How to Cut Crown Molding Inside Corners

Cutting Inside Molding Angles

The best way to cut either kind of corner angle in base molding pieces is by using a miter saw. It will make smooth cuts and be the easiest tool to use. For example, if you are cutting a piece of molding for the left-hand side of the corner, and the right-hand side piece will fit into it, then turn the miter saw left and place it at a 45-degree angle. Then, you just place the piece of molding on the left, right side up, along the top of the saw. Then, cut it on the right side of the base.

When you cut the piece for the right side, you just have to do it in reverse. So, you would put the piece for the right side on the right side of the saw, then turn the saw towards the right at a 45-degree angle and cut the piece of molding. The pieces should match up perfectly.

Video

Step 1: OPTIONAL: Prep Work

I added crown molding to the tops of my “built-in” bookcases (they’re a work in progress). So to start the process (and give the molding something to nail into), I added 1×2 pieces of scrap wood to the corners, middle, and ends of all the places the crown molding would nail into. It’s important to make these sit perfectly flush with the edge of the bookshelf edges.

Setting up your miter saw to cut templates for 38• spring angles

This method of cutting crown molding can be done with any miter saw. 

*These two things are constant:

  1. Set your miter saw to bevel (tilt) left at 33.9 degrees.  (Your saw might say 33.8 — the .1 degree is not enough of a difference to matter.)
  2. Your crown molding always lays flat on the saw.

*These two things will change depending on the cut you are making.

  1. Miter will change between right and left (but at the same setting of 31.6 degrees).
  2. Sometimes the bottom of the molding will rest against the fence.  Sometimes it will be the top.  (The bottom of the molding has the decorative profile.)

Tight miters on recessed jambs

Photo 1: Cut a shim to size

Photo 1: Cut a shim to size

Cut a shim just thick enough to slip under a straightedge spanning the drywall corner. Use this shim to elevate the outside edge of your trim molding (Photo 3) before cutting it.

Photo 2: Cut back the drywall

Photo 2: Cut back the drywall

Trim back the drywall with a sharp utility knife until the trim molding no longer rocks when it’s set in place against the jamb and drywall. Use a hammer to mash and flatten the drywall if necessary.

Detail of shim under the molding

Detail of shim under the molding

Lift the outside edge of the molding up with the shim.

Photo 3: Cut the miter Cut the 45-degree miter on the molding. Repeat the shimming and cutting process for the opposite miter.

Occasionally you’ll run into a door or window frame that for whatever reason isn’t quite flush with the wall. The best solution is to fix the jamb by planing it off if it protrudes or, if it’s recessed, adding thin strips, called jamb extensions. But this isn’t always possible.

If the jamb is only slightly recessed and adding jamb extensions would be unsightly, there’s another solution. First remove enough drywall so the trim can span the jamb and wall without rocking (Photo 2). This solves half the problem. But even now a regular 45-degree miter won’t fit because the molding has to tilt down to meet the jamb. Correct this problem by tilting the trim on the bed of the miter box to match the angle at which it rests against the wall.

Then make standard 45-degree miter cuts. Photo 1 shows how to determine the correct thickness for the shim used in Photo 3 to tilt the trim molding.

Step 3: Measure

Measure your first side that needs to be covered in crown molding.

This measurement will be the length of the BOTTOM of the molding when it’s applied to the item or wall that you’re doing. I say that because on outer corners the top of the molding will be longer than the bottom of the molding and therefore this measurement won’t apply to the top but only to the bottom.

Don’t forget to DOUBLE CHECK your marked line on the molding BEFORE cutting it. Always measure twice, cut once!

Overcut outside corners

Photo 1: Use a knife to mark outside corners

Photo 1: Use a knife to mark outside corners

Mark outside corners with a sharp utility knife. Repeat the marking process on the opposite baseboard. Cut 45-1/2 degree angles on both boards, leaving each an extra 1/8 in. long.

Photo 2: Test fit the corner trim pieces Hold the boards in place to check the fit. If the miter is open on the front, increase the cutting angle to about 46 degrees and recut both sides. Be careful to remove only a hair’s width from each board. Reduce the angle if the cut is open at the back. When the angle is correct, recut each board just to the outside of the marks before nailing them into place.

Getting outside corners to fit tight is trickier than it looks. The key is to make accurate marks with the baseboard in place rather than relying on measurements. And then cut the piece a little long so you still have the option to shave a little from the angle if it doesn’t fit. Since gaps on the back side of the corner are barely noticeable, while gaps on the front are glaring, it’s a good idea to start by cutting slightly steeper 45-1/2 degree angles first. Then if there’s still a gap in the front, cut a slightly steeper angle on both pieces.

You’ll need a compound miter saw or sliding compound miter saw to easily cut tight-fitting miters on a wide baseboard.

Do You Cut Crown Molding Like Baseboard?

Baseboard trim and window and door case moldings are flat pieces of wood stock with a profiled face. Crown molding looks nearly identical. But look a little closer.

Crown molding has small angled faces as well as a large flat spot on the back of the profiled face. This is done by design.

I happen to call these small flat areas the foot and shoulder. Other carpenters may have a different name.

What is the Foot and Shoulder of Crown?

The angled cuts on the back of the trim are actually oriented at 90 degrees to one another. The foot is supposed to rest on the wall and the shoulder contacts the ceiling.

CLICK HERE to get FREE & FAST BIDS from local carpenters who specialize in crown molding.

What's the Best Way to Practice Cutting Crown Molding?

The best way to practice is to cut a few scrap pieces of crown molding. Do this until you get the hang of it.

Take one of your ruined pieces of molding and cut a one-foot-long piece. Get on a step ladder and hold the piece of scrap up to the ceiling and look down the back of the small scrap.

Adjust t so the foot and shoulder touch the surfaces with no gap at all. 

Note how the back of the crown molding does not touch the wall surface. Once you understand this relationship, the rest of the job is easy.

Does the Miter Box Resemble My Ceiling and Wall?

Your miter box has a flat machined table area and a vertical fence that you use as a guide. The vertical fence happens to be oriented at 90 degrees to the flat table surface.

In other words, your saw mimics your wall/ceiling relationship.  The issue is, the saw is upside down as the table of the saw represents your ceiling.

Tips

  • To get the appropriate and correct baseboard corner, be keen while taking measurements and marking. Make sure all corners are at the required angle.
  • There is a high probability that during the first process of cutting, the cuts created by the use of the best portable miter saw may differ. Shape and trim accordingly with accurate measures till the baseboard piece fits.
  • Most of the cut corners hardly get perfect. All you need is to cover the gaps with caulk and other equivalent means.
  • Be keen and take time during the working period to minimize the number of mistakes. You are allowed to reduce the trim to the required length.

HOW TO CUT CROWN MOLDING: COMPOUND METHOD (FLAT)

  • Molding laying with broad back surface down flat on saw table.
  • You must flip the material around to cut both ends of the inside and outside corners.

 

 

INSIDE CORNER OUTSIDE CORNER

Left Side:

  1. Top of Molding Against Fence
  2. Bevel Set at 33.85º
  3. Miter Right at 31.62º
  4. Save Left End of Cut

Right Side:

  1. Bottom of Molding Against Fence
  2. Bevel Set at 33.85º
  3. Miter Left at 31.62º
  4. Save Left End of Cut

Left Side:

  1. Bottom of Molding Against Fence
  2. Bevel Set at 33.85º
  3. Miter Left at 31.62º
  4. Save Right End of Cut

Right Side:

  1. Top of Molding Against Fence
  2. Bevel Set at 33.85º
  3. Miter Right at 31.62º
  4. Save Right End of Cut

* Top of molding doesn’t have decorative edge * Bottom of molding has decorative edge

How do you measure and cut corners on crown molding?

If you discover that your corners aren’t exactly 90 degrees apart, then you need to use an angle finding tool to bisect the angle and get the exact measurement.

Once you have the measurement, take your angle finding tool and line it up on your miter saw with the laser light to create a center line.

HOW TO CUT CROWN MOLDING: NON-COMPOUND METHOD (VERTICALLY NESTED)

Bottom of the crown molding – rest against fenceTop of the crown molding – rest against tableAngled “flats” on back of molding must rest squarely on the fence and base of the sawCrown Molding Vertically Nested Against Fence – Decorative Edge is Always Against the Fence

INSIDE CORNEROUTSIDE CORNERLeft Side:Miter Right a

INSIDE CORNEROUTSIDE CORNER

Left Side:

  1. Miter Right at 45º
  2. Save Right End of Cut

Right Side:

  1. Miter Left at 45º
  2. Save Left End of Cut

Left Side:

  1. Miter Left at 45º
  2. Save Right End of Cut 

Right Side:

  1. Miter Right at 45º
  2. Save Left End of Cut

How To Cut Crown Molding Inside Corner

You cut a crown molding inside corner the exact way you see me do it in this video. Watch it:

To create perfect crown molding cuts, you just hold the crown upside down in the saw as if the saw fence/table represents the ceiling/wall intersection. WATCH THE ABOVE VIDEOS to see how this is done.

Do You Need a Nailing Strip?

It's a good idea to install a triangular nailing strip in the corner behind the crown molding. It should be secured to the ceiling joists, not the top wall plate.

I always install an angled filler strip along the entire length of each wall that fills up the hollow spot created by the angled crown molding. 

You can almost always make a perfect strip cutting a 2×2 piece of lumber at a 45-degree angle with a table saw.

Drive a test nail about one-half inch below the ceiling at random locations to see if you can find this top plate. With this strip in place, you can easily and quickly nail the crown molding in place without using a divining rod or mystic powers to locate wall studs or ceiling joists.

CLICK HERE to get FREE & FAST BIDS from local carpenters who specialize in crown molding.

Remember, my Crown Molding eBook has complete step-by-step instructions with tons of color photographs that show you exactly how to cut crown molding. 100% Satisfaction Guarantee!

Column 234

Summary

Article NameHow to Cut Crown Molding DescriptionDiscover how to cut crown molding. Cutting crown molding is easy if you hold the trim in the saw the right way. Author Tim Carter Publisher Name AsktheBuilder.com Publisher Logo

Cutting Outside Corners for Crown Molding

For left side:

  • Position the molding upside down firmly against the fence stops.
  • Set the miter for a 45° left-hand cut.
  • The piece you will use will be on the right side after the cut is made.

For right side:

  • Position the molding upside down firmly against the fence stops.
  • Set the miter for a 45° right-hand cut.
  • The piece you will use will be on the left side after the cut is made.

Now, see it done in this video:

 

How Is A Miter Saw Used?

Safety

Before you commence performing your woodwork tasks, ensure you are working in a clear, clean, and safe working area. Wear protective clothing including goggles for eye protection.

Operation

Most of the best miter saws are powered by the handles. The blades begin rotating when the handle engages are compressed. Ensure your baseboard pieces are safe and well supported by the best portable miter saw stand or table where necessary.

Baseboard cuts

Baseboard cuts

All marked and well-measured baseboards are supposed to be aligned accordingly. Hold the handles down to engage the blade at all means. With the baseboard piece still in position, lower the blade accurately in a chopping manner. Allow the blade to run through the board. To stop the blade, disconnect the handle. Remove your cuts and raise the blade when done rotating.

You can cut baseboard pieces at an angle by shaping or sliding the saw heads. Miter saws are different, but for shaping both inside and outside corners, it’s advisable to review the manufacturer’s instructions for your model.

How Much Crown Molding To Buy

First, measure the dimensions of the room in order to calculate the lineal feet of crown molding you will need to purchase.

Add at least 10% for waste and practice cuts.

Be sure and measure up where the crown molding will be installed — so that you don’t get caught up in any trim work installed along the lower portion of your walls.

 

How to Cut Baseboard with a Coping Saw

If you plan on cope cutting your molding, you’ll need to grab a few extra items including a coping saw, sand paper and/or wood file. As one reader points out, a jig saw can be used in lieu of the coping saw when you have the right attachment.

The directions are pretty straightforward but this technique takes a little skill. Practice a few corners before you begin your project, and I’d suggest keeping a test piece nearby.

Step 4: Sand for a Tight Fit

Sand the edge and try out the piece. Note any places that need to be sanded or filed down further.

Cut Crown Molding Templates

I’ve included a close up of each crown molding template.  Use the crown molding you plan on installing in your home to create your templates because they not only make determining your cuts easier, they also come in handy when you are installing your crown.

Remember that your saw is set to bevel left at 33.9 degrees and the molding lays flat — for all these cuts.

*The “bevel” is the vertical tilt.

Cut each template about 12″ long according to the instructions below each picture and then write the instructions directly onto each template.  In SHARPIE!  

Project details

Skill

3 out of 5 Moderate Requires basic carpentry skills and experience using a power miter saw

Cost

$200-$600 for an average-size room, depends on size and style of crown molding

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