Use this calculator to compare the initial and life-cycle cost of hot-dip galvanizing to one of 30+ other corrosion protection systems. Or, thanks to a recent addition, you can also compare the initial and life-cycle cost of a duplex system (paint over hot-dip galvanizing) to more than 30 paint systems alone (on bare steel).

On the following screens you will be prompted to enter specific details about your project. Based on the information you provide, the Life-Cycle Cost Calculator (LCCC) will generate a customized report detailing all costs associated with maintaining the structure over the desired project service life, including the time value of money.

All the financial equations used in the calculator are the same as those provided in the specification ASTM A1068-10 Standard Practice for Life-Cycle Cost Analysis of Corrosion Protection Systems on Iron and Steel Products.

Choosing a corrosion protection system is a critical step in the design of your project. The estimated annual cost of corrosion is a staggering 3% of the US GDP and the life-cycle cost of corrosion-related maintenance is two- to five-times the initial cost.

Data Sources

• Paint system costs (including surface preparation) and practical maintenance times: J. Helsel and R. Lanterman. (2021). Expected Service Life and Cost Considerations for Maintenance and New Construction Protective Coating Work. KTA-Tator, Inc.
• Metallizing costs (including surface preparation) and practical maintenance times: J. Helsel and R. Lanterman. (2021). Expected Service Life and Cost Considerations for Maintenance and New Construction Protective Coating Work. KTA-Tator, Inc.
• Hot-Dip Galvanizing costs: American Galvanizers Association National Survey (2021)
• Hot-Dip Galvanizing time to first maintenance (corrosion rates): Average values from Table 1 of ISO 14713-1:2017, Zinc coatings — Guidelines and recommendations for the protection against corrosion of iron and steel in structures — Part 1: General principles of design and corrosion resistance.
  Paint system service environments: Table 1 of ISO 12944-2:2017, Paints and varnishes — Corrosion protection of steel structures by protective paint systems (Part 2: Classification of environments).
• Hot-Dip Galvanizing service environments: Table C.1 of ISO 9223:2012, Corrosion of metals and alloys — Corrosivity of atmospheres — Classification, determination and estimation.

About Duplex Systems

When painting or powder coating over hot-dip galvanizing (known as a Duplex System), the two coatings work together to increase overall longevity and provide a more sophisticated level of corrosion resistance known as the synergistic effect. The hot-dip galvanized coating prevents under film corrosion of the paint or powder coating system, which increases the longevity of the paint system and extends paint maintenance cycles at least 50% in comparison to the same paint system applied over bare steel.

The overall time to first maintenance of a duplex coating system is a factor of 1.5 to 2.3 times the sum of the individual service lives for hot-dip galvanizing or painting alone. When discussing the synergistic effect, the value for the multiplication factor (1.5 to 2.3) is selected based on the corrosivity of the environment.

Reference: Van, Eijnsbergen J. F. H. (1994). Duplex Systems: Hot-Dip Galvanizing Plus Painting. Amsterdam: Elsevier.

To obtain a meaningful cost comparison (and in the absence of multiplication factors which directly correlate to ISO service environments C1-C5), the practical maintenance time of a paint system applied over hot-dip galvanizing within the AGA Life Cycle Cost Calculator is defined as 2 times the practical maintenance time for the same paint system applied over bare steel.

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Copyright 2021 American Galvanizers Association. The material provided herein has been developed to provide accurate and authoritative information about after-fabrication hot-dip galvanized steel. This material provides general information only and is not intended as a substitute for competent professional examination and verification as to suitability and applicability. The information provided herein is not intended as a representation or warranty on the part of the AGA. Anyone making use of this information assumes all liability arising from such use.