Galvalume Roofing Sheets
We offer galvalume roofing sheets which are tailor made as per the requirement of the clients andthey all have a standard width of 1 Meter.
What is Galvalume?
It is a flat rolled steel sheet coated with alloy of Aluminium & Zinc, produced by a continuous hot dip process. It is a result of over 20 years of research. Galvalume has an attractive appearance and has been well accepted as a preferred alternative over both Galvanized Steel sheets and aluminium coated steel sheets in areas such as Roofing, Cladding, Gutters and Accessories.
Composition of Galvalume Sheet:
Specifications
| Material | Minimum Tensile Strength | Coating | |
|---|---|---|---|
| 55% Aluminium | Alloy coated High Tensile Steel | 550 N/mm2 (GRADE 550) | Coating Mass of AZ150 (150 g/m2 both sides) |
| 43.5% Zinc | |||
| 1.5% Silicon | |||
Standards
| America: | ASTM A 792 |
| Japan: | JIS G 3321:1998 |
| Australia: | AS1397 |
| Singapore: | SS 370:1994 .ISO :9364 |
CORROSION RESISTANCE
Salt Spray Test
Salt Spray test is one of the methods used to demonstrate the high corrosion resistance of Galvalume steel.The improved corrosion resistance of 55% AL-Zn alloy coated steel coil is derived from the unique combination of the barrier protection of the aluminium and the sacrificial protection of the zinc. The formation of an insouble aluminum oxide layer provides the barrier protection while the zinc provides a sacrifical protection at cut edges, scratches and areas of coating damage.
| Material | Coating Wt | Number of hours before visible red rust | |
|---|---|---|---|
| Galvalume | 150g/m2 | 40 µ (Both Sides) | 5,500 Hr |
| Galvanized | 275g/m2 | 40 µ (Both Sides) | 300 Hr |
EXPOSURE TEST - CUT EDGE PROTECTION
Exposure testing of 55% Al - Zn alloy coated steel coils has been conducted for over 20 years in various atmospheric environments. The testing also demonstrated a superior cut edge production of 55% Al - Zn alloy coated steel sheet than galvanized steel sheet.
Galvanized steel sheet
4% Al-Zn Alloy-coated steel sheet
7% Al-Zn Alloy-coated steel sheet
55% Al-Zn Alloy coated steel sheet
Edge Appearance of coated sheet after about 17 Years Industrial Exposure (Bethlehem.PA.U.S.A)
| Material | Coating Wt | HeatTransmission:h/watt/m2 |
|---|---|---|
| Galvalume | 150g/m2 | 5,500 Hr |
| Galvanized | 275g/m2 | 300 Hr |
| Terra cotta | Tile Roof | 150 |