| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. PIPE QUALITY & PLACEMENT | |||
| A1 | Drainage pipes are undamaged; no cracks, chips, or deformation visible Acceptance: Pipes inspected, no visible defects, test certificate checked | Cl. 3.1 — Physical condition | |
| A2 | Pipes laid on sand cushion with proper support; no direct contact with trench bottom Acceptance: Sand cushion 100mm, pipe seats on sand, even bearing along length | Cl. 4.1 — Support | |
| A3 | Pipe alignment checked - alignment straight along the line per design Acceptance: Alignment verified with string line, no lateral deviation >25mm per 100m | Cl. 4.2 — Alignment | |
| B. JOINTING & CONNECTIONS | |||
| B1 | Spigot fully inserted into socket with minimum 1/3 pipe diameter overlap (typically 100-150mm) Acceptance: Spigot inserted minimum 100mm, socket rim visible around spigot, tight fit | Cl. 5.1 — Joint depth | |
| B2 | Mortar joint applied (1:2 cement:sand) at socket interface; filled completely around circumference Acceptance: Mortar filled 100% around joint, cured 48 hours before backfill, joint strength verified | Cl. 5.2 — Mortar joint | |
| B3 | Joint is tested for water flow (if required for gravity lines) - no seepage observed Acceptance: Visual inspection shows no water seeping from joint interface | Cl. 5.3 — Leakage test | |
| C. GRADIENT & INVERT LEVEL | |||
| C1 | Gradient (slope) verified as per design (typical 0.3-2.0% for gravity drainage) Acceptance: Measured slope within design ±5%, documented at inlets/outlets/midpoints | Cl. 6.1 — Gradient | |
| C2 | Invert levels at each pipe junction checked for proper drop/transition Acceptance: Invert level allows gravity flow, drops at junctions reasonable (>50mm preferred) | Cl. 6.2 — Invert level | |