How to Repair the Plaster Ceiling in an Old House

Cracks

• 1

  Remove loose bits of plaster from the crack by hand. Brush away dust with a hand-held broom.

• 2

  Mix patching plaster with water in a bucket to create a toothpaste-like consistency.

• 3

  Brush on a thin coat of an epoxy-based bonding agent to the edges of the crack.

• 4

  Dip a flexible plastic putty knife into the patching plaster. Press the plaster deep into the crack. Gradually thicken the layers of plaster so they rest a little higher than the ceiling surface. Feather the patching plaster out 1 to 2 inches past the edges of the crack.

• 5

  Allow the plaster to dry completely, usually one to two hours. Sand the plaster surface flush with the existing ceiling surface using 240-grit sandpaper.

Holes

• 6

  Create a square or rectangle around the hole. Place a chisel at a 45-degree angle 1 to 2 inches from the edge of the hole. Face the chisel toward the hole. Lightly tap with a hammer to begin removing plaster. Continue to cut away plaster until you form straight lines and open the hole to a squared figure.

• 7

  Brush away excess dust and pieces of plaster from the lath, which are thin slats of wood under the plaster.

• 8

  Cut a piece of metal screening to fit the hole exactly. Staple the screening to the lath with a heavy-duty stapler. Mix patching plaster with water in a bucket until it is a thick paste.

• 9

  Apply an epoxy-based bonding agent to the rim of the hole.

• 10

  Pick up the patching plaster with a trowel and push the plaster into the small recesses of the screen back to the lath. Layer and smooth patching plaster into the hole until it sits flush with the existing ceiling. Feather the edges of the plaster past the hole onto the ceiling to allow the old and new plaster to blend.