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
UKCW London to tackle sector’s most pressing issues
AI and skills development, ecology and the environment, policy and planning and more.
Managing building safety risks
Across an existing residential portfolio; a client's perspective.
ECA support for Gate Safe’s Safe School Gates Campaign.
Core construction skills explained
Preparing for a career in construction.
Retrofitting for resilience with the Leicester Resilience Hub
Community-serving facilities, enhanced as support and essential services for climate-related disruptions.
Some of the articles relating to water, here to browse. Any missing?
Recognisable Gothic characters, designed to dramatically spout water away from buildings.
A case study and a warning to would-be developers
Creating four dwellings... after half a century of doing this job, why, oh why, is it so difficult?
Reform of the fire engineering profession
Fire Engineers Advisory Panel: Authoritative Statement, reactions and next steps.
Restoration and renewal of the Palace of Westminster
A complex project of cultural significance from full decant to EMI, opportunities and a potential a way forward.
Apprenticeships and the responsibility we share
Perspectives from the CIOB President as National Apprentice Week comes to a close.
The first line of defence against rain, wind and snow.
Building Safety recap January, 2026
What we missed at the end of last year, and at the start of this...
National Apprenticeship Week 2026, 9-15 Feb
Shining a light on the positive impacts for businesses, their apprentices and the wider economy alike.
Applications and benefits of acoustic flooring
From commercial to retail.
From solid to sprung and ribbed to raised.
Strengthening industry collaboration in Hong Kong
Hong Kong Institute of Construction and The Chartered Institute of Building sign Memorandum of Understanding.
A detailed description from the experts at Cornish Lime.

























