Oct 30, 2026
|
Material |
3 years |
5–8 years |
Beyond 10 years |
|
Coated steel sheet |
Rust at cuts and drill holes |
Spreading rust, coating peel |
Wholesale replacement |
|
GRP roof light |
Surface yellowing |
Chalking, exposed fibre, embrittlement |
Severe transmission loss, replacement |
|
PC roof light |
Essentially unchanged |
Slight yellowing with UV layer |
Still serviceable, gradual transmission loss |
The failure mechanisms differ: steel corrodes electrochemically, GRP degrades its resin, and PC mainly photo-oxidises — and photo-oxidation is precisely what a UV co-extruded layer controls.
Salt spray, which is the coastal concern; dilute acids and alkalis in short contact; water and humidity, since PC does not absorb water; and most inorganic salt solutions found in industrial settings.
Suppliers often omit this, and it is where incidents originate: strong alkalis at high concentration cause surface attack and stress cracking; ammonia and amines crack it quickly; ketones, esters and aromatic hydrocarbons — acetone, thinner, toluene — dissolve or craze it; prolonged contact with concentrated alcohols swells and whitens it; and chlorinated disinfectants left standing cause fine surface cracks, common in cold-store cleaning.
So "does not rust" is true; "resists all chemicals" is not. For chemical plants or frequently washed areas, list the contact media first.
Illustrative, not a quotation: a coated steel roof light costs less initially but needs refurbishment around year five, and with scaffolding, labour and downtime that typically exceeds half the original installed cost. PC sheet costs 30–50% more up front and needs essentially no maintenance within ten years. Two refurbishments usually exceed the original price difference, before counting lost production and the hazard of a corroded roof light collapsing.
Use stainless or coated screws and washers — the panel will not rust but the fastener will, and it will leak. Keep dissimilar metals apart, since copper or steel in contact with aluminium profiles drives galvanic corrosion. And seal cut edges and drilled holes: an open multiwall end lets salt spray and dust into the flutes.
Can PC be used on offshore platforms? Salt spray is not the issue; assess UV intensity, wind load and cleaning regime, and avoid strong alkali and solvent cleaners.
How does it compare with aluminium? Aluminium does not rust but its oxide layer and coating age, and it transmits no light. Different jobs: daylight calls for PC, metallic appearance for aluminium.
Is yellowing a form of corrosion? No. It is photo-oxidation, a different mechanism with different consequences — affecting transmission and appearance, not structural integrity.
⭐⭐⭐⭐⭐ · August 12, 2026
Central Asia - Uzbekistan Focus (Customization & UV Resistance)
Impressive customization capabilities! We ordered the customized Double‑wall Narrow Grid sheets with Double Circular Edges for our recent urban project in Tashkent. The fit and finish are exceptional. Most importantly, the use of high‑quality 3R virgin raw materials provides the thermal stability and UV protection needed for the intense Uzbek sun. A top‑tier partner for Central Asian infrastructure.
⭐⭐⭐⭐⭐ · July 25, 2026
South America - Corrugated Selection (Volume & Patent)
The best selection of corrugated profiles in the market. Having access to 70+ free molds saved us significant tooling costs. We are extremely pleased with the Trapezoidal 1000 and the 1060 Wave/Trapezoidal sheets in Bronze and Yellow; there is zero color deviation across the entire batch. Furthermore, their Patented Reed Sheets have given our architectural projects a unique, high‑end texture that no other supplier can offer.
⭐⭐⭐⭐⭐ · June 18, 2026
Southeast Asia - Solid Sheet (Durability)
Our go‑to supplier for Solid Polycarbonate Sheets. In the humid and high‑heat environment of Southeast Asia, these solid panels maintain perfect transparency and high impact resistance. The quality of the resin is evident, and the service is always efficient。