Steps for patching a plaster and lathe ceiling:

  • When originally installed, wood lathe was nailed to the ceiling joists. Plaster mixed with horsehair or goat hair was then forced onto the lathe, forming a key that holds it to the lathe.
  • One option is to cut out the damaged area and install a 3⁄8” thick sheet of blue board and plaster.
  • Cover the work area with drop cloths and work off of a rolling scaffolding platform, which can be rented or purchased.
  • Use a drill/driver to secure a piece of 1x3 strapping to the structure above the ceiling. Repeat this process several times in the area of the cracks.
  • For areas where there is no structure above, attach a piece of strapping perpendicular to the others and insert filler pieces of strapping in the gaps between the strapping. Slowly tighten the perpendicular piece.
  • Use a drywall screw with a plaster washer to re-secure the damaged sections of plaster to the lathe.
  • Remove the strapping.
  • For areas where the washers don’t hold or the plaster is very damaged, cut out the plaster and create a patch using drywall. Secure the patch with 1 5⁄8” drywall screws.
  • Scrape away any loose veneer.
  • Mix a batch of plaster and joint compound to ensure good adhesion.
  • Place the plaster mix on a hawk and trowel it over the damaged areas.
  • To keep the plaster from cracking and to hide the screws, set a fiberglass screen into the first coat of plaster.
  • After the first coat sets, apply a second coat, filling any voids.
  • Use a felt pad to finish the job and smooth out the ceiling.

Resources:

The ceiling washers, drywall board, plaster, joint compound, fiberglass window screen, trowel, 13x13-inch magnesium hawk, and felt pad brush can be found at home centers and hardware stores.

Project details

Skill

Cost

Estimated Time

Tools:

Tools & Materials

  • Drill/driver
  • Putty knife
  • mixing paddle
  • Hawk and Finishing Trowel