Shallow corrugated asbestos cement sheets
1990 Edition

The IS 13008:1990 standard specifies the essential requirements for shallow corrugated asbestos cement sheets used mainly in roofing and cladding. According to Clause 5.1 and Table 1, the sheets must meet defined dimensional parameters with specified tolerances (all measurements in millimeters). Key dimensions include corrugation depth (20 ± 2 mm), pitch of corrugation (75 ± 15 mm), overall width (1015 +10/-5 mm), nominal thickness (4.2 mm with +free/-0.2 tolerance), and sheet length (2000 or 2250 ±10 mm). Figures illustrate sheet profiles and measurement tools, and rounding of results should follow IS 2:1960 rules. These criteria ensure consistent manufacturing and quality control.

IS 13008 cross-references multiple Indian Standards crucial for compliance, as listed in Annex A. It aligns with international standard ISO 393/1-1983 concerning asbestos cement corrugated sheets and fittings. Testing results must be rounded according to IS 2:1960 to maintain uniform significant figures. Notable referenced codes include IS 2 (rounding rules), IS 1599 (sampling and analysis methods), IS 3461 (corrugated sheet specifications), and IS 2546 (testing methods for asbestos cement products). Users are advised to consult these standards for comprehensive compliance.

According to Clause 4.1, the sheets can be produced in either natural color or pigmented forms, with pigments required to be permanent and conforming to IS 5913:1989 standards for colorfastness and staining resistance. The sheets are composed of clean asbestos fibers combined with suitable additional fibers and cement binders such as 33 grade Ordinary Portland Cement (IS 269:1989), Portland Slag Cement (IS 455:1989), or Portland Pozzolana Cement (IS 1489:1976), with the latter not permitting additional pozzolanic additives. Dimensions and tolerances (Clause 5.1, Table 1) include corrugation depth (20 ± 2 mm), pitch (75 ± 15 mm), width (1015 +10/-5 mm), thickness (4.2 mm with +free/-0.2 tolerance), and length (2000 or 2250 ±10 mm). Pitch measurement is taken over six corrugations to ensure accuracy.

IS 13008 mandates that pigments incorporated into asbestos cement sheets must be permanent in color and comply with applicable Indian Standards, specifically IS 5913:1989, which governs pigment color and staining power. Pigments must be compatible with asbestos cement to avoid compromising durability. The cement matrix consists of asbestos fibers, additional fibers, and binders such as OPC, PSC, or PPC, with strict limitations on pozzolanic material usage when PPC is employed. Dimensional tolerances for the sheets are consistent with those outlined in Table 1, Clause 5.1.

The standard defines precise dimensions and tolerances for shallow corrugated sheets (Clause 5.1, Table 1). Corrugation depth is set at 20 mm with a ±2 mm tolerance, pitch at 75 mm with ±15 mm, overall width at 1015 mm with +10/-5 mm variation, nominal thickness at 4.2 mm allowing for a reduction of 0.2 mm but no increase, and length options of 2000 or 2250 mm with ±10 mm tolerance. Pitch is measured cumulatively over six corrugations to ensure conformity. These tolerances maintain the structural fit and aesthetic uniformity of the sheets.

The sheets must exhibit compliance with specified physical and mechanical properties including dimensional accuracy as per Table 1 (Clause 5.1). Corrugation depth and pitch tolerances are maintained at ±2 mm and ±1.5 mm, respectively; overall width and length must adhere to their respective tolerances; thickness is measured with an anvil to ensure it does not exceed the nominal value but may be slightly thinner. Proper marking as per Clause 11.2 is required to certify conformity. These measures ensure the sheets meet performance and safety standards.

Sheets should be rectangular with a smooth weather-resistant surface free from visible defects. Corrugations are expected to be regular and true, and edges must be straight and clean (Clause 7.1). Colour options include natural or pigmented finishes with pigments required to be permanent following IS 5913:1989 standards. Dimensional tolerances for depth, pitch, width, thickness, and length must be met to ensure uniformity and quality.

Sampling and inspection processes should follow IS 7639:1975 guidelines, with lot sizes mutually agreed upon by manufacturer and purchaser. Inspection includes dimensional checks against prescribed tolerances and quality assessments. Manufacturers are obliged to provide a compliance certificate upon request (Clause 9.2). Rounding of numerical test results must follow IS 2:1960. This ensures systematic quality control and acceptance criteria.

Inspection procedures adhere to IS 7639:1975 with agreed lot sizes between parties. Dimensional conformity is verified against Table 1 tolerances (Clause 5.1). The manufacturer must issue a certificate confirming adherence to IS 13008 upon purchaser’s request (Clause 9.2), ensuring traceability and quality assurance. Sheets may bear the Standard Mark as per Clause 11.2. Thickness is measured using the anvil method detailed in Fig. 2.

Manufacturers are responsible for providing personnel and necessary equipment at their own cost for testing conducted on-site (Clause 10.1). Test results are to be rounded in accordance with IS 2:1960. The certificate of compliance must be issued upon request (Clause 9.2). Measurements include dimensional checks as per Table 1, with thickness assessed through the anvil method. This ensures transparency and conformity to IS 13008 specifications.

Each corrugated sheet must be clearly and permanently marked with the manufacturer’s name or trademark, manufacturing year and date, and a pictorial warning as prescribed by IS 12081 (Part 2) 1987 (Clauses 11.1 and 11.2). Optionally, the Standard Mark indicating certification may be applied. Thickness measurement follows the anvil method (Fig. 2). These markings facilitate product traceability, safety warnings, and standard compliance.

Manufacturers are required to provide safety instruction sheets with all deliveries of shallow corrugated asbestos cement sheets (Clause 12.1). These safety guidelines must conform to IS 11769 (Part 1): 1987, detailing safe handling, dust control, use of personal protective equipment such as masks and gloves, secure transportation, and appropriate labeling with warning signs as per IS 12081 (Part 2): 1987. Strict adherence to these rules is critical to prevent health hazards related to asbestos exposure.

IS 13008 references several Indian Standards pertinent to asbestos cement products and cement types, including IS 269 (Ordinary Portland Cement), IS 455 (Portland Slag Cement), IS 1489 (Portland-Pozzolana Cement), IS 5913 (Test Methods for Asbestos Cement Products), IS 7639 (Sampling Procedures), IS 11769 (Safety Guidelines), and IS 12081 (Warning Signs). These standards provide a comprehensive framework for material specifications, testing, sampling, safety measures, and product identification.

The Technical Committee responsible for IS 13008 comprises experts from academia, government agencies, research institutions, and industry, including representatives from Orissa Cement Ltd, CPWD, Hyderabad Industries Ltd, CSIR Structural Engineering Research Centre, Larsen & Toubro, and others. The committee is chaired by Dr. H. C. Visvesvaraya of the University of Roorkee with the Central Board of Irrigation and Power serving as Member-Secretary. This diverse composition ensures the standard's development is comprehensive and authoritative.