lath

Picture an old house before drywall became common. Behind the plaster, there were often thin strips of wood fixed across the wall studs. These strips gave the wet plaster something to push through and hold onto as it dried. That is the main meaning of "lath." Today, people mostly meet the word in "lath and plaster" walls, in repair work on older buildings, or in simple slatted structures such as screens or garden panels. There is also an old, rare meaning referring to a thin rod or switch, but that use is now uncommon.

Lath is a thin, narrow strip of wood or metal used in building. Historically, its main purpose was to form a base for plaster on walls and ceilings. Instead of putting plaster directly onto solid boards, builders fixed narrow strips across the studs or joists, leaving small gaps between them. When wet plaster was pressed on, some of it pushed through the gaps and hardened behind the strips, forming a "key" that helped hold the surface in place. This method produced the strong lath-and-plaster walls found in many older buildings.

The word can refer either to one strip or to the full layer of strips that supports the plaster. You will often see this called "lath and plaster" construction. Although drywall has largely replaced this method in modern building, the term still appears often in restoration work, where older walls and ceilings need to be repaired with traditional materials and methods.

Beyond that main building sense, "lath" can also refer to narrow strips used in open frameworks such as screens, fences, or garden structures. This meaning grows naturally from the same basic idea: long, thin pieces set in rows or crossed patterns.

There are also older, rare meanings. In historical writing, "lath" may refer to a thin switch or rod, and in some older theatrical contexts it could mean a light wooden sword used as a stage prop. These uses are now archaic. For most learners, the important meaning is the building one: a thin strip, usually of wood, especially one used as part of a support for plaster.