What is the primary application of IS 12866 sheets?

They are mainly used as translucent roofing or side-cladding panels (skylights) in structures like warehouses, factories, and greenhouses to provide natural daylight.

What is the difference between Type 1 and Type 2 sheets?

Type 1 is for general purpose applications, while Type 2 is fire-retardant, offering better performance in case of fire.

What is the minimum required light transmission for these sheets?

Minimum light transmission is 65% for Type 1 (general purpose) and 60% for Type 2 (fire-retardant) sheets, as per Table 2.

What is the specified minimum glass content?

The minimum glass content by mass for all types of sheets is 25% (Clause 6.2).

IS 12866

: 1989

plastic translucent sheets made from thermosetting polyester resin (glass fibre reinforced)

CurrentSpecializedSpecificationBIMMaterials Science · Flooring, Wall Finishing and Roofing

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This standard specifies the requirements and testing methods for translucent plastic sheets made from glass-fibre reinforced thermosetting polyester resin. It covers material composition, dimensions, physical properties like light transmission, and mechanical properties like tensile and flexural strength for sheets used in roofing and cladding.

plastic translucent sheets made from thermosetting polyester resin (glass fibre reinforced)

Quick Reference Values

Minimum Glass Content (by mass)25 %

Minimum Light Transmission (Type 1)65 %

Minimum Light Transmission (Type 2)60 %

Maximum Water Absorption0.5 %

Minimum Tensile Strength70 MPa

Minimum Flexural Strength100 MPa

Barcol Hardness (Minimum)35

Practical Notes

These sheets are commonly used for skylights in industrial and agricultural buildings to allow natural light, reducing electricity costs.

Ensure the profile of the GRP sheet matches the profile of the main metal roofing sheets for proper fit and sealing against water ingress.

The standard specifies Type 1 (general purpose) and Type 2 (fire-retardant) sheets; selection should be based on the building's fire safety requirements.