 45 degree angles as with anything else. Since crown is installed at an angle, we need to take that into account when cutting.

There are two main methods to cutting crown molding. The first involves buying or building a fence to hold the crown molding upside down and cutting it. The second, involves lying the the crown flat and using this handy guide to set your miter saw in the correct orientation. Note that while this works for most standard crown molding, if you’re using a custom size, then you’ll need to use different numbers.

Miter Saw

The first thing is to set your miter saw bevel to 33.85˚. Most miter saws have a special stop at this point. On ours, there’s a tab that flips out to stop the saw at the correct angle. Next, use the information to orient the crown and saw to get the correct cut. Note that this information is for standard US crown molding. If you’re using a custom molding you’ll need different measurements.

Corner Type Side Against Fence Miter 31.62˚ Save
Inside Left Top Right Left side
Inside Right Bottom Left Left side
Outside Left Bottom Left Right side
Outside Right Top Right Right side

Getting the lengths was a bit trickier, but eventually we got the crown in place with our nail gun. Again, the right side proved more difficult, but at least it’s the least visible side and should be fixable with some caulk. We couldn’t believe how big a difference the crown made.

Outside Corner

If you’re wondering about those ugly brown spots, that’s just some wood filler we used to fill the nail holes that hasn’t been sanded down and painted over yet. We’ll show you some more photos of what it looks like afterwards when it’s all done.

Inside Corner

This piece was kind of a pain to cut. The trick was to cut it perfect the first time. Right, like that ever happened. Actually, a push stick and clamp held it down nicely so I could cut it more on the miter saw, and then a file did the rest of the fine-tuning.

The last part of the fireplace building (really!) was adding some decorative trim to the front columns. I measured the distance from the top of the trim and then cut up the pieces at a 45 degree angle, realized I needed another piece of trim at Home Depot, and then nailed it in place. We’ll paint it white once everything else is ready to be painted.

Mantel Crown Moulding