Types of Plaster Finish in Old Houses

Construction

• Plaster walls are held to structural members with lath, which can be thin, wood strips or galvanized steel mesh. The 1930s saw the introduction of paper-faced rock lath, which is similar to drywall. Plaster is installed over the lath in at least two finishes. Houses built before 1900 used age-old lime plaster, while later houses mostly used newer, gypsum-based plaster still in use today.

Smoothness

• Super-smooth plaster walls are not only beautiful but evidence of excellent craftsmanship. The top coat of plaster was smoothed -- or slaked -- so the plaster hardened to a glassy texture. The raw, gray plaster was often left on ceilings unpainted, while walls were painted or papered according to the fashion of the day.

Coarse

• Some homeowners spend many weeknight and weekend hours stripping wallpaper, only to be disappointed by coarse, sandy plaster that is not suitable for painting. In the building booms of the late 19th century, the smooth plaster skim coat was skipped to cut costs. The sandy finish was perfectly suitable for wallpaper, which was standard fashion for many decades.

Textured Walls

• The revival of romantic housing styles gave rise to interior textured plaster, which was applied with a bumpy texture resembling small valleys and flattened peaks. These walls were popular in Tudor- and Spanish-style architecture. Large swirls and rough rakes of plaster were reminiscent of ancient Italian or Southwest structures. Interior plaster texture often matched stucco plaster on a house's exterior.

Tips

• Unless you are an advanced do-it-yourselfer, leave large plaster jobs to professionals who specialize in using old, traditional techniques. Small repairs, however, can be made using spackling compound and latex caulk. If you're building a new house and would like to achieve a hard, smooth plaster finish economically, a professional can apply a plaster skim coat over sheetrock. If you have sandy, textured walls and don't want wallpaper, apply a wall-canvasing product to prepare them for paint.