Lysaght TRIMDEK® Roofing & Walling — Hi-Rib Profile for Residential and Commercial
Versatile hi-rib trapezoidal profile for roofing and walling. 29 mm rib height, 762 mm nominal cover width, suitable for low-pitch applications subject to design provisions.
- BMT Range
- 0.42 – 0.48 BMT
- Category
- roofing
- Available Colours
- Monument, Ironstone, Dune, Surfmist, Woodland Grey, Shale Grey +2 more
- 29 mm hi-rib for superior spanning
- 762 mm nominal cover width
- COLORBOND Activate coating
- Suitable for 2° minimum pitch
- Matching ridge, hip and valley flashings
POA
Price on Application
This product is custom-cut, large-volume or project-specific. Submit a quote request and our trade desk will respond within 2 business hours.
Overview
Lysaght TRIMDEK® is one of Australia's most widely used roofing and walling profiles. The trapezoidal geometry — 29 mm nominal rib height with subtle square-fluted pans — provides greater spanning capacity than corrugated sheet, reducing purlin spacing on many jobs. Manufactured from COLORBOND or ZINCALUME steel to AS/NZS 1397 G550 (550 MPa minimum yield), TRIMDEK® suits residential, commercial and agricultural buildings.
Per Lysaght specifications: 762 mm nominal cover width (±4 mm), 0.42 and 0.48 BMT, minimum roof pitch 2° subject to design provisions. CSA supplies TRIMDEK® across the COLORBOND colour range with standard and project lengths quoted at order acceptance.
Technical Specifications
| Profile type | Trapezoidal hi-rib with square-fluted pans, roofing & walling |
|---|---|
| Nominal cover width | 762 mm (±4 mm) |
| Rib height | 29 mm |
| Base metal thickness | 0.42 mm and 0.48 mm (roofing); 0.35–0.42 mm walling |
| Mass (COLORBOND) | 0.42 BMT ≈ 4.35 kg/m²; 0.48 BMT ≈ 4.93 kg/m² |
| Minimum roof pitch | 2° subject to Lysaght design provisions |
| Length tolerance | Custom cut; +0 / −15 mm |
| Fixing method | Pierce-fixed through the pans |
| Steel base | BlueScope COLORBOND or ZINCALUME steel |
|---|---|
| Finishes | COLORBOND Classic, Matt, Metallic, Coolmax, Ultra; ZINCALUME |
| Yield strength | G550 (550 MPa minimum yield) |
| Coating | AM100 / AZ125 metallic alloy coating with Activate technology |
| Steel standard | AS 1397:2021 |
| Paint standard | AS/NZS 2728:2013 |
Fixing & Fasteners
- Roofing screws to AS 3566 with EPDM sealing washers, fixed through the pan of every second rib.
- Class 3 fasteners for general use; Class 4 / Type 316 stainless within ~1 km of the coast.
- Support thickness of 1.0 mm BMT assumed in standard span tables — refer to TOPSPAN guide for lighter battens.
Matching Accessories
- Matching ridge, hip and valley flashings
- Barge / gable rolls and apron flashings
- COLORBOND rainwater (fascia, gutter, downpipe)
- Sealing washers, foam closures, touch-up paint
Installation & Handling
- Support sheets along their length when handling; lift on edge with two people to avoid kinking.
- For roofs under 15° pitch, turn up the high end of each sheet to stop water tracking under flashings.
- Stitch side laps at mid-span on long runs and high-wind sites to maintain a weather-tight joint.
Warranty
Made from COLORBOND or ZINCALUME steel and backed by BlueScope warranties for eligible applications (corrosion and paint), subject to environment and correct installation.
Register and confirm warranty eligibility through BlueScope. Manufacturer warranties do not affect your rights under the Australian Consumer Law.
Compliance
Standards & Certifications
High-tensile steel base
Cold-rolled from G550 steel (550 MPa minimum yield strength) with a metallic alloy coating, manufactured by BlueScope to the relevant Australian Standard.
AS 1397:2021
COLORBOND prepainted finish
COLORBOND prepainted steel finishes are manufactured to the Australian Standard for prepainted steel, incorporating Activate technology for corrosion resistance and (in core colours) Thermatech solar reflectance.
AS/NZS 2728:2013
Non-combustible material
Steel made by BlueScope has an Ignitability, Spread-of-Flame and Heat-Evolved index of 0 (zero), so it may be used wherever a non-combustible material is required under the National Construction Code (NCC 2022 C2D10).
AS/NZS 1530.3
Suitable for bushfire-prone areas
Steel roofing and walling can be specified from BAL-12.5 up to BAL-FZ (Flame Zone) using compliant system details under AS 3959 and the NASH Bushfire Standard, which the NCC references as a Deemed-to-Satisfy solution.
AS 3959 / NASH
Designed and installed to standard
Metal roofing and wall cladding is designed, tested and installed to the metal roofing/cladding code, with wind actions assessed to the wind loading standard.
AS 1562.1 / AS/NZS 1170.2
Datasheets, Guides & Certificates
Manufacturer documentation for specification and compliance. Links open the original source documents.
Dimensions, masses, tolerances and maximum support spacings.
Profile overview, cover width and finishes.
Material specifications, support spacings, overhangs, fixing and handling for Lysaght profiles.
NCC clauses, applicable standards and warranty ranges for Lysaght steel roofing and walling.
Check eligibility and register a COLORBOND / ZINCALUME steel warranty for your project.
Colours Available
Use Cases
- Residential roofing
- Commercial warehouse
- Agricultural shed
- Pergola and patio cover
- Feature wall cladding
Applicable Standards
- AS 1562.1
- AS/NZS 1397
- NCC Section J
FAQ
Lysaght TRIMDEK® — Frequently Asked Questions
How low a pitch can TRIMDEK go to?
TRIMDEK can be laid to a minimum roof pitch of 2° subject to Lysaght design provisions — significantly lower than corrugated, which is why it suits modern low-pitch homes and light commercial roofs.
Does TRIMDEK span further than corrugated?
Yes. The 29 mm hi-rib gives greater spanning capacity than corrugated, so you can use wider support spacings and fewer purlins. Refer to the Lysaght brochure span tables for your wind classification.
Can TRIMDEK be used for walling?
Yes — TRIMDEK is a roof and wall profile. Walling is commonly 0.35–0.42 mm BMT, roofing 0.42–0.48 mm BMT.
Resources
Guides for specifying and ordering
Selection Guide
How to Choose a Roof Profile: Corrugated, Trimdek, Spandek and Klip-Lok
A practical guide to choosing a steel roof profile in Australia. Compare corrugated, Trimdek, Spandek, Klip-Lok and Monoclad on pitch, span, cost and appearance.
Read guideHow-To
Roof Sheet Takeoff and Ordering: How to Measure and Buy Roofing
How to measure a roof and order the right number of steel sheets, screws, flashings and gutters. Cover widths, waste allowance and a worked takeoff example.
Read guideColour Guide
COLORBOND Colour Selection Guide for Australian Roofs
How to choose a COLORBOND colour for your roof. Heat, neighbourhood character, council rules and the full 20-colour palette explained, with light and dark trade-offs.
Read guideMore from Lysaght
View all
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