How to Cut Vaulted Ceiling Crown Molding

Lead Image for How to Cut Vaulted Ceiling Crown Molding
  • 6-10 hours
  • Beginner
  • 300-650
What You'll Need
Compound miter saw
Scientific calculator
2 miter saw stops
Angle finder
Miter saw angle chart
Ceiling crown molding
Scrap pieces of crown molding

Ceiling crown molding adds an elegant look to any room, and many homeowners like to install it throughout several rooms for a look of continuity. Installing this type of molding on a vaulted ceiling requires a few specialized tools as well as tool settings. Correctly installing the crown molding requires some angle calculations in order to determine the correct settings, particularly on a compound miter saw.

This type of power tool is the most commonly recommended for this type of project, and it is helpful to have some prior experience using a miter saw on the basic level. Making the cuts in the molding for a vaulted ceiling requires setting the miter saw to angles other than 45 degrees, and these angles are somewhat different for differently-sized ceilings. Luckily, they can be calculated rather easily with only a few steps.

Find the Initial Angle

Begin at one corner where two sections of the wall and ceiling meet. You can use either a manual or a digital angle finder in order to find exact measurement of this section in degrees. Manual angle finders are similar in function to a protractor, though many digital ones have a higher amount of accuracy.

Calculate Miter Saw Angle

Using the angle you measured, divide this by half. This is the initial angle you will need to enter into your miter saw’s settings. Most degree measurements can easily be divided with a scientific calculator, though it is recommended to double-check your calculations with a miter saw chart if you are starting with an angle measurement that does not divide evenly into whole numbers.

Test Your Miter Saw

It is a good idea to have at least two to four pieces of scrap molding in order to try out your miter saw settings and make any small adjustments needed before using it on the actual crown molding for your ceiling. Each of these scrap pieces should be about 12 to 14 inches long. Note that crown molding is cut with the miter saw upside down, using the saw’s table as a guide to fit the molding to an angle equal to that needed to fit with the ceiling. Make sure your scrap piece fits squarely into the miter saw before cutting; this usually requires an angle setting of either 32 or 45 degrees. Also, make sure your miter saw’s locking mechanism is holding your test piece firmly in place before cutting.

Fit Molding to Ceiling

Once you have cut your test pieces, hold them to the ceiling in the same manner you want them to look after installing. If they are not a completely snug fit, you will need to adjust your miter saw angle a bit more. Do so in small increments on additional test pieces until you have a precisely correct cut. Use this exact setting for cutting your real crown molding.