Lath and plaster refer to an interior wall construction technique that usually predates the 1940s. Four-foot strips of wood, usually 1 inch wide, are nailed directly to the open studs. The slats are then embedded in three layers of wet plaster. The plaster dries to form a hard, smooth surface suitable for finishing, with primer followed by interior paint or wallpaper. Plaster and lath wall systems are rarely used today, except to restore existing walls or renovate historic buildings.
One of the oldest and most durable cladding systems is plaster metal lath and Portland cement plaster, and despite the obsolescence of this system, it continues to grow in popularity. When considering slats and stucco slats, think expanded metal slats or woven wire slats, depending on what part of the country one lives in, and Portland cement plaster.
Plaster Metal Lath
We supply sheet metal lath in two types: diamond metal lath and rib metal lath. Flat diamond metal lath is not used over solid surfaces like gypsum, concrete, and wood sheathing. Because a flat sheet will only cause the stucco to bond only to the sheathing and not complete the embedding process.
Therefore expanded metal mesh is usually self-furred: dimpled and V-grooved. Diamond metal lath, for its unravel feature, is especially suitable for high-strength needed architectures. Rib metal lath is expanded metal made sheet with ribs to increase the strength of its overall structure. Strip lath and corner lath are also available for installation convenience.
Lath and plaster walls are typically thicker than most drywall panels. Fireproof or X-shaped drywall is 5/8" thick. Gypsum is usually thicker than this. Lath and plaster walls are considered thicker than gypsum board when the lath is factored into the thickness. More importantly, drywall has a consistent thickness, while lath and plaster systems may have inconsistent thicknesses, resulting in gentle ridges and slopes.
Lath and plaster walls can provide better sound insulation in a room than regular thickness (1/2") gypsum board walls. However, an acoustical gypsum board is comparable to lath and plaster walls in terms of sound insulation. Lath and plaster walls have slightly better insulation R-values than drywall systems.
While lath and gypsum walls are inexpensive materials, they are much more expensive to build because they require skilled labor. Drywall is inexpensive to hang and finish.
Homeowners can repair lath and plaster walls themselves using drywall materials and tools. Some companies that specialize in drywall finishes may also be able to repair plaster walls. Metropolitan areas with large numbers of older homes often have tradesmen who specialize in plaster application and repair. Drywall is easy to repair. A damaged gypsum board can be split out and replaced with a new gypsum board.