Roofing buyers weighing AZ150 galvalume against Z275 galvanized are really choosing between two protection philosophies: aluminium-zinc barrier life versus pure zinc sacrificial protection. Both are premium coating classes; they win in different situations.
Head-to-Head Comparison
| Parameter | AZ150 Galvalume | Z275 Galvanized |
|---|---|---|
| Coating composition | 55% Al, 43.4% Zn, 1.6% Si | ~100% zinc |
| Coating mass | 150 g/m² | 275 g/m² |
| Bare outdoor life (C3) | 25-40+ years | 20-30 years |
| Cut-edge protection | Weaker (less sacrificial zinc) | Stronger |
| Contact with mortar/concrete | Not recommended | Acceptable |
| Heat reflectivity | Higher (brighter surface) | Standard |
| Typical price | +USD 20-40/ton over Z275 | Base |
Choose AZ150 When
The roof is long-span, unpainted or lightly painted, in a hot or coastal climate, and panels are thin (0.30-0.55 mm). Galvalume barrier oxide simply lasts longer per gram of coating — which is why most African and Middle East long-span roofing has moved to aluzinc. Full details in our galvalume specifications and the AZ100 vs AZ150 guide.
Choose Z275 When
Panels are field-cut heavily, edges stay exposed, the sheet touches concrete or mortar, or the local standard explicitly calls for G90. Zinc sacrificial action heals scratches and cut edges better than galvalume.
The Practical Answer for Distributors
Most of our roofing customers stock AZ100/AZ150 aluzinc for premium long-span lines and Z180-Z275 galvanized for economy corrugated lines. Container mixing is possible at 25 tons per specification. Compare the broader question in galvalume vs galvanized for roofing.
FAQ
Which lasts longer, AZ150 or Z275?
On intact surfaces, AZ150 typically outlasts Z275 by 1.5-2x in neutral and marine atmospheres. At cut edges and scratches, Z275 degrades more gracefully.
Can both be used as PPGI/PPGL substrate?
Yes — painted galvalume is sold as PPGL, painted galvanized as PPGI. The same coating logic applies underneath the paint.
What is the price difference right now?
It moves with LME aluminium and zinc. Send your spec to sales for a live FOB Tianjin quote — we reply within 24 hours.
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