IS 1130:1969 is the Indian Standard (BIS) for kota stone (limestone) - specification. This standard lays down the specifications for Kota stone (a hard, compact limestone) used for flooring, facing, and paving. It defines acceptable dimensions, physical properties, and tolerances to ensure structural and architectural quality during construction.
Specifies requirements for Kota stone (limestone) used as building material, including physical characteristics and quality.
Acceptance and finish/laying key points.
| Reference | Value | Clause |
|---|---|---|
| Stone type | Hard, fine-grained limestone | Material |
| Durability screen | Low water absorption (IS 1124) | IS 1124 |
| Strength | Adequate for traffic (IS 1121) | IS 1121 |
| Non-slip finish | Machine-rubbed / honed (circulation, wet, ramps) | Finish |
| Polished finish | Slippery when wet — controlled areas only | Finish |
| Tolerance | Thickness & squareness within IS 1130 | Acceptance |
| Laying | Full mortar contact, no hollow tiles (IS 1443) | IS 1443 |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
IS 1130:1969 is the specification for Kota stone (limestone) — the hard, fine-grained limestone (the familiar greenish/blue-grey 'Kota' flooring) widely used for flooring, paving, treads, skirting, and external hard-wearing surfaces in Indian construction. It defines the quality, dimensions, dressing and acceptance of Kota stone slabs and tiles.
It is read with the stone-test and finishes stack:
IS 1130 sets the quality and acceptance parameters for Kota limestone:
Kota is valued for being hard-wearing, naturally non-slip (in rough/honed finish), and economical — which is exactly why it is specified for high-traffic floors, staircases, corridors and external paving.
Scenario: a Kota stone lot for a high-traffic corridor floor, 25 mm slabs.
Step 1 — sampling & visual: representative slabs checked for cracks, veins, cavities, colour uniformity and dressing quality; reject veined/decayed pieces.
Step 2 — dimensions: thickness and squareness within IS 1130 tolerance — out-of-tolerance slabs give lipping and uneven joints in the laid floor.
Step 3 — water absorption (IS 1124): low absorption confirms the dense, durable limestone — high absorption flags a soft, staining-prone or weathered stone; reject.
Step 4 — strength (IS 1121): adequate for the traffic class.
Step 5 — finish & laying: specify the finish (machine-rubbed for non-slip corridors; mirror-polished only where slip risk is managed); lay on the IS 1443 bedding mortar with full contact (no hollow tiles).
Accept only slabs sound on all four — visual, dimension, absorption and strength; the polished sample tile is not the acceptance basis for the bulk.
1. Accepting on a polished showroom tile. Natural stone varies block-to-block; test and visually grade the delivered lot, not the sample.
2. Ignoring water absorption. A soft, weathered or high-absorption 'Kota' stains, wears and disintegrates — IS 1124 absorption is the cheapest durability filter and is routinely skipped.
3. Mirror-polish in wet/high-slip areas. Polished Kota is slippery when wet — specify machine-rubbed/honed for ramps, bathrooms, external and circulation areas (an NBC Part 6 slip-safety issue).
4. Thickness/squareness out of tolerance. Causes lipping, hollow tiles and joint mismatch — check dimensions, not just appearance.
5. Poor bedding (hollow tiles). Laid without full mortar contact, Kota cracks under traffic regardless of stone quality — laying workmanship per IS 1443 is half the result.
IS 1130:1969 is old and reaffirmed; Kota stone remains a default for economical, durable, high-traffic Indian flooring — corridors, staircases, parking, terraces and back-of-house areas — because it wears extremely well and, in a honed/rubbed finish, is naturally slip-resistant. The competition is vitrified tiles and engineered stone, but Kota still wins on cost-per-year of service for heavy-traffic utilitarian floors.
The two practitioner disciplines that prevent almost all Kota complaints: (1) buy and test by lot — visual grading plus IS 1124 absorption to weed out soft/weathered material; and (2) match finish to slip risk — never mirror-polish wet/circulation areas. Get the bedding right (full contact, no hollow tiles, IS 1443) and a correctly-specified Kota floor outlasts most alternatives.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Compressive Strength (min) | ≥ 108 N/mm² (MPa) | ≥ 55 MPa | ASTM C568 (for High-Density Limestone) |
| Water Absorption (max, by weight) | ≤ 1.0% | ≤ 3.0% | ASTM C568 (for High-Density Limestone) |
| Transverse Strength / Modulus of Rupture (min) | ≥ 13.7 N/mm² (MPa) | ≥ 6.9 MPa | ASTM C568 (for High-Density Limestone) |
| Specific Gravity / Density (min) | Specific Gravity ≥ 2.6 | Density ≥ 2560 kg/m³ (SG ≈ 2.56) | ASTM C568 (for High-Density Limestone) |
| Abrasion Resistance | Not Specified | Required for flooring/paving (e.g., Class 3 paving requires ≤ 20 mm loss in Wide Wheel Abrasion Test) | EN 1341 |