Repair a Crack in Plaster

mediumHome Repaircheck locally6 steps

Safety Warnings

Wear protective eyewear and a dust mask when removing loose plaster to avoid inhalation of particles

Trowel — Rectangular flat wooden trowel

Straight-edge — Long straight-edge for floating surface

Coarse Plaster — Check locally(As needed)

Plaster of Paris — Check locally(As needed)

Prepare the area by removing loose or damaged plaster to ensure a clean surface for the repair.

Tip: Ensure the area is stable before applying new material.

Apply a layer of coarse plaster to the crack.

Tip: Use a rectangular flat wooden trowel to transfer and spread the material evenly.

Float the surface by drawing a long straight-edge over the wet plaster.

Tip: This scrapes off inequalities and reduces the area to a plane surface.

Allow the material to dry thoroughly before proceeding to finish coats.

Tip: Avoid trapping moisture which could lead to future issues.

Apply a finishing coat of plaster, such as plaster of Paris, if a smooth surface is required for painting or gilding.

Tip: Plaster of Paris is ideal for central ornaments or cornices.

Rub the surface smooth using a straight-edge or sanding tool until it is flush with the surrounding wall.

Tip: Ensure the repair is perfectly level.

For a regular surface, always use a straight-edge to scrape off excess plaster while wet.