Commercial Re-roofs
Allied Commercial specialises in commercial re-roofs and roof replacements with minimal business disruption, using high-grade materials and advanced installation techniques.
Overview
A commercial re-roof is one of the most significant capital expenditure decisions a building owner or manager will make. The new roof must perform for 25-40 years, withstand the wind, rain, hail, and UV exposure specific to its geographic location, and do so without disrupting the business operations happening beneath it. Allied Commercial's re-roofing methodology is designed to deliver exactly that outcome.
We begin every re-roof project with a structural assessment of the existing roof frame -- purlins, battens, rafters, and connections. This is not optional. If the structure beneath has deteriorated (rust, termite damage, inadequate original sizing), installing new sheeting on a compromised frame is a waste of money. Our structural engineers assess the frame against AS 4100 (Steel Structures) and the current wind loading requirements of AS 1170.2, and any necessary strengthening is included in the scope.
Material selection is guided by AS 1562.1 (Metal Roof and Wall Cladding) and the manufacturer's installation requirements. We are BlueScope accredited installers, meaning our Colorbond and Zincalume installations are backed by the full manufacturer warranty programme -- up to 25 years on Colorbond steel in standard environments. We also install architectural profiles (standing seam, concealed-fix longline) for premium commercial and retail applications.
Our installation methodology strips the existing roof in controlled sections to maintain weather protection throughout the project. Anti-condensation blankets, new flashings, gutters, downpipes, skylights, and ventilation are installed as part of the re-roof scope. Every project includes a height safety assessment, and we design and install anchor points, static lines, and walkways as part of the re-roofing programme -- so the new roof is compliant from day one.
Key Benefits
- Staged installation keeps your building weatherproof throughout
- BlueScope manufacturer warranty up to 25 years on Colorbond
- Height safety designed and installed as part of every re-roof
- Structural frame assessment prevents installing on compromised framing
- Architectural profiles available for premium commercial applications
- Minimal disruption to business operations with controlled staging
Product & Service Scope
What we deliver
Full strip-and-replace re-roofing programmes
BlueScope Colorbond and Zincalume accredited installer
Architectural profiles -- standing seam, concealed-fix, longline
Structural frame assessment and strengthening
Anti-condensation insulation blanket installation
Complete flashing, gutter, and downpipe renewal
Skylight replacement and installation
Height safety system design and install (included)
Material & Installation Standards
Australian Standards compliance
The primary standard governing commercial metal roofing. Specifies minimum pitch, fastener requirements, flashing details, thermal movement provisions, and wind uplift resistance for all metal roof installations.
Determines the design wind speed for the building location and terrain category, which directly dictates fastener spacing, sheet gauge, and fixing patterns at ridges, eaves, and corners.
Referenced for assessment of existing steel roof framing (purlins, battens, rafters) and design of any structural strengthening required before the new roof is installed.
Governs selection and installation of waterproofing membranes at roof penetrations, parapets, and box gutters where standard flashing details are insufficient.
As an accredited BlueScope installer, our Colorbond installations qualify for the manufacturer warranty programme -- up to 25 years depending on product and environment.
Material Specifications
At a glance
Installation Methodology
How we deliver
Structural Assessment
Engineers inspect the existing roof frame -- purlins, battens, connections, and bearings. Wind loading is calculated to current AS 1170.2 and any structural deficiencies are identified for rectification.
Specification & Procurement
Material selection, profile, colour, gauge, and flashing details are specified per AS 1562.1. Materials are ordered direct from BlueScope/Lysaght/Stramit with manufacturer traceability documentation.
Staged Strip & Install
The existing roof is stripped in controlled sections (typically 2-3 bays at a time) to maintain weather protection. New insulation, sheeting, flashings, and gutters are installed progressively. No area is left exposed overnight.
Height Safety & Handover
Anchor points, static lines, and walkways are installed. The completed roof is leak-tested, manufacturer warranties are registered, and handover documentation including as-built drawings is delivered.
FAQ
Common questions
How long does a commercial re-roof take?
The duration depends on roof area, complexity, and weather. A typical 1,000-2,000 sqm single-storey commercial roof takes 2-4 weeks. Our 320 Adelaide Street project -- 1,300 sqm across multiple levels with four different profiles, scaffolding coordination, and night-time crane lifts -- took 12 months due to the complexity and inner-city constraints. We provide a detailed programme at quoting stage with weather contingency allowances. All re-roofs are staged so that your building remains weatherproof throughout the project.
What roofing materials do you recommend?
For most commercial applications in Queensland, Colorbond steel is the optimal choice. It offers a proven track record in Australian conditions, a comprehensive colour range, excellent corrosion resistance (Zincalume-coated base), and manufacturer warranty support of up to 25 years. For architectural applications where aesthetics are paramount, we recommend concealed-fix standing seam profiles (Lysaght 305 Longline or equivalent) which provide a clean, modern appearance with no visible fasteners. For industrial buildings prioritising cost, Zincalume (unpainted) provides excellent durability at a lower price point.
Do you install height safety as part of the re-roof?
Yes, always. Every Allied re-roof project includes a height safety assessment, and we design and install anchor points, static lines, and walkways as part of the roofing scope. This is not an optional extra -- it is a standard inclusion. The cost of installing height safety during a re-roof is a fraction of retrofitting it afterwards (the roof is already open, the crew is already on site, and the anchors can be fixed directly to structure rather than through finished roofing). The height safety system is certified to AS/NZS 1891 on completion.
Industries
Need Commercial Re-roofs?
Contact us for a no-obligation quote or free site inspection.