How Long Does Galvanized Steel Last Underground?

Top 10 Most Surprising Underground Bunkers of All Time


Galvanized steel is a material that has been widely used in various industries due to its durability, strength, and corrosion-resistant properties. However, one question that often arises is how long does galvanized steel last underground? In this article, we will discuss the factors that affect the lifespan of galvanized steel when buried underground.

The Basics of Galvanized Steel

Galvanized steel is a type of steel that has been coated with a layer of zinc to protect it from rust and corrosion. This process is called galvanization, and it involves immersing the steel in a bath of molten zinc. The zinc forms a protective layer that prevents the steel from coming into contact with moisture and oxygen, which are the two main causes of rust.

The Lifespan of Galvanized Steel

The lifespan of galvanized steel when buried underground varies depending on several factors. The first factor is the thickness of the zinc coating. The thicker the coating, the longer the steel will last. The second factor is the quality of the zinc coating. If the coating is of poor quality, it will not provide adequate protection, and the steel will corrode faster.

The Soil Conditions

Soil conditions also play a significant role in the lifespan of galvanized steel when buried underground. The pH level of the soil, the presence of certain chemicals, and the moisture content of the soil can all affect the rate of corrosion. Soils with a pH of less than 6 or greater than 8 are considered acidic or alkaline, respectively, and can cause galvanized steel to corrode faster.

The Type of Soil

The type of soil also affects the lifespan of galvanized steel. Sandy soils are more porous and allow water to drain more easily, which can help prevent corrosion. Clay soils, on the other hand, retain moisture and can promote corrosion. Additionally, soils that are rich in organic matter can also accelerate the corrosion process.

The Importance of Maintenance

Regular maintenance is essential to ensure the longevity of galvanized steel when buried underground. This includes inspecting the steel for signs of corrosion, repairing any damage, and applying a fresh coat of zinc if necessary. In some cases, it may be necessary to replace the galvanized steel altogether.


In conclusion, the lifespan of galvanized steel when buried underground depends on several factors, including the thickness and quality of the zinc coating, soil conditions, and the type of soil. Regular maintenance is also essential to ensure the longevity of the steel. By taking these factors into consideration, you can maximize the lifespan of your galvanized steel and ensure that it performs as intended.