What gauge is specified for the flush metal base ground for plaster?

What gauge is specified for the flush metal base ground for plaster?

• A. 16
• B. 18
• C. 20
• D. 22

Answer: (B)

The main idea is that the metal edge used as a base for plaster must be stiff enough to stay straight and resist denting during plastering, so the finished surface is true and flat. Eighteen-gauge steel provides that balance: it’s thick enough to remain rigid and resist bending as plaster is applied, yet not so thick or heavy as to be impractical or costly. Thinner gauges (like 20 or 22) can dent or bow from trowel pressure, creating an uneven edge or telegraphing through the plaster. Thicker gauges (like 16) are often more than what’s needed for standard work and add unnecessary weight and expense. So eighteen-gauge is specified for a flush metal base ground for plaster.

The main idea is that the metal edge used as a base for plaster must be stiff enough to stay straight and resist denting during plastering, so the finished surface is true and flat. Eighteen-gauge steel provides that balance: it’s thick enough to remain rigid and resist bending as plaster is applied, yet not so thick or heavy as to be impractical or costly. Thinner gauges (like 20 or 22) can dent or bow from trowel pressure, creating an uneven edge or telegraphing through the plaster. Thicker gauges (like 16) are often more than what’s needed for standard work and add unnecessary weight and expense. So eighteen-gauge is specified for a flush metal base ground for plaster.