How to Install Ceiling Moldings


– Step 1: Clean the surface

– Step 2: Prepare the media

– Step 3: Locate the location

– Step 4: Install the moldings

– Step 5: Do the finishing touches

– Step 6: Cut the cornices

– Step 7: Place a rosette


Ceiling moldings are ornaments of various shapes and styles that can highlight the decoration of a room.

Polystyrene moldings are very inexpensive but poorly finished. They are available in plaster and polyurethane, at a higher price, but with a much better finish. They are glued down (the glue to be used is dependent on the material).

Modern, baroque, classical, fixed in cornice or rose window, these decorations are straightforward to install. You will have to respect a few small instructions for the support.

Here is how to install decorative moldings on the ceiling.

Caution: Try to adopt the most comfortable position on your stepladder, never work at arm’s length!


Materials for installing moldings on the ceiling

Alkaline detergent

$3 approx.


$1 approximately


$20 approx.


From $1


Recovery materials

Glues Approximately

$20 per 8 kg

Plugging Coating (tube)

Starting at $3

Seal Gun

Starting at $6

Self Saw

Starting at $3

Mitre Boxes

Starting at $4

1. Clean the surface

The substrate must be free of dust, grease and dry to optimize the adhesion of the moldings.

– Sponge the ceiling with St Marc detergent diluted in water.

– Wait for it to dry completely before starting to install the moldings.

2. Prepare the surface

– If the substrate has some cracks or unevenness, use a filler to fill them.

3. Locate the area

– Position the molding in its final location.

– Draw its support line on the ceiling with a light pencil stroke.

– This is a critical operation; it will allow you not to hesitate when installing the molding. It is even more important when installing a cornice.

4. Install the moldings

– Read the instructions carefully for using the adhesive, especially the setting time.

– Apply the glue:

◦ In blocks, using a spatula if the glue is in a pot.

◦ In strings, if the glue is in cartridge form.

– Also, glue the ceiling surface for polystyrene and plaster moldings.

– Install the molding.

– Press evenly.

– Remove excess glue with a damp cloth.

Caution: Use the correct glue for the molding material; other adhesives may attack incompatible materials.

5. Finish

– Wait for the glue to dry.

– Hide the joints between several elements (if existing).

– Use ready-to-use filler, applied with a spatula or finger.

– After the filler has dried, you can even paint the moldings.

6. Cut out the cornices

– Put the cornice in place.

– Draw the cutting line with a pencil.

– Use a mitre box and its saw to make clean cuts.

– Cut at 45° for corner joints, but also in a straight line.

– Hold the cornice firmly in place inside the box when sawing.

7. Install a rosette

In addition to the aesthetic function, the rosette can also be used to conceal the mounting of a luminaire.

– Before intervening, turn off the electricity at the meter.

– Cut a hole of a few centimetres in the centre of the meter with a cutter to allow the passage of electrical wires.

– Proceed with the installation in the same way as simple molding.

– Take good care of the finish; the rosette will be in full light.

That’s it. You are now done with installing ceiling moldings. Please, remember to share this post and leave your comments in the section below.

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