Paul Ricalde | January 01, 2018


YouTube // Trimwork & Cabinetry

Cutting Crown Molding on the Flat

 

Forget about upside-down and backwards, just lay it on the table and cut it

There is a lot more to cutting and installing crown molding than there is to cutting and installing baseboard or any other molding that sits flat against the wall. Those cuts are two-dimensional.

Because crown molding bridges the ceiling/wall planes, the face of the molding is not in plane with either surface.

And the cuts are even weirder.

 

Two ways to cut crown molding:

One way to cut crown molding it to use the 90 degree intersection of the table and fence on a miter saw to play the part of wall and ceiling. When doing this, the fence plays the part of the wall and the table plays the part of the ceiling.

So the crown molding sits upside down on the saw. The saw blade can be swung 45 degrees, and the blade will slice a perfect compound miter in the crown.

The other way to cut the crown molding it to lay it flat on the table and use the bevel adjustments of the blade to dial in the correct compound miter angles. To cut this way, you need to know the spring angle of the crown molding and the bevel.

 

Critical definitions

spring an·gle | spriNG ˈaNGɡəl (noun)

"The angle between the back of the molding and the wall, when the molding is installed."

—Gary Katz  in Spring Angles and Angle Finders​ 

The main spring angles are 45/45 and 52/38, corresponding with the top and bottom angles on the crown molding, respectively.

To find out what the spring angle is, set the crown molding into the crotch of a framing square and check where the ends align. if both numbers are the same, it is 45/45 crown. If the numbers are different, such as three inches on the wall and two inches on the ceiling, it is  52/38 crown.

 

bev·el |ˈbevəl (noun)

"The angle which one surface of a body makes with another surface when they are not at right angles."

—Dictionary of Architecture and Construction, McGraw Hill

Tilt the blade to cut the bevel.

 

mi·ter |ˈmīdər (noun)

"A joint made between two pieces of wood or other material at an angle of 90 degrees such that the line of junction bisects this angle."

—The New Oxford American Dictionary

Swing the table to cut the miter.

To find the correct bevel and miter angles use a big chart, like the one here, at GaryKatz.com, or use a smaller chart, such as this one, which was laminated for jobsite use by a carpenter named Bruce Abernathy:

Chart of bevel and miter angles for how to cut crown molding flat

 

Some miter saws also have charts built right in to them, such as the chart on this Bosch miter saw showing how to cut crown molding on the flat as well as "upside-down, and backwards":

Crown molding angle chart from Bosch miter saw

 

 

A few tips for cutting:

Make a couple of sample pieces—a pair of inside and a pair of outside corners. Use these samples to check the angles against reality, and to help you visualize the molding in place, when you are standing at the saw trying to remember which way is up.

When cutting from an inside to outside corner, Paul recommends cutting the inside corner first because it is easy to hook the end of the cut with a tape measure to mark the next cut.

When measuring short point to short point, such as for outside to outside corners, you can do one of two things:

  • Burn an inch and subtract from your measurement, which works well for short pieces.
  • Clamp a speed square to the crown molding aligned with the short point and hook the speed square with your tape.

Man with tape measure and speed square describing how to cut crown molding flat

Align the blade with the edge of the line and cut. Do not cut the line, leave it.

Test drive the piece to make sure it fits, with the line left, you should be able to trim it into position if needed.

There is a lot more to hanging crown molding than this short introduction, but we will leave it there for now.

 

—Paul Ricalde is a home improvement contractor and fireman in New Orleans, LA. His YouTube channel is rich with construction/remodeling videos.

 

Chart of bevel and miter angles for how to cut crown molding flat
Crown molding angle chart from Bosch miter saw
Man with tape measure and speed square describing how to cut crown molding flat

Comments

 

 

No, it's not 'up to what you want' on placing 45/45 crown.

THE COVE GOES DOWN!  Always. Period.

It's architecturally incorrect any other way.  Period.

 

All the other info was spot on

 

I realize that the cove or detail should be placed with the cove on the bottom, I try to explain that in this video without insulting anyone and I am not going to be (the person) that tells them the crown is upside down in their home. I personally would never put crown with the cove (detail) on the top, but some 45-45 crown has detail throughout and others have the same detail on the top and bottom (double bead crown). This crown can be place either way. 

Wanna bet the designer/manufacturer has a different opinion?wink

Never encourage bad decisions....

Show me proof, I personally deal with molding suppliers all the time and they are in agreement with me. I think you are reading my video wrong and you are missing the point! That's ok with me, everybody has their own opinion and I respect yours. I stand by mine.

I bet this guy doesn't have too many happy customers with that attitude of "It's the way it was designed by the manufacturer, we can't install it the other way"

Hey Paul, info you got on installing crown on raked walls?

Thank you for the videos and Who Dat!

I have a crown that has a 52 degree spring and the breadth is 7 inches. My 12 inch compound miter saw can't cut it the "easy" way because the breadth is too long. The design has a concave angle to it so I can't cut it flat decorative side up, so my only stable option is to cut it decorative face side DOWN.
PLEASE, HELP ME. I've wasted a good $50 in crown so far trying to find a good angle.

As someone that has installed literally miles of crown molding in many of Florida's finest homes.  From small single stage crown molding  to a six stage framed crown 25 ft in the air that was over 36 inches in height.  I am impressed with your trim skills as well your video.  Had to comment . I understand where the other poster is coming from but in this case disagree with him about that particular profile.  Not that we all have not came across a crown profile that has us scratching our heads but I definitely agree with you that the profile can go either way.   

Kevin Harmon 

Winter Park Trim and Door  http://winterparktrim.com
Orlando Florida

What measurements do I use to get the perfect outcome with the tilt bevel or however you wanna say it tried all day cutting both ends messed up bad need help for tomorrow

I have crown to install outside under a soffit      wall to soffit angle is 70 deg  I would like to cut on the flat. I have altered the angles cuts on each side to match the wall and soffit so both cuts fit against there surfaces flat. Can you help me out thanks 

Great video and tips, just make sure to wear safety goggles when you cut. wink

Cutting crown on the flat is most accurate way to cut crown molding.The crown is flat and tight up against the fence which gives a more accurate cut and you dont waste any material on screw ups from looming at it the wrong way.Too much confision for me.On a fence upside down the crown tends to flex more giving you an inaccurate cut and better hope their isn't a crown in the middle of your crown.You won't be able to push the crown down and out unless it is on a flat table.I can crown a whole house and only move my saw out of position maybe 4 times the whole house.You set up the saw for a 90 degree cut then just flip your material up side down.Once you go flat,You never go back.

only thing i can say is I cope all inside corners wouldnt allow anyone to put crown or base in for me that is using 45 degree cuts on inside corners theres always gapping if not at first for sure later 

 

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