Plaster ceiling designs are some of the most beautiful elements of classic Victorian home decor. By utilising a few plastic or metal moulds and some plaster of Paris, you can replicate some of these ceiling designs in your own home. Turn your traditional dining nook into an elegant dining room or your plain foyer into a grand entry hall in just a few simple steps.
Buy the plaster moulds you would like to use. Molds come in many shapes and sizes and they can be found at craft stores or purchased from online retailers. The moulds you select do not even need to be plaster moulds, specifically -- candy moulds also work well.
Create the design you would like to apply to your ceiling by arranging the plaster moulds in different patterns. Be creative with circular medallions, flower shapes and decorative borders. Draw out a sketch of the finished product so you know how many casts you will need of each mould.
Mix your plaster of Paris by following the directions on the packaging. Fill a plastic tub or bucket with water and sprinkle the plaster of Paris over the surface of the water, sifting it through your fingers, until the entire surface is coated. Allow the powder to sit for 2 minutes then stir the mixture from the bottom up with a metal spoon.
Stir the plaster of Paris slowly and evenly until it begins to thicken. Once the plaster reaches the consistency of whole milk it is ready to use.
Coat the inside of your plaster moulds with cooking oil to keep the plaster from sticking. Pour the plaster of Paris into the moulds, filling them all the way to the top.
Set the moulds aside to dry. This could take anywhere from 30 minutes to an hour, depending on the size of the mould. After 30 minutes, gently touch your finger to the plaster. If it feels warm or if your finger leaves an imprint, the plaster has not completely set.
Pop the plaster castings out of the moulds by turning the moulds upside down over your hand and gently press the casting out of the mould from the back and into your open hand. Set the plaster pieces in a warm, sunny area or near a radiator to dry for 24 hours.
Transfer your sketched design to the ceiling in pencil. Use a measuring tape or ruler and mark the exact position for each of the plaster moulds.
Paint your plaster moulds, if desired, with acrylic paint for bold colours or watercolour paint for subtle colouring. Allow the paint to set for several hours until it is dry to the touch. Apply a layer of clear matt acrylic sealer to protect the moulds from moisture. Allow the sealant to dry overnight.
Attach the plaster castings to the ceiling by spreading a 1/4-inch layer of joint compound on the back of each piece with a putty knife. Press the moulds into the ceiling in the desired location and hold each one in place for 30 to 60 seconds. Fill in any gaps around the mould with joint compound to create a cohesive look. Wipe away any excess joint compound with a damp sponge.
Be creative with your ceiling design. Use ornamental borders to line tray ceilings or circular moulds around hanging light fixtures. Use whatever design you want but avoid adding too many plaster moulds or your ceiling may end up looking tacky rather than elegant.
Wear latex or plastic gloves when mixing the plaster of Paris to avoid irritating sensitive skin, and wear a face mask to avoid inhaling the powder.