Yes, you can absolutely cut crown molding with a miter saw, and it is the most common and effective way professionals handle these tricky cuts. This guide shows you exactly how to master those challenging miter cuts for crown molding using your saw.
Deciphering Crown Molding Profiles and Angles
Crown molding looks great, but its shape makes cutting confusing. Crown molding is designed to fit snugly in the corner where the wall meets the ceiling. This angle is not a simple 45 degrees like baseboard cuts.
The Two Main Ways to Cut Crown Molding
There are two primary methods for cutting crown molding on a miter saw:
- Flat on the Miter Saw Table: This method treats the molding like a long piece of wood cut at an angle. It requires precise crown molding angles settings.
- Coping (or Against the Fence): This involves placing the molding vertically against the saw’s fence, mimicking its installed position. This is often simpler for beginners because it uses standard miter and bevel settings.
We will focus heavily on the second method, as it often yields better results when starting out.
Setting Up Your Compound Miter Saw for Success
To make accurate cuts, you need the right equipment setup. A compound miter saw crown molding setup is essential. This means using both the miter angle (the side-to-side swivel) and the bevel angle (the tilt).
Why a Compound Cut?
Crown molding sits at an angle on the wall. If you cut it flat (a simple miter cut), the resulting angle won’t match the 90-degree corner on the wall/ceiling joint. The compound cut accounts for the molding’s resting angle.
Determining the Correct Angles
The standard wall-to-ceiling angle is assumed to be 90 degrees. However, few rooms are perfectly square. The actual required angles change based on the molding’s profile (how steep or shallow it is).
Most common crown molding profiles are designed to work with standard settings. These settings are known as the “spring angle.”
Table 1: Standard Miter Saw Settings for Common Crown Molding Spring Angles
| Spring Angle | Miter Angle Setting | Bevel Angle Setting |
|---|---|---|
| 38 Degrees | 31.6 Degrees | 33.9 Degrees |
| 45 Degrees (Less Common) | 30 Degrees | 30 Degrees |
| 52 Degrees (Very Common) | 33.9 Degrees | 31.6 Degrees |
Note: For the sake of simplicity and wide applicability, most pros use the 52-degree spring angle settings (33.9° Miter, 31.6° Bevel) if the exact spring angle is unknown. Always test your first cut on scrap wood.
Method 1: Cutting Crown Molding Upside Down (The Lay Flat Method)
This method is excellent if your saw doesn’t tilt well or if you prefer to keep the molding stable on the table. Cutting crown molding upside down means resting the top edge against the saw table and the bottom edge against the fence.
Positioning the Molding
- Identify the Surfaces: Notice which edge rests against the wall and which rests against the ceiling.
- Flip It: Place the molding upside down on the saw table. The edge that touches the ceiling should face the blade (usually the wider edge).
- Secure It: Press the narrow edge firmly against the saw fence. This is crucial for stability.
Making an Inside Corner Cut (Crown Molding Inside Corner Cut)
For an inside corner (like the corner of a room), you need two pieces that meet to form a “V” shape.
- First Piece: Set the saw to your determined miter angle (e.g., 33.9 degrees) and your bevel angle (e.g., 31.6 degrees). Orient the molding so the cut slopes away from you (the back cut). Make the cut.
- Second Piece: For the mating piece, you must reverse both the miter and the bevel settings. If the first piece was cut at +33.9°, the second must be cut at -33.9°. Keep the bevel the same direction unless you are coping.
Miter saw settings for crown molding in this method are dependent on keeping the molding perfectly flush against the fence and table throughout the cut.
Making an Outside Corner Cut (Crown Molding Outside Corner Cut)
Outside corners stick out from the wall (like the edge of a fireplace mantel).
- First Piece: For an outside corner, the cut needs to slope toward you (the front cut). Use the opposite angle setting from the inside corner piece. If the inside corner used +33.9°, the outside corner will use -33.9° (with the same bevel).
- Second Piece: This piece uses the opposite angle again, so if the first piece was at -33.9°, the second piece is at +33.9°.
The key to how to miter crown molding corners using this method is keeping track of which side the angle slopes toward (inward or outward) and ensuring the molding stays tight against the fence.
Method 2: Cutting Crown Molding Vertically (The Coping Method)
This is often called the “against the fence” method and is preferred by many carpenters. It mimics how the molding sits on the wall. Compound miter saw crown molding cuts here use the miter angle for the horizontal corner (90°) and the bevel angle for the vertical spring angle.
Positioning the Molding
- Stand It Up: Place the molding vertically on the saw table.
- Secure Against Fence: Press the edge that goes against the wall firmly against the saw fence.
- Secure on Table: Press the bottom edge (the one going against the ceiling) firmly against the saw table.
This setup means the saw blade slices through the molding as if it were already installed on the wall. You are cutting the angle for the corner junction itself.
Making an Inside Corner Cut (Crown Molding Inside Corner Cut)
For a 90-degree inside corner, you need two pieces that meet perfectly.
- First Piece: Set the miter angle to 45 degrees. Set the bevel angle to the spring angle setting (e.g., 31.6 degrees). Make the cut.
- Second Piece: For the mating piece, you only need to reverse the miter angle. Set the miter to -45 degrees, but keep the bevel angle the same (31.6 degrees).
This setup uses standard 45-degree miter cuts for crown molding on the horizontal plane, while the bevel handles the molding’s slope.
Making an Outside Corner Cut (Crown Molding Outside Corner Cut)
Outside corners are generally easier in this vertical orientation.
- First Piece: Set the miter to -45 degrees and the bevel to the spring angle (e.g., 31.6 degrees).
- Second Piece: Set the miter to +45 degrees and keep the bevel the same.
This method simplifies the angle calculation because the miter is always 45 degrees, regardless of the molding’s spring angle, as long as the bevel is set correctly to account for the slope. This is why many find cutting crown molding upside down easier in some ways, but this vertical method often gives cleaner results for outside corners.
Special Cuts: The Crown Molding Return Cut
Sometimes, molding needs to end neatly against a wall or cabinet, rather than continuing into a corner. This is called a return cut. It involves two steps: a miter cut followed immediately by a coping cut (or a second opposing miter cut).
Steps for a Simple Return Cut
This return directs the molding back toward the wall surface.
- The Miter Cut: Cut the end of the molding piece at the required inside corner angle (e.g., 33.9 degrees, using the settings from Method 1). This cut faces into the room space.
- The Return Cut: Now, you need to cut a tiny sliver off the end that will attach flush against the wall. If you used the “lay flat” method (Method 1), this second cut is made by setting the saw to the exact opposite miter angle (e.g., -33.9 degrees) while keeping the bevel angle at zero degrees (a simple bevel cut, not compound). This small cut squares off the piece so it butts perfectly against the flat wall surface.
This precise method ensures there is no visible gap where the molding meets the wall plane.
Fathoming the Bevel Angle for Crown Molding
The bevel angle for crown molding is the most overlooked part of the calculation. It accounts for how much the molding leans away from the wall. If you skip this, your joint will have a gap at the top or the bottom, even if the center looks tight.
If you are cutting a 90-degree corner, the joint must close perfectly along the entire height of the molding. The bevel ensures this closure happens. If you use the wrong bevel angle, you are effectively cutting the molding at the wrong spring angle, leading to gaps.
Tip: If your room is older, the wall/ceiling joint might not be 90 degrees. Measure the actual corner angle first. Then, divide that angle by two to get the miter cuts for crown molding angle (if not using the vertical method). The bevel angle remains based on the molding’s fixed profile.
Analyzing Crown Molding Angles for Non-Standard Corners
What happens if the corner isn’t 90 degrees? You cannot just use 45 degrees anymore. You must calculate the new required miter setting.
If you are using the vertical method (Method 2), the process is simpler:
- Measure the Corner: Use a digital angle finder or a sliding T-bevel to measure the exact angle of the corner (e.g., 85 degrees).
- Calculate the Miter: Divide the measured corner angle by two.
- Example: 85 degrees / 2 = 42.5 degrees.
- Set the Saw: Set your saw’s miter angle to 42.5 degrees. Keep the bevel angle the same as your spring angle setting (e.g., 31.6 degrees).
This adjustment ensures the two pieces meet perfectly at the 85-degree wall angle, even though each piece is cut at 42.5 degrees.
Safety First When Cutting Crown Molding
Working with a spinning blade and oddly shaped material requires strict adherence to safety rules.
- Always wear safety glasses.
- Keep your hands clear of the blade path.
- When cutting crown molding upside down or vertically, the material can shift unexpectedly. Use firm, steady pressure.
- Never force the cut if the wood binds. Back the blade out slowly and check your setup.
- Ensure the saw is unplugged when making adjustments to the fence or table.
Troubleshooting Common Miter Saw Crown Molding Issues
Gaps in crown molding are common, even for experienced installers. Here are ways to fix typical problems.
Issue 1: Gaps on Both Top and Bottom of the Joint
This means your overall miter angle is wrong. The two pieces are meeting too sharply or too widely at the corner.
- Fix: Check your saw calibration. If you are using the vertical method, try adjusting the miter angle in small increments (e.g., half a degree) until the gap disappears.
Issue 2: Gap Only on the Top Edge
This usually indicates that the bevel angle is slightly off, or the molding is not sitting tight against the fence. The top of the molding is opening up.
- Fix: If using the lay-flat method, check that the narrow edge is firmly pressed against the fence. If using the vertical method, increase the bevel angle slightly (tilt the blade further away from the wall).
Issue 3: Gap Only on the Bottom Edge
This is the opposite scenario; the bottom of the molding is opening up.
- Fix: If using the lay-flat method, ensure the wide edge is flush on the table. If using the vertical method, decrease the bevel angle slightly (tilt the blade closer to the wall).
When in doubt, always cut your first corner on scrap wood and dry-fit it before cutting your final piece. This confirms your miter saw settings for crown molding are correct for your specific saw and molding profile.
Reviewing the Vertical Setup (Compound Miter Saw Crown Molding)
The vertical method is popular because it separates the two angles logically.
- Miter Angle: Controls the horizontal closure (how the corner fits in the room—45° for 90° rooms).
- Bevel Angle: Controls the vertical fit (the spring angle of the molding profile).
When installing an crown molding inside corner cut, you are essentially cutting two small pieces of the corner joint shape and setting them together. The bevel angle determines the shape of the point, and the miter angle determines how tightly those two shapes meet.
Practical Application: The Outside Corner Cut
Let’s detail the outside corner using the preferred vertical method, as this is where many beginners struggle with positioning.
If you have a 90-degree outside corner, you need two pieces that meet at 45 degrees on the horizontal plane, with the bevel set to the spring angle (say, 31.6°).
- Piece A (The Left Side): Set the saw to 45° Miter (Negative) and 31.6° Bevel. Make the cut. This cut slopes away from the saw fence, creating the outside point.
- Piece B (The Right Side): Set the saw to 45° Miter (Positive) and 31.6° Bevel. Make the cut. This cut slopes away from the saw fence on the opposite direction.
When you hold these two pieces together, the angled slope of the bevels ensures they form a neat, sharp point, and the 45-degree miter ensures they meet at the 90-degree outside corner of the room. Mastering this crown molding outside corner cut is a major milestone.
Frequently Asked Questions (FAQ)
Q: Can I use a standard miter saw without a bevel function?
A: It is very difficult. A standard miter saw only pivots side-to-side (miter). It cannot adjust for the molding’s spring angle (the bevel). If you try, you will have large gaps in the joint. You need a compound miter saw or a specialized coping saw setup.
Q: What is the best angle for crown molding corners if I don’t know the spring angle?
A: If you cannot determine the spring angle (often found in the molding manufacturer’s specifications), the closest safe default settings for a 90-degree corner when cutting vertically are 45° Miter and 33.9° Bevel. This corresponds to a 52-degree spring angle, which is common for many modern profiles. Always test on scrap first.
Q: Do I need to use the bevel angle for a crown molding return cut?
A: For the final cut that meets the flat wall (the “return”), you typically set the bevel angle to 0 degrees. You are only using the miter adjustment to turn the piece back toward the wall surface.
Q: Why is my joint tight in the middle but gapped at the top and bottom?
A: This confirms that your miter angle is correct, but your bevel angle is incorrect. The angle of the cut isn’t matching the angle the molding sits at on the wall. Re-check your bevel angle for crown molding based on the specific spring angle of your molding profile.
Q: What is coping versus cutting crown molding?
A: Cutting involves using the miter saw to make a precise, angled cut (miter or compound miter) where two pieces meet at a corner. Coping involves cutting the profile shape of one piece (usually the inside corner piece) so that it perfectly accepts the profile of the adjoining piece, allowing it to fit flush against the flat wall surface without needing a compound cut on the second piece. Many prefer coping for inside corners because it handles slight wall inaccuracies better than a precise miter cut.