How to Care for Plaster in an Old House

Save the plaster! This might have been the rallying cry of Julia Child, were she a preservationist rather than a chef.

“Preserving nice plaster work, if possible, is always worth it,” reBUILD Workshop LLC President Themis Haralabides told Brownstoner. “After all, it is usually one of the reasons people like older houses in the first place.” 

 Plaster walls and decorative details are high-quality, handmade finishes that give an old house character. They should not be replaced with inferior materials without a compelling reason. Plaster is worth preserving and, fortunately, easy to maintain — all you need is a little knowledge.

What is plaster
Plaster is an ancient material that goes back at least to the Egyptians. Its exact composition has varied considerably through the ages, but in modern times it typically consists largely of plaster of Paris, otherwise known as gypsum.

It is applied by hand and dries to a very hard finish that can last pretty much forever — as long as it isn’t damaged by water or cracked or separated from its underlying material by movement.

Decorative, ornamental, and architectural plasterwork goes on top of flat plaster walls and ceilings. Examples include wall moldings, crown moldings, moldings on the ceiling, plaster medallions, and fanciful floral decorations or scrollwork just below crown moldings or on vestibule walls. The most elaborate plasterwork is usually found in the parlor.

“In 19th century and early 20th century houses plaster work was a means to express social status,” said Haralabides. “The more ornate the plaster work, the wealthier the owner.”

Advantages of plaster
Plaster has many advantages over modern drywall. It provides better insulation, fireproofing and soundproofing than drywall. Also, unlike drywall, it will not harbor mold because mold cannot grow in it.

Because it is hand applied by skilled artisans, it is a higher quality, more expensive material. When building a new house, real plaster walls are more expensive than drywall. But in an old home that already contains plaster, it is almost always more cost effective — and more attractive — for the homeowner to keep the plaster than replace it.

“Plasterwork appeals to people who care about the long term quality of their interior,” plaster expert Jason K. of Urban Plaster Restoration told Brownstoner. “The material, as is the case with many other high-quality materials, has properties that can enhance an interior space in an aesthetic and physical manner. People feel better in a space in which quality plasterwork has been done. Additionally, quality plasterwork can be a boon to resale value, especially in a market where people prize preserved, pre-war detail,” he added.

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