College

Galvanized metal lath is metal lath coated with which material?

1) Tin
2) Copper
3) Zinc
4) Nickel

Answer :

Galvanized metal lath is metal lath coated with 3) zinc.

Galvanization is a method of protecting iron or steel from corrosion by coating it with a thin layer of a more easily oxidized metal. In the case of galvanized metal lath, the coating material used is zinc.

There are two main processes used for galvanizing metal: hot-dip galvanization and electro-galvanization:

  1. Hot-Dip Galvanization: This involves immersing the metal in molten zinc, creating a thick and robust zinc coating. This type of galvanized metal is highly resistant to corrosion and is typically used for outdoor applications.

  2. Electro-Galvanization: This method uses electroplating to apply a thinner zinc layer to the metal. The zinc coating from electro-galvanization is generally shinier and more uniform but less durable than the hot-dip method. It's often used for indoor applications where the metal is less exposed to harsh environmental conditions.

Final answer:

Metal lath is coated with zinc during the galvanization process to protect it from corrosion, providing both prophylactic and cathodic protection. So the correct answer is option (3).

Explanation:

Galvanized metal lath is metal lath coated with a thin layer of zinc. This method, known as galvanization, is a standard process used to protect iron and other metals from corrosion. Zinc provides both prophylactic protection, shielding the metal beneath from moisture and oxygen, and cathodic protection, as zinc will oxidize before the iron does, acting as a sacrificial anode. Zinc, in the form of a coating on the metal lath, acts as a sacrificial layer, corroding preferentially to protect the underlying metal substrate from rust and deterioration.

The use of galvanized metal lath is prevalent in projects where a reliable and corrosion-resistant substrate is required to support the application of plaster or stucco finishes. This galvanization process ensures that the metal lath remains structurally sound and resilient, even in challenging environmental conditions, contributing to the overall integrity and longevity of the construction project.