The annual cost of preventable, atmospheric corrosion of steel products is estimated to be 3-4% of the gross national product (GNP). For the United States, that represents $290 billion. The Life-Cycle Cost Calculator (LCC) was specifically developed to prevent you from designing your structure/project to contribute to that total cost. The LCC Calculator is for use on structures/projects that have atmospheric exposure only. It is not applicable for liquid or soil exposure, as those corrosion kinetics are quite different than atmospheric.
Use the links to the left to familiarize yourself with the LCC prior to beginning. When ready, use the Next button to begin.
Copyright © 2007 American Galvanizers Association. The material provided herein has been developed to 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 risk arising from such use.
Selection of a corrosion protection system by an architect, engineer, or project owner is often made based on the priorities of initial price, historical performance, established specifications, and/or personal preference, in that order. While all are important elements of the decision-making process, the structure/project’s total cost (initial + maintenance) for the duration of the design life, aka life-cycle cost (LCC), is often two to five times greater than the initial cost. This suggests that the first priority in the analysis should be the determination of LCC.
Summing up all costs associated with the initial application and maintenance of a corrosion protection system over the life of a structure/project,
the LCC Calculator is a tool to assist you with the decision as to what system is most economical in the long-run. The calculation of LCC
is not simple because the value of money over time changes. So, the calculation of LCC for maintenance must consider the impact inflation
has on future expenditures and conversely the lost opportunity to invest money at an interest rate over the life of the project. The
Life-Cycle Cost Calculator does exactly that. It uses established financial industry equations for net present value (NPV) and net future value (NFV), utilizes a database of initial cost data for 40 unique
corrosion protection systems (paint, hot-dip galvanizing), and input you provide that is specific to your structure/project. The output is provided in terms of a total job cost and an average annual equivalent cost (AEAC).
The source of the LCC Calculator cost database for paint is information captured in a survey conducted by KTA Tator, Inc.,
consultant to the paint industry. The survey results were published in the paper #6318 Expected Service Life and Cost Considerations for
Maintenance and New Construction Protective Coating Work (Helsel, Melampy, Wissmar), presented at the 2006 National Association of Corrosion
Engineers conference. Durability data, i.e. time to maintenance and time to full repaint in the paper is based on actual in-field performance.
Cost data for hot-dip galvanizing is based on a 2006 national survey conducted by the American Galvanizers Association (AGA) and durability data
is based on models that were developed using statistical methods, neural network technology and an extensive worldwide corrosion database.
Input that you will provide includes the unit of measure (English v. Metric), currency designation, coating system you are considering
(e.g. two-coat epoxy zinc/polyurethane), surface preparation method (cleaning grade), project size (tons or square feet), application method, project design
life, and service environment (e.g. severe heavy industrial C5-1).
The objective output of the LCC Calculator will be a direct comparison of the calculated, initial project cost of your chosen corrosion
protection system to the initial cost of hot-dip galvanizing as input by you or from the database’s national average cost for hot-dip
galvanizing. More importantly, the output will provide a comparison of the life-cycle cost, based on your input of opportunity cost
interest rate and projected inflation rate.
This direct comparison should in most cases simplify the selection of the most economical corrosion protection system.
The cost of coatings materials, preparation of the steel surface, and in-shop and field application is residing in the database that drives the calculations of both initial cost and life-cycle cost, as is the time to touch-up, maintenance painting, and full repaint. But as the LCC Calculator sequences from page to page, you will be required to provide information from "pull-down" menus.
You should have the following data available prior to starting:
- Currency in which you would like the output to be presented
- Coating type for primer, intermediate (if applicable), and topcoat (if applicable) (e.g. inorganic zinc primer, epoxy intermediate coat, and and polyurethane topcoat)
- Design/expected life of the project
- Service environment per ISO 12944-2 Classification of Environments (e.g. C3 medium - urban industrial atmospheres, moderate sulfur dioxide pollution, coastal areas with low salinity)
- Structural member composition of the project (e.g. medium structural, defined as those having 200 ft2 per ton)
- Surface preparation to be used (e.g. SP-10 Automated or SP-6 with Expendable Abrasives)
- Shop and field application of the paint
- Spray or brush application
- Paint material type (e.g. one-pack or two-pack)
- Total size of the project in square feet or tons
- Cost of hot-dip galvanizing or elect to use the U.S. national average
- Inflation rate to use to determine the true cost of future maintenance
- Interest rate to use to calculate the opportunity cost
Average equivalent annual cost (AEAC): the entire stream of present and future costs converted to a net present value and distributed in equal amounts over the project’s/structure’s service life. AEAC = NPV [i(1+i)n/(1+i))n-1] where i = interest rate and n = service life in years
Blast surface preparation: cleaning of the surface to SSPC-SP 6 “Commercial Blast” or SP 10 “Near White Blast”
Cleaning grade: extent to which the steel surface is prepared prior to the coating application; generally identified according to SSPC grades
Dry film thickness (DFT): the coating thickness after complete drying
Full repainting: total coating removal and replacement performed at the end of the time interval that includes the maintenance repaint time + 50%
Hand/Power surface preparation: cleaning of the surface to SSPC-SP 3 “Power Tool Cleaning” or SP 2 “Hand Tool Cleaning”
Hot-dip galvanizing: process of applying a zinc coating to fabricated iron or steel material by immersing the material in a bath consisting primarily of molten zinc. The zinc coating provides both barrier and cathodic corrosion protection
Life-cycle cost: the sum of initial corrosion protection system costs and all maintenance costs incurred during the service life of the project. Life-cycle cost may be expressed in net present value (NPV) or average equivalent annual cost (AEAC)
Maintenance painting: spot prime and full coat painting performed at the end of time interval that includes the practical service life time + 33%
Net future value (NFV): the current cost with inflation included, i.e. how much maintenance will cost, in inflated dollars in the year scheduled. NFV = Current Cost [1+i]n where i - inflation and n = service life in years
Net present value (NPV): the present worth of the inflated cost (NFV) in monies today invested at current interest rates. NPV = NFV (1/(1+i)n) where i - interest rate and n = service life in years
Practical service life: the time until 5% to 10% coating breakdown occurs and active rusting of the substrate is present
Service environment: the atmospheric conditions that exist at the site of the project, expressed in terms of rural, urban, industrial, and marine; based on the level of aggressive contaminants/pollutants such as
chlorides, sulfur dioxide, and salinity
Size of job multiplier: applied to the total field and shop costs
Structure multiplier: applied to the field labor cost to account for height of the structure; differs for simple and complex structures
Touch-up painting: spot repair performed on the structure at the point in time designated as the practical service life
To begin, use the Next button in the right hand corner of the screen.
The Next button will take you to the next screen after you have input the required information.
The Previous button will take you to your previous screen.
To start over, you must wait until you are at the end of the application, or hit the Previous button until you are back at the beginning.