Chromadek® is lighter and stronger than any other roofing material, providing roofs of up to 80% lighter than those using concrete tiles. This saves on the roof structure, construction time and equally important - cost.
In light of certain competitors' product failures, it is clear that all colour-coated steel sheeting does not comply with the design requirements for structural roofing materials. Because of the dominance of Chromadek®, the name is being used generically for pre-painted roof sheeting. Chromadek® sheeting is imprinted with "ArcelorMittal South Africa Chromadek®" at regular intervals to mark it as the REAL thing.
Chromadek® offers great versatility for roofing and cladding applications. South African architects use Chromadek® in a variety of roofing and cladding projects ranging from churches, shopping malls, factories, warehouses and airports to luxury eye-catching homes and large housing estates.
Chromadek® is exceptionally colourfast. Warrantees are given on application, subject to certain conditions. The African Heritage Colour Range of 14 exciting colours captures the essence of the African environment and reflects the continent's unique colours and hues and allowing designers the freedom of expression.
Chromadek® is available as either Chromadek® Standard or Chromadek Ultim® designed for exposure and use in different atmospheric conditions:
Is intended for use under rural, Industrial (mildly chemically polluted) or moderate marine conditions.
Comprises a Z200 hot-dipped galvanized substrate pre-primed with a primer (Dry film thickness (DFT) of 5µm) and finished with a final paint coat (DFT of 18 - 22µm) on the top surface.
A single backing coat (DFT of 8µm) is normally applied to the reverse side of the sheet.
Is intended for heavy industrial or marine conditions,
Comprises a Z275 hot-dipped galvanised substrate, pre-primed with a chrome free primer (DFT of 20µm) and finished with a final coat (DFT of 18 - 22µm) on the top surface, giving a total dry film thickness of 38 - 42µm.
The reverse surface is coated with a 10µm corrosion resistant chrome free primer and a 10µm top surface paint system.
Steel is generally regarded as a rigid material offering only strength. This is not true of ArcelorMittal South Africa’s galvanised sheet used as substrate for Chromadek®. It is readily formable which makes it eminently suitable for a wide variety of end-uses in the building industry. The formability of the substrate is matched by the flexibility of the paint system – two characteristics desired by architects, profilers and developers.
At ArcelorMittal South Africa’s Vanderbijlpark paint line, laboratory personnel conduct exhaustive tests on every coil of Chromadek®to ensure its formability and durability. The T-bend test is used to determine the resistance of the paints to cracking and/or detachment from the substrate. It gives an indication of the flexibility and adhesion of paint when it is deformed by bending through 180 degrees. No cracking and delamination of the paint is permissible. The primer and top coat on both sides of the sheet are tested for wet film and dry film thickness as well as for hardness and gloss after curing.
Every coil of Chromadek®is also subject to a reverse impact test to test adhesion and a solvent rub test to ensure proper curing – an important factor contributing to colour fastness.
The superior corrosion resistance, of Chromadek® reduces maintenance costs as it does not require repainting for many years after installation.
The appearance and properties of Chromadek® and Chromadek Plus® can be safeguarded by proper handling, storage, installation and maintenance procedures. Chromadek® should be stored in a dry, well-ventilated area, clear off the ground. Sheeting should not be allowed to get wet while still bundled or nestled in stacks. If a pack does become wet, the sheets should be separated as soon as possible and the surfaces dried with a cloth. Sheets should then be stacked so that free air circulation completes the drying process.
When handling Chromadek® on site, care should be taken not to damage the surface finish.
If the paint surface should become scratched - either during installation or later on - specially formulated air-drying touch-up paints are available. The surface would first have to be cleaned of any dirt, grease or chemical pollutants that might be present. Keep in mind that the UV resistance of air-drying touch-up paints cannot match the UV resistance of the oven-cured Chromadek® paint systems and the use of touch-up paints should be kept to a minimum.
When using Chromadek®, you are assured of excellent technical back-up.
To keep your Chromadek® roof in pristine condition for as long as possible, surfaces should periodically be washed down with water and a mild detergent to prevent the accumulation of corrosive debris such as leaves, dirt and pollution fallout. This is especially recommended for Chromadek® and Chromadek Plus® in a corrosive environment.
Two of the colours of the Chromadek® range (See Data Sheet C1.4), Charcoal Grey and Dark Dolphin, are produced by utilizing an advanced thermal technology paint system. This advanced paint system incorporates a heat reflective pigment into the paint providing up to 8°C cooling and improved durability. The durability of an exterior coating is measured according to its capability of maintaining gloss, colour and film integrity.
The heat reflective pigments present in Heat Reflective Chromadek® are chemically inert and highly stable. Heat Reflective Chromadek® reflects more of the sun’s energy to prevent the coating from absorbing energy directly resulting in less heat build up and indirectly resulting in longer life-cycles (less fading).
In order to understand how Heat Reflective Chromadek® works it is essential to understand the nature of energy with which coatings act.
Heat Reflective Chromadek® offers the following benefits:
a) Increased durability:
- Increased gloss retention.
- Improved colour stability (less fading).
- Sustainable film integrity.