Widen the crack so that the new plaster will stick to the old plaster, then spread patching plaster over the area.

Millions of homes have plaster walls, the precursor to drywall. In fact, many modern homes are still constructed with plaster, especially homes built with a retro look. Drywall isn't better, it's just cheaper to install and requires less skill than plaster. If you live in a home with plaster walls, here's how to fix them.

 

How Does It Work?

Plaster is a pasty composition of lime, water, and sand that hardens when it dries. It's used for coating walls, ceilings, and partitions. Plaster is spread over masonry or lath (strips of wood, metal, or gypsum). In older homes, plaster was applied in one to three coats. All-purpose, one-coat plasters are now available to make plastering easier. There are numerous plaster-patch products available to make repair easy, too.

What Can Go Wrong?

Plaster walls and ceilings can develop small to large cracks from drying or ground movement. Furniture, doorknobs, and other objects also can make holes in plaster. If it becomes wet, plaster can bulge or even disintegrate.

Fix-It Tip

Which plaster? You can patch a hole in plaster or drywall with joint compound, spackling compound, or patching plaster. Each has advantages and disadvantages. Joint compound applies smoothly and sands easily, but takes 24 hours to dry and it shrinks. Spackling compound dries quickly and shrinks minimally, but is harder to sand smooth. Patching plaster dries in as little as two hours, doesn't shrink, and is durable, but it is difficult to sand.