Plaster Cornice Installation

A cornice can provide an ornamental feature on wall and ceiling boundaries.

Cornices can give any room a classy finish by creating an ornate and attractive boundary between the ceiling and the wall. A cornice consists of a length of plaster molded into a concave shape containing a pattern. Cornices help to soften the join between ceilings and walls with a rounded effect. Buy ready-made strips of plaster cornice from DIY stores and cut them to the right size before installing them in your room.

Things You'll Need

• Tape measure
• Metal rule
• Pencil
• Utility knife
• Miter block
• Plaster adhesive
• Paintbrush
• Cloth

Instructions

1. Measure around the top of each wall in the room with a tape measure. This will allow you to calculate how much cornice you will need to line the ceiling/wall edge perimeter of the room.

2. Cut off a small 2- to 3-inch section from one length of plaster cornice with a utility knife. Push this section up against the wall and ceiling boundary to indicate where the cornice edges will sit. Mark this position on the wall and ceiling with a pencil and then extend this pencil line around each wall and the ceiling by using a wooden or metal rule.

3. Cut the length of cornice to size with a sharp utility knife. Use a wooden or metal rule to ensure that you cut a straight edge. For corner joins where two lengths of cornice meet, use a miter block to cut the cornice at the correct angle for an accurate join.

4. Score the ceiling and wall surface between the pencil-drawn guidelines to help the cornice adhesive grip the surface. Scratch in a criss-cross pattern with a utility knife.

5. Smear the lower and upper edge of the cornice strip with a plaster adhesive or a gypsum-based adhesive. Apply the adhesive with a regular paintbrush or the supplied dispenser. The adhesive will hold the cornice firmly in place against the wall and ceiling.

6. Push the plaster cornice into place. Ensure that the lower and upper edges of the cornice remain flush with the pencil guidelines you drew earlier. Hold for 1 to 2 minutes to give the adhesive a chance to secure the cornice in place. Wipe off any excess adhesive with a water-dampened cloth. Wait for the adhesive to dry for at least 24 hours before painting the cornice.

Tips & Warnings

• Buy an additional length of cornice to allow for any wastage during installation.

• Wear protective gloves while using adhesives and utility knives.

References

• Let's Do DIY: Fitting Coving and Cornices
• DIY Doctor: Coving, Transform Your Ceiling Project

Resources

• DIY Data: Cornices and Coving