Z275 Color Coated Steel Coil with 20 Year Color Retention Warranty

Z275 Color Coated Steel Coil with 20 Year Color Retention Warranty

A warranty is only meaningful when the substrate underneath it can support the promise. This coil uses a Z275 galvanized base, meaning 275 grams of zinc per square metre, which gives a substantially thicker sacrificial layer than the Z120 and Z180 material commonly sold at the same price point. On top sits a polyester coating system with UV stabilizers and anti chalking pigments that has been qualified against outdoor exposure data, which is what allows us to issue a written 20 year color retention commitment instead of a verbal assurance.

We separate two things in the warranty document: color and gloss retention on one side, and perforation from corrosion on the other. Buyers often assume one number covers both. It does not, and confusing them is the most common reason a claim gets rejected years later.

Specification Data

What the Warranty Actually Covers

• Color shift beyond the agreed dE limit under normal exterior exposure.
• Chalking that exceeds the agreed rating scale on the sun facing surface.
• Peeling or blistering caused by a coating defect, not by site damage.
• Exclusions stated plainly: cut edge corrosion, chemical attack, damage from transport or installation.
• Claim procedure in writing, with a site inspection step and a defined response window.

Projects That Need This Coil

• Buildings with a contractual facade warranty period
• Public infrastructure where the client demands written guarantees
• Export projects requiring documentation at tender stage
• Roofing packages bundled with a maintenance schedule

Buyer Questions

Is the warranty transferable to the end client?

Yes, when the coil is traced to the project through the coil number on our label. That is why we print the heat number and coating batch on every coil and keep the record for the full warranty term.

What invalidates the claim?

Cut edge corrosion on an unsealed edge, contact with aggressive chemicals, mechanical damage from fixing tools, and installation outside the stated temperature range. We list these on page one of the document rather than burying them.

Does Z275 matter if the coating is intact?

It matters at every cut edge, drilled hole and scratched area. Z275 slows the corrosion that starts where the paint stops, which is where most real world failures begin.

Can you supply a sample for approval first?

Yes. We send a coated sample panel with the measured film thickness and the batch reference, so the approval is against physical material rather than a screen image.

Packing and Traceability

Coils are wrapped in PVC film with paper interleaving, strapped on wooden pallets and labelled with heat number, coating batch and film thickness. The warranty register links each coil number to its production date, so a claim can be checked against the actual run rather than a purchase invoice.

Coating thickness matters more than coating brand in service: Top 20 - 25 micron, primer 5 micron. Below roughly 20 micron total build, UV exposure in strong sun starts to chalk the surface within a few years, and the colour drifts before the steel itself shows any problem.

Formability is specified as T bend 2T on 0.5 mm gauge. This determines whether the strip can be roll formed and folded at the job site without cracking the coating over the bend radius, which is the most common cause of premature coating failure on roofing panels.