What are the common alloys specified for roofing sheets in this standard?

Commonly used alloys include 31000, 31050, and 52000. Their properties are given in Tables 1 and 2.

What does the 'H' temper designation mean?

The 'H' temper indicates that the material is strain-hardened to increase its strength. The digits following 'H' specify the degree of hardening (e.g., H14 is half-hard).

What is the minimum tensile strength for Alloy 31050 in H14 temper?

145 MPa (or N/mm²), as per Table 2.

Does this IS code specify the profile or shape of the roofing sheet?

No, it only specifies the properties of the flat sheets, strips, and plates that are used to manufacture the final profiled products.

IS 14756

: 2000

Aluminium and aluminium alloy sheets, strips, and plates for roofing and cladding

CurrentFrequently UsedSpecificationBIMArchitectural · Roofing Materials

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This standard specifies the requirements for aluminium and aluminium alloy sheets, strips, and plates used for roofing and cladding. It details the chemical composition, temper conditions, mechanical properties (such as tensile strength and elongation), and dimensional tolerances for various alloys.

Specifies requirements for aluminium and aluminium alloy sheets, strips, and plates intended for roofing and cladding.

Quick Reference Values

Minimum tensile strength for Alloy 31000 (H2 Temper)140 MPa

Minimum tensile strength for Alloy 31050 (H14 Temper)145 MPa

Minimum elongation for Alloy 31000 (O Temper) on 50 mm gauge length20 %

Standard thickness tolerance for 1mm thick sheet (up to 1250mm wide)±0.10 mm

Copper content limit for Alloy 310500.30 % max

Magnesium content limit for Alloy 520002.2-2.8 %

Practical Notes

This standard covers the base metal only; coatings or paints applied to the sheets are covered by other standards like IS 13871.

The choice of alloy and temper (e.g., 31050-H14) is critical, balancing strength requirements with the formability needed for specific roofing profiles.

The standard does not provide design guidance for wind loads on roofing/cladding systems; this must be addressed separately using codes like IS 875 (Part 3).