IS 5326:2001 is the Indian Standard (BIS) for indian type water closets - specification (second revision). This standard specifies the requirements for materials, dimensions, manufacture, workmanship, finish, and testing of Indian type water closets made from vitreous china. It covers aspects like flushing efficiency and durability to ensure the quality and performance of these common sanitary fixtures.
Specifies material, dimensions, construction, and performance requirements for Indian type water closet (WC) pans.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
IS 5326 (2001) provides Indian Type Water Closets — Specification (Second Revision). Sets quality standards for squat-pan-type water closets still widely used in Indian homes, public toilets, institutional buildings, and rural facilities.
Use when: specifying Indian-type WCs for buildings; plumbing design for residential / institutional projects; sanitation facilities.
Indian-type (squat) WC characteristics: - Squat-pan design (vs European seated) - Material: vitreous china (preferred) or ceramic - Glazed surface for cleaning + durability - Flushing: cistern-fed; pressure: 0.5-3 m typical head
Sizes: - Standard: 300-450 mm depth - Floor opening: 200-250 mm dia - Pan dimensions per IS 5326
Material quality: - Vitreous china: zero water absorption; preferred - Ceramic: porous; lower cost; potential cleaning issues - Color: white most common; pastels available
Plumbing connection: - Inlet: 32 mm dia (with WC pan connector) - Outlet: 100 mm dia (trap + discharge) - Trap: P-trap or S-trap - Cistern: 6-9 litre capacity typical
Quality acceptance: - Visual: smooth surface, no chips / cracks - Dimensional tolerance per IS 5326 - Water tightness test - Flushing performance - Surface quality (no pinholes)
Standard WC pan: - Length: 300-450 mm - Width: 250-350 mm - Height (overall): 150-180 mm - Inlet position: rear or top - Outlet: bottom (typical S-trap or P-trap)
Cistern capacity: - 6 L (standard, water-efficient) - 9 L (older standard) - Modern: 4.5-6 L preferred (water conservation)
Installation: - Floor: ceramic / vitreous tiles + sloped to drain - Floor opening: per WC size - Trap: minimum 50 mm water seal - Vent pipe: connected to outlet (anti-siphon)
Plumbing standards: - Per IS 1742 (Building Drainage) - Per CPHEEO Manual on Building Plumbing - Per National Building Code - Trap + venting per IS 1742
Acceptance + service: - Service life: 25-50+ years - Cleaning: regular; surface durability key - Replacement: when chipped / broken - Maintenance: cistern + flushing mechanism
Modern alternatives: - European WCs (seated) — increasing popularity - Indian WCs still preferred in older buildings + rural - Dual mode (Indian + European in same toilet) - Smart toilets (research / premium market)
1. Sub-standard ceramic → chipping + cracking. 2. Trap depth inadequate → sewer gas in building. 3. No venting → siphon water trap; smells. 4. Wrong size for cistern → flushing inadequate. 5. Installation misaligned → leakage. 6. No anchorage to floor → WC moves. 7. Plumbing connections leak → mold + odor. 8. Cistern capacity too high → water wasted. 9. No water conservation → modern best practice.
1. Specification + procurement per IS 5326. 2. Installation per IS 1742 + manufacturer instructions. 3. Trap + venting verified. 4. Connection to plumbing. 5. Flushing test + acceptance. 6. Daily use + cleaning. 7. Maintenance (cistern mechanism + cleaning). 8. Service life 25-50 years; replace when damaged.
IS 5326 is the specification for Indian-style WCs — applied on every Indian building with traditional toilet design.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Water Absorption (Vitreous China) | Not more than 0.5% of its dry mass | Shall not exceed 0.5% | ASME A112.19.2-2018 |
| Minimum Trap Seal Depth | Not less than 50 mm | At least 50 mm | EN 997:2018 |
| Static Load Test | Withstand a load of 3.92 kN (400 kgf) without cracking | Withstand a vertical static load of 4.0 kN without cracking | EN 997:2018 |
| Trapway Passage Test (Ball Diameter) | Shall permit a solid ball of 50 mm diameter to pass freely | Shall pass a 2-1/8 in. (54 mm) diameter solid ball | ASME A112.19.2-2018 |
| Crazing Test (Autoclave Steam Pressure) | 0.35 ± 0.02 MPa for 1 hour | 70 ± 7 kPa (0.07 MPa) for 1 hour | ASME A112.19.2-2018 |
| Nominal Flush Volume | Designed for 10 L, 6 L, or 3/6 L cisterns | Max 1.6 gallons/flush (6 L) for standard; Max 1.28 gpf (4.8 L) for High-Efficiency Toilets | ASME A112.19.2-2018 / EPA WaterSense |
| Outlet Connection Size (Nominal) | 90±5 mm (Size 1) or 100±5 mm (Size 2) | Outlet spigot suitable for connection to 100 mm pipe | EN 997:2018 |