DIY Builds
Photo by Lokman Sevim Pexels Logo Photo: Lokman Sevim

How long does galvanized steel take to rust?

The zinc coating of hot-dipped galvanized steel will last in the harshest soil is 35 to 50 years and in less corrosive soil 75 years or more. Although humidity affects corrosion, temperature itself has less of an impact.

How many cinder blocks do I need for a 10X12 shed?
How many cinder blocks do I need for a 10X12 shed?

16 Wood Shed Foundations Shed Size Number of Blocks 8X12 12 10X10 14 10X12 16 10x16 20 4 more rows • Oct 17, 2019

Read More »
Should I use landscape fabric under gravel?
Should I use landscape fabric under gravel?

Should landscape fabric go under gravel? Yes. Putting landscape fabric under gravel isn't a requirement, but it is recommended. When used under...

Read More »
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »

Galvanized steel is corrosive to all metals except lead, tin, zinc and aluminum. Although it does not last infinitely, galvanized steel is the unparalleled corrosion-resistant metal. It is worth noting however, that applying a protective coating such as paint to galvanized steel will alleviate the problems caused by corrosion of the protective zinc coating. Galvanized steel has been used for almost 2,000 years because of its unrivaled ability to last a very long time and resist rust. Hot dipped galvanized steel and electroplated galvanized steel are made using different methods and their zinc galvanized coatings corrode completely differently. Learn about these galvanizing processes (here) and how zinc corrosion varies between them (here) . Yes, galvanized steel resistance to rust corrosion depends largely on the type and thickness of the protective galvanized zinc coating, but the type of corrosive environment is also a critical factor. Factors that rust and corrode galvanized steel:

How Long Does Galvanized Steel Last

So how long does it take for a handy new galvanized steel bucket to rust and corrode into a useless heap of metal? It takes a long time. A galvanized steel bucket (produced with any method) can last practically forever if it's gently used and kept dry and out of the rain. But for those galvanized buckets and tubs destined to become garden planters, landscape decorations, animal feeders, and farm water buckets corrosion is inevitable. Galvanized steel intended for prolonged outdoor use should be hot-dipped galvanized steel; which commonly lasts for about 70 years in many different environments. Table 1 below predicts how long galvanized steel will last based on a 30 month corrosion study of environmental factors like wetness, humidity, and air pollutants in 2004. Table 1. Prediction of When Zinc Layer will be Consumed on Galvanized Steel Galvanized Steel kept in the wet or soaked environments 10 Years with a relative humidity of 100% 34 Years with a relative humidity below 60%. 211 Years The corrosion resistance of zinc coatings is determined primarily by the type and thickness of the coating but, varies with the severity of environmental conditions exposed to (as in the table above). Hot dipped galvanized zinc coating resistance to corrosion depends primarily on a protective film (patina) formed on its surface.

Types of galvanizing; compare the properties of galvanization methods.

Does galvanized zinc rust; learn how a hot-dipped zinc coating corrodes to form a patina layer that can protect the zinc metal underneath for upwards of 75 years. Zinc corrosion products of hot-dip galvanizing build-up (creating a patina layer) and insolubly cling to the metal in many environments. Thus, the corrosion rate of hot-dip galvanized steel may slow as time progresses. The type of zinc galvanization and how that process controls the way in which the galvanized steel corrodes must be understood first. The environments, elements, and conditions that any given type of galvanized steel is exposed to, nevertheless, indeed determines how long it will last before corrosion.

What is the rough opening for a 12 foot garage door?
What is the rough opening for a 12 foot garage door?

The rough opening's width should be three inches longer than the door, measured between the left and right edges. So, in a 12-foot wide garage...

Read More »
Why are doors so low in England?
Why are doors so low in England?

Many of the townhomes, or terraced buildings as they're known there, were built in the 19th and 20th centuries. It was easier to make sure such...

Read More »
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »

A 1926 study of galvanized steel corrosion in industrial, rural and sea regions found: At any one location the life of the zinc coating is directly proportional to its thickness. The most rapid corrosion occurred at the highly industrial locations, and the least rapid at the rural and more arid locations (9). The handy chart below (from American Galvanizers Association) illustrates how long galvanized steel will last before corroded areas should be maintained to prevent further deterioration. Want to learn how to refinish galvanized steel? Click here. Put another way, this chart shows how long it takes for galvanized steel to rust in different environments. The thicker the zinc coating the longer galvanized steel will last without corrosion. The thickness of zinc is displayed along the horizontal axis (8). As in the chart below and noted in the 1926 study, for each location the corrosion rate is essentially constant with time (9).

Chart 1: Time to first sign of corrosion in various environments

The environments below are listed from the most corrosive to the least corrosive:

Industrial Environments:

Most city and urban areas as examples of urban environments.

Generally, the most aggressive corrosive environment.

Sulfide and phosphate air pollution, from point sources like automobile exhaust, cause galvanized zinc coating consumption.

Tropical Marine Environments

Regions where the temperature, if ever, falls below freezing.

Humidity is high and chlorides from nearby water are present in air.

Almost as corrosive as industrial environments

Warm temperatures increase the activity level of corrosion elements on the surface of the galvanized zinc. Proximity to the coast, wind direction and wind speed also influence the rate of corrosion

Temperate Marine Environments

Lower temperatures and humidity make temperate marine environments less corrosive to their tropical counterparts.

Suburban environments

Less corrosive than industrial areas

Residential perimeter communities outside urban areas and cities.

Rural Environments

Least aggressive corrosive atmosphere

Air and rain in rural regions contain relatively low levels of sulfur and other corrosive emissions.

What's the best base for a garden shed?
What's the best base for a garden shed?

In most cases: Gravel is the best shed foundation, especially for portable buildings that come with a wood floor. Concrete is the ideal foundation...

Read More »
How do you weatherproof a wooden pallet?
How do you weatherproof a wooden pallet?

If you want to weatherproof wooden pallets, you need to use varnishes or finishes which will make it last longer outside. Packing and distribution...

Read More »
Are shed plans easy to follow?
Are shed plans easy to follow?

These are! They guide you every step of the way to complete your dream shed.

Learn More »
What is the goal post called?
What is the goal post called?

uprights In both sports, the goal structure consists of a crossbar suspended 10 feet (3.0 m) off the ground and goal posts (colloquially known as...

Read More »
Can I build my own shed?
Can I build my own shed?

Yes, with the right plans you can build your dream shed.

Learn More »
Do I need a membrane under my shed?
Do I need a membrane under my shed?

Excess water outside the shed must have an escape route away from the building. The foundation should contain a damp-proof membrane which should be...

Read More »