How to choose the right

A guide in accordance with ISO 12944 standards

paint systems to protectyour steel structure

ISO 12944

IntroductionAll steel structures, due to the nature of steel, will be affected by corrosion when it meets water and oxygen.

Once steel is oxidised, it can occupy six times the volume of the original material, and consequently dramatically affect the structure. This makes it vital to protect steel as best as possible to limit damaging consequences and to protect the longevity of a structure.

To ensure you understand which Pronto paint systems are best suited to protect a given steel structure, we have written out this simple guide, in accordance with the latest edition of the ISO 12944 standards.

The ISO 12944 standard is an international standard designed to assist anyone involved in the design and construction of steel structures. We have created this guide in accordance with the ISO 12944 standards to help explain the types of Pronto paint systems available for steel structures depending on different environments, surfaces and durability.

This guide is designed to help you choose the right paint based on your requirements.

ABC

Select the Environment

Select the Durability

Select a System

First and foremost, before selecting a paint it is important to understand the conditions the structure operates in, and how exposed to corrosivity it may be.

Secondly, you must select how long you want your paint system to last before you do any major maintenance to the paint work.

This can vary depending on the structures exposure to the following:• Humidity • Elevated temperatures• Chemicals• UV radiation • Mechanical works

This table gives you an idea of the corrosive environment of a given steel structure.

Most projects take place in and around the city, this is normally classified as a C3 environment.

Corrosive Environment(ISO 12944-2)

Typical EnvironmentsExterior Interior

C1 - Very LowHeated buildings with clean atmospheres. e.g. offices, shops, hotels and schools

C2 - Low Atmospheres with low level of pollution. Mostly rural areas.

Unheated buildings where condensation may occur. e.g. sports halls, warehousing

C3 - MediumUrban and Industrial atmospheres, moderate sulphur dioxide pollution. Coastal areas with low salinity.

Production rooms with high humidity and some air pollution, humidity and some air pollution. e.g. food processing plants, laundries, breweries and dairies

C4 - High Industrial areas and coastal areas with moderate salinity.

e.g. chemical plants, swimming pools, coastal boatyards

C5I - Very High (Industrial) Industrial areas with high humidity and aggressive atmospheres.

Buildings or areas with almost permament condensation and with high pollution.

C5M - Very High (Marine) Coastal and offshore areas with highly salinity.

Buildings or areas with almost permament condensation and with high pollution.

A Select the Environment

B Select the durability of the paint job

System Durability Years to first Major Maintenance

Low Less than 5 years

Medium 5 to 15 years

High More than 15 years

Depending on the quality of the paint, you will have to maintain the paint job more or less often. ISO 12944 specifies a range of time frames.

The above systems are based upon a low alloy carbon steel substrate.

Corrosive Environment System DurabilityLow Medium High

C1 P10 P10 P10

C2 P10, P11, P50 P11, P50 P11, P51

C3 P11, P50, P56 P11, P51, P56 P52, P56

C4 P53, P55 P53, P55 P54, P55

C5I P55 P55 -

C5M P55 P55 -

Pronto System Product ReferenceDry Film Thickness

(microns) ISO 12944-5 System Ref

Product System

P10 200:026 202:000

QD Industrial Primer QD Gloss Finish

50 30

80 A2.01

P11 450:004 ProTect Vinyl 160 160 A3.05

P50 100:006 360:000

2 Pk Epoxy Primer 2 Pk Poly Finish

80 40

120 A2.06

P51 100:006 360:000

2 Pk Epoxy Primer 2 Pk Poly Finish

80 80

160 A2.07 A3.08

P52 100:006 360:000

2 Pk Epoxy Primer 2 Pk Poly Finish

140 60

200 A3.09

P53 100:006 360:000

2 Pk Epoxy Primer 2 Pk Poly Finish

160 80

240 A4.08

P54 100:006 360:000

2 Pk Epoxy Primer 2 Pk Poly Finish

200 80

280 A4.09

P55103:026 100:006 360:000

2 Pk Epoxy Zinc Rich 2 Pk Epoxy Primer 2 Pk Poly Finish

60 130 50

240

A4.12 A5I.04

A5M.05

P56103:026 100:006 360:000

2 Pk Epoxy Zinc Rich 2 Pk Epoxy Primer 2 Pk Poly Finish

60 50 50

160

A3.11

The Pronto paint system you choose will depend on the corrosive environment the said structure lives in, and the preferred durability time frame before the first maintenance is needed.

Information about the Pronto paint systems mentioned above – all these products are in accordance with the ISO 12944 standards

C Select a Pronto paint system

This table indicates what types of Pronto paint systems you should be looking at depending on your requirement.

For example, if the structure you wish to paint is located in a C3 environment and you wish to not have to do any maintenance for at least the next 5 years, you will be looking at Pronto paint systems P11, P51 or P56. For more information about these systems please refer to the last table.

www.prontopaints.co.uk info@prontopaints.co.ukT: 01246 857 777 F: 01246 857 978