How to Repair Holes in a Mortar Ceiling

Lay tarps on the floor to protect the surface from abrasive masonry dust.

Remove loose mortar from the border of the hole using your fingers.

Chip away the mortar surrounding the hole to create straight-edged lines eliminating an irregularly-bordered hole. Use a masonry chisel and a 2 lb. hammer to create a square or rectangle. Only chip away the mortar; do not chip out the lath.

Vacuum the dust from the lath and edges of the hole.

Cut a section of metal mesh with metal shears in the same size and shape of the hole.

Place the metal screen inside the hole and fasten it to the lath with galvanized screws or nails.

Combine dry mortar mix with water in a bucket and blend well to create a mud-like consistency. Equip a power drill with a spinner bit to mix mortar.

Paint the lath, mesh and inside edges of the hole with an epoxy bonding agent made specifically for cement materials.

Pick up mortar on a metal putty knife or trowel and push the mortar through the mesh onto the lath while the epoxy bonding agent is still wet.

Pull a notched trowel or concrete rake through the mortar to make raised lines. Apply another coat of mortar over the first coat. Drag a metal float across the repair to smooth the surface. Tilt the float at a 45-degree angle to pull off excess mortar and make the repair flush with the existing mortar.