Repair Systems — 03 — Facade & External Envelope
Duplex coated steel channel lintel
Technical product reference for duplex coated steel PFC channel lintels for masonry facade remediation on Australian Class 2 strata buildings. Covers HDG plus epoxy paint PFC channel lintels for wide inland masonry openings. Structural engineer specification is mandatory for all channel lintel replacements.
What is a duplex coated steel channel lintel?
A duplex coated steel channel lintel is a hot-dip galvanised (HDG) parallel flange channel (PFC) section with an epoxy paint overcoat applied over the zinc coating. PFC channel provides a substantially higher section modulus than equal angle sections of the same nominal height, making it the appropriate lintel choice for wide masonry openings — garage doors, large window openings, or heavily loaded facade zones — in inland C2/C3 environments. The duplex system provides 40–50 year service life inland.
Product Reference
2 supplier systems — duplex coated PFC channel lintels — scroll to view all
InfraBuild — Duplex coated PFC channel lintel — back-to-back or single — wide openings
Duplex coated PFC channel lintel — HDG + epoxy — wide openings — inland
System Description
InfraBuild supplies hot-dip galvanised parallel flange channel (PFC) sections compliant with AS/NZS 4680, finished with an epoxy paint overcoat to form a duplex coating system for wide or heavily loaded masonry lintel applications. PFC channel provides a substantially higher section modulus than equal angle sections of the same nominal height — used for garage door openings, wide window openings, or structurally loaded facade zones in inland buildings where an angle section cannot achieve the required span or load capacity. Channel lintels may be installed as single sections or as back-to-back pairs bolted together for very wide spans or high loads. Back-to-back channel lintels require an engineer-designed connection — bolt size, spacing and clamping force must be specified for the design loads. The HDG + epoxy duplex system provides 40–50 year inland service life. Not suitable for coastal or C4/C5 environments.
Technical Properties
- Higher section modulus than equal angle — PFC channel significantly outperforms angle sections for long spans and heavy masonry loads
- Back-to-back configuration available — pairs of PFC channels bolted together for wide openings where a single channel is insufficient
- HDG + epoxy paint duplex system — AS/NZS 4680 compliant zinc coating plus epoxy paint overcoat for 40–50 year inland service life
Limitations
- Not suitable for coastal, marine or C4/C5 environments — specify grade 316L stainless steel channel or back-to-back angle for coastal applications
- Structural engineer must design and certify the channel section, span, bearing and any back-to-back connection — do not select section without engineering confirmation
- Back-to-back channel connection must be engineer-designed — bolt size, spacing and clamping force must be specified; do not use back-to-back channel without a confirmed connection design
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
State-based masonry lintel fabricators — cut-to-length duplex PFC channel lintels
Duplex coated PFC channel lintel — cut to length — local fabrication — engineer's drawings
System Description
State-based masonry lintel fabricators supply cut-to-length duplex coated PFC channel lintels fabricated to the structural engineer's drawings for wide masonry opening applications in inland buildings. This approach is used when the required channel length or configuration is not available as standard stock, or when back-to-back channel pairs need to be pre-assembled and coated as a unit before delivery. The fabricator hot-dip galvanises the cut sections and applies an epoxy paint overcoat per the project specification. For back-to-back channel assemblies, the fabricator bolts the sections together per the engineer's connection design before galvanising — this ensures the bolt holes and contact surfaces are also galvanised. Request a fabrication and coating certificate confirming AS/NZS 4680 compliance before accepting delivery. Not suitable for coastal environments — specify stainless for all coastal channel lintel applications.
Technical Properties
- Cut to exact length — avoids waste and ensures consistent bearing length at both ends per the engineer's specification
- Back-to-back assemblies can be pre-fabricated and duplex coated as a unit — bolt holes and contact surfaces included in the HDG bath
- Fabricated to engineer's drawings — channel section, length, back-to-back bolt pattern and bearing plates per the structural design
Limitations
- Confirm the fabricator's HDG bath can accommodate the required channel dimensions and lengths before ordering
- Structural engineer's drawings must be provided before ordering — back-to-back bolt connection must be engineer-designed
- Request fabrication and coating certificate confirming AS/NZS 4680 compliance before accepting delivery
PROCUREMENT SOURCES
Confirm suitability with the current manufacturer TDS before specifying or applying.
System Comparison
Side-by-side comparison of duplex coated PFC channel lintel systems. Confirm all selections against the structural engineer's design before ordering.
| Supplier | Product | Coating | Sections | Service life | Distribution | Key feature | Primary use |
|---|---|---|---|---|---|---|---|
| InfraBuild | Duplex PFC channel lintel | HDG + epoxy paint | Standard PFC range | 40–50 yr inland C2/C3 | National — steel merchant | High section modulus — wide spans | Wide openings — inland |
| State fabricators | Cut-to-length duplex PFC channel | HDG + epoxy — per spec | Engineer-specified | 40–50 yr inland C2/C3 | State-based — local fabrication | Back-to-back pre-assembled | Non-standard wide openings |
Do not confuse duplex channel lintel with:
- Duplex angle lintel — equal angle has lower section modulus than PFC channel; use angle where the span and load can be achieved with an angle section — reserve channel for wide or heavily loaded openings
- Duplex flat bar lintel — flat bar has the lowest section modulus of the three profiles; restricted to shallow rebate short spans under 2 m — not a substitute for channel at wide openings
- Stainless steel back-to-back angle lintel — grade 316L stainless for coastal and marine environments; required for wide openings within 1 km of the coast or in C4/C5 zones
Disclaimer
This page provides general technical information only. Duplex coated channel lintel design, section size, back-to-back connection, bearing length and installation must be specified and certified by a structural engineer per AS 4100 and AS 3700.