How to cut crown molding with a miter box


Crown

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And we’re back for another post on my still-almost-totally-completed office!

Today I’m going to talk about how I cut and installed crown molding using only a miter box. I watched a lot of YouTube videos and read a lot of articles on installing crown. What I took away from it is that crown molding is confusing and you have to watch what you’re doing. There was a lot of “remember, you cut crown while it’s upside down” and “remember, an outside corner means that the long part is on the top”. Huh. I see.

I’m wholeheartedly unashamed to admit that a lot of things I do around my house I’m doing for the first time. I’m not an expert and I will never claim to be.  The things I share on this blog are meant to instill confidence that the unknown can be tackled if you’re up to the challenge. Hey, if I can figure it out, I’m pretty sure anyone can.

At some point, I probably will invest in a fancy miter saw. It seems like one of those “must-have” tools and all the hardcore DIY folks have them. For this project though, I liked the idea of something simpler since the crown itself was one of the more challenging materials to work with. The price tag wasn’t too bad either. I bought a simple miter box for around $15.00. In fact, it was this one.

I just bought the basic primed crown that runs about $10 for an 8-foot piece. It’s really similar to this.  All in, this piece of the project cost around $100, maybe a little more. Once I had all the materials and had measured about 18 times it was time to start cutting.

Crown is cut while it’s upside down.

But here’s something interesting I discovered during my research – which side of the crown molding is considered the top is actually subjective. The generally accepted method is the side with the decorative details is the “wall side” or the side that’s on the bottom as you look at it. The other option is to put the decorative side against the ceiling. I chose the traditional option because I liked the way it looked.

When measuring for crown, it’s important to measure at the top of the wall where the molding is actually going to sit.

Not all rooms are built at perfect 90-degree angles so the measurement you get in the middle of the wall might not be the same at the top near the ceiling.

The other thing to keep in mind is what type of angle you’re going to be using. For an internal corner, the wall edge is going to be the longer side. For an external corner, the ceiling edge will be longer. So when you measure, especially if you’re transitioning from an internal corner on one side to an external on the other, make sure you account for the long edges.

Figuring out which way to cut depending on the corner is probably the most confusing part of this whole process. I Googled and watched a lot of videos. It seems like there are a massive amount of different tips and tricks people use to get this right. Below I’m going to show the method I ended up using based on everything I researched.

First off, get to know your miter box because this is key to getting the cuts right. The box has slots on the sides for 90, 45 and 22.5-degree cuts. We’re all about the 45 for this. Which side and which direction you’re cutting determine the corner you’re cutting for. I’m going to lay that out below.

miter box for crown moulding

For an internal corner that’s on the left side (as you look at the wall), you’re going to place your crown molding upside down on the left side of the box. Again, upside down depends on which side you chose as the top. I chose to put the decorative end at the bottom so I placed the crown in the box with the decorative side at the top. Clear as mud? Placed it in the box the same way it’s going to sit on the wall. It should be angled and not flat against the side. You can secure it in the box while you’re cutting by using the pins provided with your miter box. Then cut from the bottom right to the top left using the 45-degree angle slot. 

Crown Molding, Internal corner, left-hand side

miter box for crown moulding left corner

For an internal corner that’s on the right side, you’re going to place your crown molding upside down on the right side of the box. Then cut from the bottom left to the top right using the 45-degree angle slot. 

Crown Molding, Internal corner, right-hand side

miter box for crown moulding right corner

For an external corner that’s on the left side, you’re going to place your crown molding upside down on the left side of the box. Then cut from the bottom left to the top right using the 45-degree angle slot. 

Crown Molding, External corner, left-hand side

miter box for crown moulding left corner

Finally, for an external corner that’s on the right side, you’re going to place your crown molding upside down on the right side of the box. Then cut from the bottom right to the top left using the 45-degree angle slot. 

External corner, left-hand side

miter box for crown moulding right corner

Hopefully, that helps demystify the art of installing crown molding a little. Luckily, the method above helped simplify it for me and I’m happy to report I made zero wrong cuts.

The installing part was a breeze after the stress of cutting. To finish it up, I just needed a little paintable silicone caulk and some touch-up paint. The room looks so much more finished and polished now. The white trim in here really sets off the calming colors of the walls and ceiling and I couldn’t be happier with how it turned out.

Crown moulding complete

Next up, I’ll be sharing with you a pleasant little surprise I encountered. The pic above gives a hint but let me say, a happy dance ensued after I found it. No pics of said happy dance will be provided or else you might think I was having a seizure.

One of the most confusing DIY jobs in the world is cutting and installing crown molding. Check out my tips for cutting crown molding correctly every time using nothing more than a simple miter box available from any hardware store.Cutting crown molding is HARD for beginners. And even for more experienced DIY'ers too! If you don't have a miter saw, check out how you can cut crown molding correctly the first time using a cheap miter box.

Sharon

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