ISO 12944 - Helping you select the right coating system

ISO 12944 - Helping you select the right coating system

Steel structures, from bridges and plant machinery to tanks and offshore platforms, are constantly at threat from their environment. Moisture, salt, chemicals and pollution all play a part in potentially corroding steel, degrading its overall performance, shortening its lifespan and potentially causing safety issues as well – all of which cost you money. The ISO 12944 standard is the internationally-recognised framework that specifies how to protect steel effectively through coating systems. At New Guard Coatings, we can help you maximise durability and save costs by supporting you to select the correct system for your specific requirements.

What Is ISO 12944?

ISO 12944 is an international standard developed by the International Organization for Standardization. Its purpose is to guide engineers, specifiers, contractors, and asset-owners on how to protect steel structures from corrosion using specific paint/coating systems. Key elements covered include:

• Classification of environmental exposure (how corrosive the environment is).
• Definition of coating durability classes (how long the coating should last under given conditions).
• Requirements for surface preparation (how clean or rough the steel must be before coating).
• Specification of what coating types, thicknesses, and layers are suitable under different exposure classes.
  
  

Corrosion Categories & Durability Ratings

Environmental Corrosion Categories describe the severity of the exposure depending on the final destination of your steel:

• C1 – Very Low: basically heated indoor spaces with minimal humidity (offices, similar).
• C2 – Low: rural environments, low pollution.
• C3 – Medium: urban or light industrial atmospheres.
• C4 – High: coastal zones or chemical plants.
• C5 – Very High: marine exposure, aggressive industrial conditions.
• CX – Extreme: fully submerged steel, immersion, very high chloride exposure (e.g. offshore).

Durability Ratings relate to the expected life of the coating system before major maintenance or beginning of corrosion. Sometimes this gets misinterpreted as the first time that any work needs to be done whatsoever, however it’s important to have an cleaning and maintenance schedule on an on-going basis, and this durability rating is the first time that significant work is likely to be required to be carried out.

 

Rating	Expected Life	Typical Use-Case
Low (L)	Up to 7 years	Minimal exposure, indoors, occasional moisture.
Medium (M)	7-15 years	More aggressive industrial or coastal but moderate conditions.
High (H)	15-25 years	Demanding environments—marine, heavy industrial.
Very High (VH)	Over 25 years	Offshore platforms, submerged exposures, or critical structures needing low maintenance over very long term.

               

 

It’s very important to match the correct exposure category with the correct durability rating. New Guard Coatings would glad to guide you through this process. Under specifying can lead to early corrosion and system breakdown, and over specifying can create unnecessary additional costs.

 

What a Certified Coating System Looks Like

Surface preparation - Preparation is always critical. Get the steel clean, remove rust, degrease, etc, and then correctly prepared the surface as per the specification with either manual / hand tools, or preferably by shot blasting.

Primer coat - apply a primer. For example, using anti-corrosion primers for steel or galvanised surfaces. Principally the primer’s job is to create adhesion of the whole coating system to the substrate.

Intermediate coats – if required, these build-up film thickness, providing corrosion resistance due to the thickness itself and sometimes improving impact or chemical resistance too, depending on the make-up of the product selected.

Topcoat – principally these provide the required aesthetic finish look to your steel, meeting any gloss or colour requirements. They are generally designed to protect from UV, abrasion and weather.

 

Why Use ISO 12944 Coating Systems?

• Proven performance under known standards. ISO 12944 gives you measurable, tested criteria so you can predict expected life.
• Reduced maintenance & downtime. Getting the system right reduces corrosion-related failures, large repairs, and the associated expenses.
• Compliance and specification. Many projects or regulatory bodies require ISO classification, as being certified helps with contracts, insurance and ensuring regulation requirements are all met.
• Tailored protection. You get to choose coatings appropriate for the exact exposure (from light indoor or rural to offshore immersions), and the required lifespan.

 

Here to help you!

Our team are always on-hand to guide and support you in selecting the correct coating system for your requirements; either pick-up the phone or send us an email and we’ll get back to you with an update within 2 hours.

Our close association and partnerships with some of the globe’s leading brands and coatings manufacturers means you get the best of both world – competitive access to and support from these leading brands, but with the back-up, flexibility and personal support that only a family business like New Guard can truly provide.

With over 150,000 litres of product stocked nationwide at our six UK depots, chances are we can get your selected coating system to you next-day in many instances, delivered via our own team giving you peace of mind that everything will get there in one piece! Or, if local to one of our branches, feel free to call in to discuss your requirements in-person over a coffee, and we can often have any order ready for you to away with you straight afterwards!