More in Crown Molding

How to Install Easy Crown Molding

TOH technical editor Mark Powers demonstrates how to put up lightweight plaster-covered foam molding

Crown molding makes it to the top of most remodeling lists because it adds charm and value to a home, not because people enjoy spending a Saturday try­ing to get the corners just right. Luckily, there's a simple way to beat miter-saw frustration. Trimroc molding from Canamould Extrusions is a lightweight polystyrene foam coated in hard plaster. It cuts smoothly with a handsaw, and, as This Old House senior technical editor Mark Powers shows here, it goes up in a flash with joint compound. No coping, no tricky angles, and ragged joints disappear with a dab of mud. So in just a weekend, you can upgrade a plain room to an elegant space—and still leave plenty of time for the rest of your list.

Call Canamould Extrusions at 866-874-6762 for stock and custom orders and receive discount shipping to the United States


Steps // How to Install Easy Crown Molding
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Weekend Remodel Day-to-day Timeline

 
Step One // How to Install Easy Crown Molding

Weekend Remodel Day-to-day Timeline

weekend remodel day-to-day timeline
Illustration by Gregory Nemec

Weekend Remodel Day-to-day Timeline

Prep Day: Measure the room, then order the molding at least two weeks in advance.

Saturday: Cut all the pieces, install the molding, clean up joints and gaps with joint compound.

Sunday: Sand, prime, and paint the molding.

 
2 ×

Lay Out and Cut the Molding

 
Step Two // How to Install Easy Crown Molding

Lay Out and Cut the Molding

lay out and cut the molding
Photo by Kolin Smith

If you're working with walls that are out of level and plumb, allow your eye, rather than a level, to guide the position of the molding. For best results, focus on getting the crown to look parallel with any neighboring trim. Install it starting at an inside corner and work toward any outside corners.

Hold a strip of molding in place above a door or window casing. Adjust the molding until it looks even with the casing (ask a helper to stand back and look for you). Draw a pencil line to mark this positioning so that you can install the crown at this alignment.

 
3 ×

Cut an Inside or Outside Corner

 
Step Three // How to Install Easy Crown Molding

Cut an Inside or Outside Corner

miter cut an inside or outside corner
Photo by Kolin Smith

To cut the molding at an angle for an inside or outside corner, place it in a miter box upside down and braced against the bottom and side of the box, as if it were angled against a ceiling and wall. Using a handsaw, cut the molding at a 45-degree angle. On an inside corner, the top part of the molding will be shorter; on an outside corner, the bottom part will be shorter.

 
4 ×

Make a Tight Fit

 
Step Four // How to Install Easy Crown Molding

Make a Tight Fit

shave the back of an angled cut to create room for the two corners to come together
Photo by Kolin Smith

Using a rasp or sanding block, shave the back of the angled cut to create room for the two corners to come together tightly at the face.

TOH Tip: Because straight butt joints are so easy to hide with this molding, you can cut the pieces shorter to make it easier to work.

 
5 ×

Install the Molding

 
Step Five // How to Install Easy Crown Molding

Install the Molding

spread a bead of joint compound the length of the molding
Photo by Kolin Smith

The crown adheres to the wall with joint compound, but using too much will allow it to slide down the wall. As the compound sets, support long runs of molding with 8d nails.

Using a 6-inch putty knife, spread a ½-inch bead of joint compound the length of the molding along the top and bottom edges. Spread mud liberally on each cut end.

 
6 ×

Match the Profiles First

 
Step Six // How to Install Easy Crown Molding

Match the Profiles First

push the two mitered ends together to create the inside corners
Photo by Kolin Smith

Push the two mitered ends together to create the inside corners, making sure their faces align in the corner. Match up the detail of the profile first, then use mud to fill any small gaps between the molding and the ceiling on either side.

 
7 ×

Fit Together an Outside Corner

 
Step Seven // How to Install Easy Crown Molding

Fit Together an Outside Corner

press the mitered ends together until mud squeezes out of the joint
Photo by Kolin Smith

On an outside corner, press the mitered ends together until mud squeezes out of the joint. Backfill gaps using your finger or a putty knife.

 
8 ×

Use Nails to Brace Long Runs

 
Step Eight // How to Install Easy Crown Molding

Use Nails to Brace Long Runs

on long runs, place a nail under the molding every few feet and at joints to hold it in place
Photo by Kolin Smith

Along straight runs, push the straight-cut ends to create a butt joint. On long runs, place an 8d nail under the molding every few feet and at joints to hold it in place. Angle the nails up slightly to hide the holes, and sink them enough to keep them in place.

 
9 ×

Smooth the Joints

 
Step Nine // How to Install Easy Crown Molding

Smooth the Joints

use your finger to smooth out the seams where the molding meets the wall and the ceiling
Photo by Kolin Smith

Cleanup will be easier if you clear away excess joint compound while it's still wet.

Use your finger to smooth out the seams where the molding meets the wall and the ceiling. Use a wet sponge to help wipe away the compound and clean up the face of the molding. Don't remove too much compound—if you do, the seams will "hollow" as it dries.

 
10 ×

Fill to Excess

 
Step Ten // How to Install Easy Crown Molding

Fill to Excess

using a small putty knife, push more compound into and over butt joints
Photo by Kolin Smith

Using a small putty knife, push more compound into and over butt joints. Pull the knife over each detail of the profile, leaving the compound a little proud of the joint. Once dry, the excess can be sanded smooth.

 
11 ×

Prep to Paint

 
Step Eleven // How to Install Easy Crown Molding

Prep to Paint

sand down the excess joint compound once it dries
Photo by Kolin Smith

Joint compound is easy to sand, and once you go over the seams where molding meets molding, the joints will almost disappear.

After the joint compound dries completely, sand down the excess using 150-grit sandpaper.

 
12 ×

Mask and Paint

 
Step Twelve // How to Install Easy Crown Molding

Mask and Paint

prime and paint the molding to match the door and window casings in the room
Photo by Kolin Smith

Mask the walls along the edges of the molding with painter's tape. Using an angled sash brush, prime and paint the molding to match the door and window casings in the room.

 
 
 

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