What Is Prepainted Galvanized Steel Coil
[edit] Introduction
Prepainted galvanized steel coil is a kind of colour coated steel coil (PPGI coil). It uses galvanized steel as the base metal. The zinc layer offers strong corrosion resistance. Plus with painting, it is more durable than galvanized steel.The metallic coated steel then experiences some cleaning procedures, pre-treatment solutions and ultimately gets multiple layers of organic coatings, including laminates, vinyl dispersions, and paint. This continuous technique of applying different coatings is referred to as coil coating. Therefore, the steel coil doesnt require painting or finishing when employed in finished products.
[edit] PPGI vs. PPGL
To start with, they use different substrates. PPGI uses galvanized sheets as being the base metal. They have a zinc coating throughout to prevent moisture, rust, and corrosion from destroying the steels surface.The substrate for prepainted galvalume steel is a combination of 1.6% silicon, 43.3% zinc, and 55% aluminum. The substrate influences their applications which further differentiates the 2 kinds of steel.
The service life of these two types of steel also varies because of the substrates. The substrates prolong the steels service life by protecting them from rust and corrosion. Zinc is the perfect substrate for safeguarding steel from rust. PPGI has near to 99% zinc within its substrate, but PPGL only has 43.3%. This gives PPGI a longer service life in comparison with PPGL. Although aluminum and silicone are great alloys, they arent the best at protecting steel from corrosion or rust. They eventually wear out with time, thus exposing the steel to moisture that leads to corrosion.
There is also a difference between the weight of PPGI and PPGL. Aluminum, zinc, and silicone substrates are heavier than zinc substrates. As a result PPGL is heavier than PPGI. However, many industries prefer PPGI due to its ability to withstand rust and corrosion. The strength of the steel is more or less similar to PPGL. A PPGL sheet covers around 3% extra space compared to a PPGI sheet.
[edit] Related articles on Designing Buildings
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Planning condition discharge in England and Wales
A brief exoplanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.