With their exquisite patterns and clean colors, plaster cornices have graced people's homes for thousands of years, ever since the ancient Greeks used them to decorate their temples. Nowadays, although not as frequently used as before, plaster cornices can still be found in many buildings all over the world, from aristocratic palaces to modest Victorian houses. Unfortunately, because of their composition, these delicate cornices are prone to deterioration and wear-off that require immediate restoration and regular maintenance.
The present guide will teach you how to repair any broken plaster cornice that you may have in your house.
Step 1 - Make Requisite Preparations
With a wet sponge, clean the damaged area from any dirt and loose plaster particles. Take the scissors and cut the Styrofoam in approximately the same size as the missing cornice part. Make sure the Styrofoam piece is not thicker than the cornice so that it does not stick out.
Step 2 - Repair the Cornice
Using the taping knife, apply some plasterboard adhesive over the cornice gap and then place the cut-out Styrofoam piece upon the adhesive. Spread another coat of the adhesive on top of the Styrofoam and smooth it over with the taping knife. Allow 24 hours for the adhesive to dry.
If there are bits of adhesive that protrude over the plaster cornice, sand them down with fine-grit sandpaper. Then, prepare a mixture of plaster and water by adhering to the manufacturer's instructions. Once the mixture is ready, apply a coat of it over the adhesive, following the curves and shapes of the cornice.
Step 3 - Apply Second Coat of Plaster
Since plaster is a frail material that can easily shrink and crack, it is better to spread another coat of plaster–once the first has dried–in order to strengthen the repair work (for plaster application, it is best to use the taping knife). Be particularly careful when applying the second plaster coat, as it will be the front of the cornice that people will be looking at.
Step 4 - Finishing Touches
If the final result is not satisfactory, you may want to hone the figures on the replacement piece with a fine chisel or sandpaper. After you perform this operation, wipe the cornice with a damp sponge and wait for it to dry.
Step 5 - Apply a Coat of Paint
As a final step to the cornice restoration you may want to consider applying a layer of paint over the repaired area. Currently, there are numerous reasonably priced plaster paints, which you can order online or purchase at your local hardware store. Some paint brands (a notch more expensive than the regular ones) will not only refresh the color of your cornice, but will also protect the cornice against the elements for years to come. It is best to use one of these in compliance with the manufacturer's directions.