What are the common steel grades available for roofing sheets?

Grades are based on minimum yield strength, commonly Grade 240, Grade 340, and Grade 550 (in MPa), as per Table 3 of IS 15000 (Part 1).

What does the zinc coating class Z120 mean?

It signifies a minimum total coating mass of 120 grams per square meter over both surfaces of the sheet, as per Table 2 of IS 15000 (Part 1).

What is the T-bend test for pre-painted sheets?

It measures the flexibility and adhesion of the paint film upon bending. A lower value like '2T' indicates better performance. See IS 15000 (Part 2).

What is the typical thickness of roofing sheets?

Common nominal thicknesses (Base Metal Thickness) range from 0.40 mm to 0.80 mm. Tolerances are specified in Table 1 of IS 15000 (Part 1).

IS 15000

: 2000

Profiled sheets for roofing and wall cladding

CurrentFrequently UsedSpecificationBIMMaterials Science · Roofing Materials

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This standard specifies requirements for hot-dip zinc-coated (Part 1) and pre-painted (Part 2) steel sheets used for roofing and wall cladding. It covers base metal grades, coating mass, mechanical properties, dimensions, tolerances, and performance tests for durability.

Specifies requirements for profiled sheets made of various materials for roofing and wall cladding.

Quick Reference Values

Minimum yield strength for Grade 240240 MPa

Minimum yield strength for Grade 550550 MPa

Minimum zinc coating mass (Class Z120)120 g/m²

Minimum zinc coating mass (Class Z275)275 g/m²

Tolerance on thickness (0.40 to 0.50 mm)±0.04 mm

Tolerance on width (up to 1250 mm)+7 / -0 mm

Typical top coat paint thickness (pre-painted)15-20 microns

Practical Notes

The user-provided code/year combination is ambiguous. The information is based on the current active standard IS 15000:2019 (Part 1 & 2), which covers this topic.

Specify both grade (e.g., Grade 550) for strength and zinc coating class (e.g., Z120) for corrosion protection based on project requirements.

For pre-painted sheets, the paint system (RMP, SMP, PVDF) is critical for color fastness and durability and should be specified as per environmental conditions.