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2018 National Home Improvement Estimator, All Rights Reserved Page 227

Chapter 10, Walls and Ceilings

Before about 1950, most homes were built with interior walls and ceilings finished in lath and plaster.
During the 1950s, gypsum wallboard became generally available and most owners and industry
professionals switched over. While plaster and gypsum wallboard are equally durable (when protected
from moisture and impact) and both make attractive wall and ceiling coverings, gypsum wallboard is
preferred because it’s so much less expensive to install. Lath and plaster is very labor-intensive, and
because it requires days or weeks to dry out, it tends to delay construction. Today, it’s unlikely you’ll
be called on to do a lath and plaster job. But you may have to make repairs on one.

Nearly all plaster develops hairline cracks. These cracks and small holes must be patched with
patching plaster or joint compound or spackle before repainting. Plan on covering or replacing the
surface if plaster is uneven, bulging, loose, or there are many large holes. If there are only a few large
holes, you can patch them. If there are more than a few, it’s easier to replace the entire wall. Loose or
bulging plaster is a sign of water damage. When you find damage caused by water, your first step will
be eliminating the source of moisture. Otherwise, the repair will be worthless.

Gypsum wallboard is usually called drywall, though you’ll hear the same material referred to as
wallboard, gypboard, Sheetrock or simply rock. The term drywall is a little misleading. First, drywall isn’t
just for walls. It adapts equally well to installation on ceilings. Second, drywall is dry only by
comparison with plaster, which goes on wet. The cement (sometimes called mud) used to cover drywall
joints is mixed with water and needs at least a few hours to dry completely.

Drywall does have its problems. Unlike plaster walls and ceilings, it can develop nail pops – nail heads
that work loose and rise above the surface. Also, the paper tape used to cover panel joints can
de-laminate and curl if not bedded correctly. Loose tape is a sign of a poor drywall job.

Choices for Renewing Wall and Ceiling Cover
1. Patch and smooth what’s there. This is the least expensive choice. But it’s not practical when walls
or ceilings are seriously damaged.