Repairing plaster details

Re-attaching decorative plaster pieces

Some of the decorative plaster border was loose or missing. We removed the loose pieces, and collected other pieces that had fallen from less conspicuous areas of the ceiling. 

Then we stuck them back up! Basically: 

  1. Put dollops of mud on the back
  2. Press up into the gap
  3. Hold to secure
  4. Touch up the edges with additional mud
  5. Wipe off excess mud


Horse hair plaster

In the later 1800s/early 1900s plaster was made of lime and/or gypsum. Lime plaster was made from four ingredients: lime, aggregate, fiber, and water. The lime came from ground-and-heated limestone or oyster shells; the aggregate from sand; and the fiber from cattle, hog, or horse hair. The fibers hold the plaster together, keeping it from cracking. 

Read more about plaster work and the history of plaster in the National Parks Service Preservation Brief #21.