| # | Code | Description | Unit | Qty | Rate (₹) | Amount (₹) |
|---|---|---|---|---|---|---|
| 1 | 2.8.1 | ExcavationEarth work in excavation by mechanical means (Hydraulic excavator) / manual means in foundation trenches or drains (not exceeding 1.5 m in width or 10 sqm on plan), including dressing of sides and ramming of bottoms, for all lift, including getting out the excavated soil and disposal of surplus excavated soil as directed, within a lead of 50 m. — All kinds of soil. | Cum | 4.52 | 260.30 | 1,176.56 |
| 2 | 4.1.10 | Pcc BedProviding and laying in position cement concrete of specified grade excluding the cost of centering and shuttering - All work up to plinth level : — 1:5:10 (1 cement : 5 coarse sand (zone-III) derived from natural sources : 10 graded stone aggregate 40 mm nominal size derived from natural sources) | Cum | 0.18 | 6,518.60 | 1,173.35 |
| 3 | 6.4.2 | Brick WallsBrick work with common burnt clay F.P.S. (non modular) bricks of class designation 7.5 in superstructure above plinth level up to floor V level in all shapes and sizes in : — Cement mortar 1:6 (1 cement : 6 coarse sand) | Cum | 1.56 | 9,105.95 | 14,205.28 |
| 4 | 4.10 | DpcProviding and laying damp-proof course 40 mm thick with cement concrete 1:2:4 (1 cement : 2 coarse sand (zone-III) derived from natural sources : 4 graded stone aggregate 12.5 mm nominal size derived from natural sources) | Sqm | 0.69 | 410.85 | 283.49 |
| 5 | 5.3 | Rcc Cover SlabReinforced cement concrete work in beams, suspended floors, roofs having slope up to 15° landings, balconies, shelves, chajjas, lintels, bands, plain window sills, staircases and spiral stair cases above plinth level up to floor five level, excluding the cost of centering, shuttering, finishing and reinforcement with 1:1.5:3 (1 cement : 1.5 coarse sand(zone-III) derived from natural sources : 3 graded stone aggregate 20 mm nominal size derived from natural sources). | Cum | 0.14 | 11,505.50 | 1,610.77 |
| 6 | 5.9.3 | Centering SlabCentering and shuttering including strutting, propping etc. and removal of form for — Suspended floors, roofs, landings, balconies and access platform | Sqm | 1.44 | 927.25 | 1,335.24 |
| 7 | 5.22.6 | SteelSteel reinforcement for R.C.C. work including straightening, cutting, bending, placing in position and binding all complete upto plinth level. — Thermo-Mechanically Treated bars of grade Fe-500D or more. | Kg | 14.42 | 107.85 | 1,555.20 |
| 8 | 13.1.2 | Plaster Int12 mm cement plaster of mix : — 1:6 (1 cement: 6 fine sand) | Sqm | 5.94 | 333.35 | 1,980.10 |
| 9 | 4.1.10 | Benching PccProviding and laying in position cement concrete of specified grade excluding the cost of centering and shuttering - All work up to plinth level : — 1:5:10 (1 cement : 5 coarse sand (zone-III) derived from natural sources : 10 graded stone aggregate 40 mm nominal size derived from natural sources) | Cum | 0.08 | 6,518.60 | 521.49 |
| 10 | 7132 | Manhole CoverCircular shape 450 mm dia precast R.C.C. manhole cover with frame - L.D. - 2.5 | Each | 1.00 | 610.00 | 610.00 |
| 11 | 5.22.6 | Step IronsSteel reinforcement for R.C.C. work including straightening, cutting, bending, placing in position and binding all complete upto plinth level. — Thermo-Mechanically Treated bars of grade Fe-500D or more. | Kg | 4.80 | 107.85 | 517.68 |
| Your inputsChamber shape Rectangular · Inside dimension 900 mm · Inside width 600 mm · depth 1.5 m · Wall thk 230 mm · MS step irons · -concrete benching at invert · chambers 1 | TOTAL | ₹24,969 | ||||
- **Sizing rule** (IS 4111 + CPHEEO Manual on Sewerage): inside dimension ≥ 900 mm for any chamber ≥ 1.0 m deep (must allow safe person entry). Smaller 600/750 mm chambers acceptable only for shallow utility-access chambers (≤ 0.9 m deep) with rod-cleaning access from above.
- **Rectangular vs circular**: rectangular is simpler to build + cheaper for shallow chambers (< 1.5 m). Circular is structurally efficient for deep chambers (≥ 2.0 m) — hoop tension distributes wall load uniformly, allowing thinner walls. Switch via dropdown.
- **Wall thickness ladder** (IS 4111 Table 1): ≤ 2 m deep → 230 mm; 2-4 m → 345 mm (1½-brick); > 4 m → 460 mm (2-brick) or switch to RCC. For very deep manholes (> 6 m) RCC ring chambers are standard — different template.
- **Step irons** (MS 20 mm dia bent to L-shape, embedded into wall during construction) are mandatory for any manhole ≥ 1.0 m deep per IS 4111. Spacing: 300 mm vertical, first step 300 mm below cover. Steel quantity formula approximates 1.2 kg per step.
- **Benching** (cement concrete sloped surface at the invert level guiding flow toward the outlet) is essential for sewer manholes — prevents stagnation + cleaning. Skip for water-supply manholes (no continuous flow at invert).
- **RCC cover slab thickness** auto-scales: ≤ 0.9 m chamber → 100 mm; 0.9-1.2 m → 125 mm; > 1.2 m → 150 mm slab with 12 mm bars. For under H-class traffic load (highway carriageway), bump to next thickness manually.
- Excludes: drop manhole arrangement for deep sewer drops > 600 mm (use CPHEEO Manual on Sewerage Section 5.7 design); cast-iron rim flush with paved carriageway (₹4,000-6,000 extra); approach paving; under-bench channel formation for multi-pipe manholes; safety chain / hook for confined-space rescue.
- **Cost target** for the standard 900 × 600 × 1.5 m rectangular manhole with 230 mm brick walls + 125 mm RCC cover + CI cover + 4 step irons + benching: approximately ₹18,000-22,000 per chamber per CPWD DSR 2023 (excluding GST + contractor profit).
A **Manhole / Inspection Chamber** is the brick or RCC pit that provides maintenance access to buried pipelines — the single most-quoted civil item in any infrastructure BOQ. Every gravity sewer has one every 30 m; every storm drain has one at every direction change; every water-supply network has them at junctions, off-takes, and flushing points. Per **IS 4111 Part 1** the standard chamber is rectangular brick masonry (900 × 600 mm inside ≥ 1.0 m deep), with PCC bed, RCC cover slab, CI manhole frame + cover, step irons, and (for sewers) cement-concrete benching at the invert. This Builder generates the per-chamber BOQ for any size + depth + shape, and you set the chamber count for your whole project — a typical JJM village scheme has 40-80 chambers totaling ₹8-16 lakhs.
When to use a manhole vs an inspection chamber vs a junction box
**Manhole** — large chamber (≥ 900 mm inside, ≥ 1.0 m deep) sized for safe person entry with step irons + benching + manhole cover. Mandatory on gravity sewers per CPHEEO Manual + on any drainage line ≥ 600 mm dia. **Inspection Chamber** — smaller chamber (450-750 mm inside, ≤ 0.9 m deep) for rod-cleaning access only (no person entry). Used on house drainage connections + small storm drains + cable / telecom drop chambers. Same construction, smaller size, no step irons needed. **Junction Box** — purely structural chamber at the meeting point of 2+ pipes; sized to fit pipe geometry + provide hand access for jointing. Often a custom-shaped variant of the inspection chamber. **For water-supply mains** all three are loosely called 'valve chambers' depending on what's inside — see [SVC](/boq/sluice-valve-chamber) and [AVC](/boq/air-valve-chamber) templates for purpose-built water-valve enclosures.
Construction sequence
(1) Set out chamber centre + orientation w.r.t. incoming + outgoing pipes. (2) Excavate trench to design depth + 300 mm working room all round. (3) Lay 100 mm PCC bed M10. (4) Build brick walls in CM 1:6, starting from 230 mm thick at bottom (or 345 mm if deeper than 2 m); raise course-by-course. (5) Embed step irons at 300 mm vertical c/c as walls rise (first step 300 mm below cover level). (6) Apply DPC bitumen layer at plinth. (7) For sewer chambers — build benching at invert level (1:6 cement concrete sloped 1:10 toward outlet). (8) Cast 125 mm RCC cover slab with central opening for manhole cover (typically 600 × 450 mm clear opening, frame embedded in slab). (9) Internal cement plaster CM 1:3 finishing smooth. (10) Backfill in 200 mm lifts, watered + tamped. (11) Install CI manhole cover + frame, set flush with finished surface.