---
title: TfNSW R0220 Stormwater Pit Pattern
type: concept-note
status: live
created: 2026-05-04
created_by: cowork-lfcs (Phase 7)
applies_to_job_types:
  - stormwater-pit
  - drainage-pit
  - kerb-inlet-pit
related_specs:
  - "[[TfNSW R11 Stormwater Drainage]]"
  - "[[TfNSW R53 Concrete for General Works]]"
related_concepts:
  - "[[Defensible-for-variations-posture]]"
  - "[[Common-pricing-misses]]"
canonical_examples:
  - "[[2626 - Mack Civil - Stormwater Pit EXA01A-08]]"
---

# TfNSW R0220 Stormwater Pit Pattern

> **When to apply:** any LFCS bid for a TfNSW dayworks pit job (or pit-shaped scope) where the head contractor is a civil contractor (Mack Civil, RoadTek, etc.) supplying materials and LFCS provides FRP install only. Read this BEFORE pricing. Wikilink in per-job CLAUDE.md Patterns section.

## TL;DR — what this pattern locks down

1. **LFCS scope = FRP-INSTALL-ONLY** (pure form + reinforce + pour install labour). Demolition, excavation, ALL major supplies, backfill, and ancillaries default to head-contractor scope.
2. **Concrete grade defaults to N25** per TfNSW R0220 standard (Note 1 on R0220-style drawings).
3. **Step irons mandatory if pit depth > 600mm** (R0220 Note 2 — galv AS 1657 + AS/NZS 4680).
4. **R20 rounded edges on ALL exposed concrete** (R0220 Note 3).
5. **50mm minimum cover to reinforcement** unless drawing shows otherwise (R0220 Note 4).
6. **Pit depth max 3500mm** (R0220 Note 8). Beyond = different design + different rate.
7. **100mm minimum gap between pit walls and pipe penetrations** (R0220 Note 9). Affects formwork detail.
8. **R11 + R53 spec compliance is the heavy lift** — Project Quality Plan, Hold Points, Witness Points, NATA-endorsed mix, ACRS-certified reo, AAR-tested aggregates, Cert of Conformity per pour. Allow ~1.5 supervisor-days of admin per pit.

## Default supply boundary (FRP-install-only)

LFCS supplies (typical):
- Formwork ply + edge boards + bracing/fixings
- Bituthene seal (joints + lifting holes per R11 4.5.3 + 4.4.4)
- Curing compound (per R53 3.4 — AS 3799 Class B Type 1-D)
- Grout / seal at penetrations
- Small tools + ute&tools

Head contractor supplies (Mack Civil / RoadTek / etc., typical):
- N25 ready-mix concrete (must be on TfNSW Register of Concrete Mixes per R53 2.4.3 — OR project-assessed mix with 5+ working days lead time HOLD POINT)
- N12 reinforcement (Grade 500N, ACRS-certified per R53 1.4)
- Precast SAS lintel (TfNSW R0220-03)
- SA grate frame (TfNSW R0220-04, Class D galv steel or ductile iron)
- Galvanised step irons (AS 1657 + AS/NZS 4680)
- Sand bedding (under pit base)
- Backfill (Type SO Select Fill side+overlay zones per R11 4.9, general fill)
- Demolition + disposal of existing pit
- Non-destructive excavation around live pipes
- Traffic management / road closure / sediment control / lighting / survey
- ERSED + dewatering
- Concrete pump
- CCTV inspection per R11 5.2

**Sensitivity per supply item LFCS picks up** (typical $ swing for a small pit, scale with size):
- Concrete supply: +$1,000-$1,500
- Reo supply: minor
- SAS lintel supply: +$1,200
- SA grate frame supply: +$1,000
- Step irons supply: +$200
- Sand bedding supply+place: +$150
- Backfill supply+place: +$200-$500
- ERSED materials: +$250
- Non-destructive excavation: +$1,500-$2,500 (specialist labour + plant)

## Risk tags (always carry on bid submission)

| Risk | Severity | Mitigation in submission |
|---|---|---|
| Live pipe through pit footprint (DN450+ RCP penetration common) | HIGH | Pipe-strike repair excluded unless caused by direct LFCS strike; pre-mark pipe location with Site Supervisor before excavating |
| AfC drawings not in pack at bid time | HIGH | Pricing assumes pit dimensions per TfNSW R0220 standard; any deviation in AfC drawings = variation |
| RFI contractor acceptance unsigned at bid time | HIGH | Pre-condition to LFCS commencement: head contractor signs RFI acceptance before mob |
| Inadequate foundation material | MEDIUM | R11 4.3.3 Hold Point — variation at dayworks rates if encountered |
| NATA mix not on TfNSW Register | MEDIUM | +5 working days programme + $300 admin (per R53 2.4.3 Hold Point) |
| Concrete temperature limits (R53 3.3.2 — air <5°C or >35°C, concrete <10°C or >32°C) | LOW | Identified Record per R53 3.3.2; price weather-related cancellation as variation |
| Adverse weather cancellation | MEDIUM | Variation at dayworks rates per Rate Card V1.7 Min Call-Out clause |
| CCTV inspection (R11 5.2) — usually not LFCS scope | LOW | Confirm with head contractor; if LFCS = specialist subby cost |

## Key TfNSW Standard Drawings (always reference)

- **R0220-01** — cast-in-situ pit base (default geometry)
- **R0220-03** — precast SAS lintel
- **R0220-04** — grate frame SA
- **R0220-05** — frame + grate detail (cross-ref from R0220-04)
- **R0220-28** — deep pit / pipe diameter >450mm (referenced by R0220 Note 6)
- **R0220-43** — pit-to-pipe connection (rocker pipe)

## Spec compliance checklist (R11 + R53)

**R11 Stormwater Drainage Hold Points (typical):**
- 4.3.3 — inadequate foundation material treatment
- 4.4.2 — Cert of Conformity for joints pre-backfill (Engineer-signed, ~$500 external)
- 5.2 — CCTV inspection before pavement reinstatement (often head-contractor scope)
- 4.7.2 — construction of "other drainage structures" notification (24h-7d advance to Principal)

**R11 Witness Points (typical):**
- 4.3 — excavation for drainage structures (24h-7d advance notice)
- 4.7.2 — construction
- 4.4.4 — sealing of lifting holes + flush/butt joints (small but easy to forget)

**R53 Concrete Hold Points (typical):**
- 2.4.3 — NATA mix project assessment (5+ working days lead time if not on TfNSW Register)
- 3.3.2 — concrete temperature limits (Identified Record)
- 3.3.9 — construction joint roughened+clean prep

## Pricing pattern — refer to pricing-checklist.md

1. **Phase 0 — Pre-Pricing-Grill MANDATORY** before any rate set. Lock supply boundaries via Q-A through Q-G with head contractor / Rocky.
2. **Phase 5 mandatory output structure:** 6-sheet Tender Summary (Cover + Option A Lump Sum + Option B Schedule of Rates + Exclusions [Block A RFQ-mirror + Block B defensive] + Terms + Dimensions & Assumptions) + 5-sheet Rate Buildup (Labour + Materials + Summary + Sensitivity + Sources & Notes). **Calc Basis column on every Tender Summary line.**
3. **Defensible-for-variations posture** ([[Defensible-for-variations-posture]]) — Rate Card V1.7 hourly basis (day shift $85/$95 supervisor; night shift $140/$150 supervisor).
4. **Midnight crossing loading $9,080 single-line item** for night work (per Rate Card V1.7 — every shift 19:00-05:00 crosses midnight = extra 8 hrs at day shift rate per person per shift). [[Common-pricing-misses]] entry — never skip this check on night jobs.
5. **15% redundancy** on subtotal (Rocky's standard "redundancy / margin" applied to Labour + Materials + External).

## Canonical example — 2626 Mack Civil Stormwater Pit EXA01A/08

See [[2626 - Mack Civil - Stormwater Pit EXA01A-08/CLAUDE]] for the full per-job context.

Pricing iteration story: 5 revisions (v1 → rev5) over a single day before settling on FRP-install-only scope at $43,143 ex GST. Lessons from this iteration codified into:
- `lfcs-standards/pricing-checklist.md` Common Misses log
- This concept note (FRP-install-only default + supply boundary table)
- `lfcs-airtable-sync` adapter skill (prevents the dup pattern hit during rev cycle)

If you're pricing a similar pit job, **start from this concept note + the 2626 reference, not from a blank slate.** The lessons are baked in.

## Quick query — "all pit-shaped jobs in Airtable"

Filter `Jobs` table by Notes contains "pit" OR Name contains "Pit" — until we add a `Job Type` field (Phase 8 candidate).