Flush metal base acting as a ground for plaster must be formed of at least No. 18 gauge steel galvanized or coated with rust-inhibiting material. Which gauge is required?

Flush metal base acting as a ground for plaster must be formed of at least No. 18 gauge steel galvanized or coated with rust-inhibiting material. Which gauge is required?

• A. 14
• B. 16
• C. 18
• D. 20

Answer: (C)

The main idea is that the plaster ground base must have a minimum thickness. The spec requires at least eighteen gauge steel that is galvanized or rust-inhibited, meaning the base cannot be thinner than eighteen gauge. In sheet metal, thinner material has a higher gauge number, so twenty gauge would not meet the requirement, while thicker options like sixteen or fourteen gauge would still satisfy the condition. The key point is that eighteen gauge is the minimum thickness specified, so it’s the gauge you use to meet the requirement, with thicker gauges also acceptable if chosen.

The main idea is that the plaster ground base must have a minimum thickness. The spec requires at least eighteen gauge steel that is galvanized or rust-inhibited, meaning the base cannot be thinner than eighteen gauge. In sheet metal, thinner material has a higher gauge number, so twenty gauge would not meet the requirement, while thicker options like sixteen or fourteen gauge would still satisfy the condition. The key point is that eighteen gauge is the minimum thickness specified, so it’s the gauge you use to meet the requirement, with thicker gauges also acceptable if chosen.