Repair Systems — 04
Step and counter-flashing systems — lead sheet
Technical product reference for lead sheet step and counter-flashing on pitched tiled roofs. Covers the lead code system (Code 3, 4, 5), forming and dressing, fixings, health and safety handling requirements, and brand comparisons — Austral Lead and Calder Industrial — for Australian heritage and high-specification remediation.
What are lead sheet step and counter-flashings?
Lead sheet step and counter-flashings are the traditional roofing flashing material for pitched tiled roofs, used in Australia from early colonial construction through to the mid-twentieth century when Colorbond and aluminium alternatives became dominant. Lead is valued for its malleability — it can be hand-dressed by an experienced roof plumber into complex three-dimensional profiles around chimneys, irregular masonry walls, and other abutments without requiring a sheet metal folder or power tools. Critically, lead is self-sealing at overlaps — it compresses and conforms under the weight of overlying tiles and materials, creating a naturally weathertight joint at lap locations without sealant.
Brand Equivalence — Lead Code System
Code designation is a material property — Code 4 from Austral and Code 4 from Calder are the same material thickness and weight. Select by supplier availability and trade pricing.
| Code | Austral Lead | Calder Industrial | Notes |
|---|---|---|---|
| Code 3 (1.32mm / 14.97 kg/m²) | Yes | Yes | Minimum code for small soakers |
| Code 4 (1.80mm / 20.41 kg/m²) | Yes | Yes | Standard code for step and counter-flashing |
| Code 5 (2.24mm / 25.40 kg/m²) | Confirm | Yes | For chimney back gutters and complex chimney work |
Product Reference
3 products — 2 brands — lead sheet step and counter-flashing — scroll to view all
Austral Lead Code 3 Sheet (1.32mm / 14.97 kg/m²)
Lead sheet — Code 3 — 1.32mm — AS 3703 / BS EN 12588
System Description
Austral Lead Code 3 sheet is the lightest lead sheet commonly used in roofing applications in Australia. At 1.32mm thickness and 14.97 kg/m², Code 3 is the minimum standard for small soaker-type step flashings where the individual soaker pieces are kept to a short length and limited plan area. For Code 3 lead sheet, the BS EN 12588 and AS 3703 lead code system specifies a maximum soaker size to limit the weight of lead on any single fixing point and to prevent thermal expansion fatigue at the fixing — Code 3 soakers should generally not exceed 150mm in length. In practice, Code 3 lead is less commonly specified for step and counter-flashing on Australian pitched tiled roofs than Code 4, which provides better durability and greater forming weight for standard-size step flashings. Code 3 may be specified by a heritage consultant or roof plumber where the original specification used Code 3 and the remediation requires matching the original material, or where a very lightweight lead soaker is required for a specific tile profile with minimal bearing area. For standard step and counter-flashing on heritage tiled roofs, specify Code 4. Confirm with Austral Lead & Metals before ordering.
Technical Properties
- Austral Lead Code 3 sheet — 1.32mm nominal thickness — 14.97 kg/m² — AS 3703 compliant — BS EN 12588 Code 3
- Minimum code for roofing step flashings — appropriate for small individual soakers with a short maximum length (generally 150mm maximum)
- Malleable and ductile — can be dressed by hand onto irregular profiles and around corners without cracking — no sheet metal folder required
Limitations
- Code 3 is the minimum code for step flashings — where soakers exceed 150mm in length or where the step flashing has significant plan area, specify Code 4 instead
- Heavier than Colorbond or aluminium — additional roof load must be considered in structural assessment, particularly on heritage buildings with existing loading constraints
- Lead handling requires appropriate PPE — wear gloves, do not eat, drink, or smoke when handling lead — wash hands after work — refer to manufacturer MSDS
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
Austral Lead Code 4 Sheet (1.80mm / 20.41 kg/m²)
Lead sheet — Code 4 — 1.80mm — AS 3703 / BS EN 12588 — standard specification
System Description
Austral Lead Code 4 sheet is the standard specification for step and counter-flashing, chimney flashings, and saddle flashings on pitched tiled roofs in Australia where lead is specified. At 1.80mm thickness and 20.41 kg/m², Code 4 provides the durability and forming weight required for standard step flashings on both soaker and continuous step flashing designs. Code 4 is the most commonly specified lead sheet code for this application in Australian heritage building specifications and by experienced roof plumbers working on heritage-listed and high-specification residential tiled roofs. Code 4 is appropriate for step flashing soakers up to 250mm length, for continuous step flashings, and for counter-flashings into mortar joints at masonry chimney and wall abutments. Lead is specified for these applications primarily on heritage buildings where the original material was lead and the heritage authority requires matching material to be used in the remediation, and on high-specification new and remediation projects where the roof plumber or specifier considers lead to be the optimal material for durability and self-sealing at overlaps. Austral Lead & Metals is the primary Australian manufacturer of lead sheet to AS 3703 and BS EN 12588. Fixings must be copper or stainless steel. Lead must not be painted. Installed by an experienced roof plumber.
Technical Properties
- Austral Lead Code 4 sheet — 1.80mm nominal thickness — 20.41 kg/m² — AS 3703 compliant — BS EN 12588 Code 4
- Standard code for step flashings, counter-flashings, chimney flashings, and saddle flashings on Australian tiled roofs
- Suitable for soakers up to 250mm length and for continuous step flashing installations
Limitations
- Heavier than Colorbond or aluminium — Code 4 lead at 20.41 kg/m² imposes a significantly higher roof load than steel or aluminium flashings — confirm with structural engineer on heritage buildings with existing loading constraints
- Lead handling requires appropriate PPE — gloves mandatory — do not eat, drink, or smoke when handling lead — wash hands thoroughly after handling — refer to Austral Lead MSDS
- Lead waste must be disposed of according to local state/territory hazardous waste regulations — do not place lead offcuts in general skip bins or waste
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
Calder Industrial Lead Sheet
Lead sheet — Code 3, 4 and 5 — alternative supplier — AS 3703 / BS EN 12588
System Description
Calder Industrial Materials is an alternative supplier of lead sheet in Australia, supplying Code 3, Code 4, and Code 5 gauges to AS 3703 and BS EN 12588. Calder Industrial is commonly used as an alternative to Austral Lead where trade pricing, stock availability, or local supply chain factors make Calder the preferred source. The product performs identically to Austral Lead sheet at each code designation — the lead code system (Code 3, 4, 5) defines thickness and weight per square metre regardless of manufacturer, and both Austral and Calder manufacture to the same BS EN 12588 and AS 3703 standards. Code 5 lead sheet (2.24mm, 25.40 kg/m²) is available from Calder and is used for chimney back gutters, complex chimney flashings, and other applications where a heavier gauge is required — Code 5 is not typically used for standard step flashings but is listed here because Calder supplies the full range. For standard step and counter-flashing on pitched tiled roofs, specify Code 4 from either Austral or Calder. The choice between Austral and Calder for a given project is typically made on the basis of local trade pricing and stock availability. All lead sheet handling, forming, fixing, and disposal requirements are the same regardless of manufacturer — refer to the Code 3 and Code 4 product entries above for handling and installation notes.
Technical Properties
- Calder Industrial lead sheet — Code 3 (1.32mm / 14.97 kg/m²), Code 4 (1.80mm / 20.41 kg/m²), Code 5 (2.24mm / 25.40 kg/m²) — AS 3703 / BS EN 12588
- Alternative to Austral Lead & Metals — same code system, same thickness and weight per code designation, same material properties
- Code 5 available for chimney back gutters, complex chimney and hip flashings where heavier gauge is required
Limitations
- All lead handling, forming, fixing, and disposal requirements apply equally to Calder lead as to Austral Lead — refer to Code 3 and Code 4 product entries for full limitations
- Code 5 is heavier than Code 4 and increases roof loading further — confirm structural capacity before specifying Code 5 in remediation of existing heritage roofs
- Confirm current product availability, code range, and pricing with Calder Industrial before ordering — product range and stock vary by state
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
System Comparison
Side-by-side comparison of lead sheet step and counter-flashing options by code. Confirm all product selections against the current supplier data before specifying.
| Product | Code | Thickness | kg/m² | Applications | Heritage | Forming method |
|---|---|---|---|---|---|---|
| Austral Lead Code 3 | Code 3 | 1.32mm | 14.97 kg/m² | Small soakers — step flashings (minimum code) | Yes | Hand-formed and dressed by roof plumber |
| Austral Lead Code 4 | Code 4 | 1.80mm | 20.41 kg/m² | Step flashings, counter-flashings, chimney flashings — standard specification | Yes | Hand-formed and dressed by roof plumber |
| Calder Industrial (Code 3, 4, 5) | Code 3, 4, 5 | 1.32mm / 1.80mm / 2.24mm | 14.97 / 20.41 / 25.40 kg/m² | All lead flashing applications — same scope as Austral — Code 5 for chimney back gutters | Yes | Hand-formed and dressed by roof plumber — same method as Austral |
Do not confuse lead step flashing with:
- Lead-headed copper nails — a type of nail used to fix slates and tiles, not a flashing product — do not confuse with lead sheet for step flashings
- DPC lead (damp-proof course lead) — a sub-slab or cavity wall DPC product, not a roof flashing material — different product and application entirely
- Colorbond step flashing (Lysaght/BlueScope or Stramit) — factory pre-painted steel, not lead — listed on the Step — Colorbond page — cannot be formed and dressed the same way as lead
- Aluminium step flashing (Capral, Metalcorp, or custom fabricator) — lighter and painted to colour, but not malleable like lead and does not self-seal at overlaps — listed on the Step — aluminium page
- Note: lead is malleable and self-sealing at overlaps — unlike Colorbond or aluminium — this is a primary technical advantage for complex flashings and heritage applications. Lead must not be painted.
Disclaimer
Lead handling requires appropriate PPE. Lead waste must be disposed of according to local regulations. Step flashing design must comply with tile manufacturer requirements and AS 3703. Final product selection must be confirmed against the current supplier data sheet and project specification. Installed by an experienced roof plumber. Do not rely on this reference as a substitute for professional engineering or roofing consultant advice.