Real wet plaster and lath, 100 years old.

Real wet plaster and lath, 100 years old. #homeinspectortraining https://globalinspectionschool.com/

Wet plaster and lath is a traditional building technique where thin wood strips (lath) are nailed to wall studs, and then multiple coats of wet plaster are applied over them, pushing it through gaps to form "keys" that lock the plaster to the wall, creating a durable, solid interior finish used before drywall became common.
How it works:
Lath: Narrow strips of wood (or sometimes metal) are horizontally nailed to wall studs or ceiling joists, leaving small gaps between them.
Plaster Application: A mixture of plaster (often gypsum, sand, lime, and water) is applied in layers.
Keys: The wet plaster is forced through the lath gaps, hardening on the inside of the wall as "keys," which are crucial for holding the plaster system together.
Layers: Plasterers apply several coats (scratch coat, brown coat, finish coat) until the wall is smooth and hard.
Key characteristics:
Durable & Solid: Creates very strong, fire-resistant, and sound-dampening walls.
Labor-Intensive: Requires skilled labor and significant drying time.
Pre-Drywall: The dominant method for interior walls from the 1700s until the 1940s, largely replaced by faster drywall installation after WWII.
Modern Use: Still used for historic restoration or high-end finishes but rarely for new construction.