Commercial roofs fail differently from house roofs. Low pitches, long sheet runs, large box gutters, plant and equipment penetrations, and roof spaces with very different air conditions all change the risks. A leak over a warehouse rack, a retail floor or a server room costs far more than the repair itself, so the goal is to find problems early and fix them with minimum disruption.
We work on commercial, light industrial and multi-unit residential roofs across Auckland, from a single box gutter repair to full re-roofs staged over occupied buildings. Property managers, body corporates and business owners use us for planned maintenance, condition reports and capital works, and we price ongoing work at account rates.
Pricing: every roof gets a free on-site measure and an itemised written quote, with a fixed price agreed before any work starts.
Common problems on commercial roofs
Most commercial roof leaks we are called to trace back to a handful of causes:
- Box and internal gutters that are undersized, blocked or have no overflow
- Corroded laps, fixings and sheet ends on long, low-pitch runs
- Failed seals around plant, ducts, skylights and later penetrations added by other trades
- Translucent sheeting that has become brittle and is now a fall-through hazard
- Condensation dripping inside large, unlined steel-framed buildings
- Membrane roofs with ponding, open seams or lifted edges
What we do
Commercial work ranges from reactive repairs to full replacement. For each site we start with a condition inspection and written report, then agree a scope and programme with you. Re-roofs on occupied buildings are staged so only a section is open at a time, with weather contingency and protection for stock and equipment below. Where membrane is the right answer on flat areas, our membrane roofing team handles those sections to the same programme.
For portfolios and body corporates we set up maintenance programmes: scheduled gutter and outlet clearing, washing of unwashed areas to keep material warranties valid, fixings checks and photo reports after each visit. Regular condition reports also give you a capital plan, so a re-roof is a budgeted project rather than an emergency.
How It Works
Materials and design for large roofs
Large commercial roofs usually rely on trapezoidal or standing seam profiles, because they carry more water and can be laid at lower pitches. The NZ Metal Roof and Wall Cladding Code of Practice sets minimum pitches by profile, down to 3 degrees for deeper trapezoidal and standing seam profiles, and gives run lengths after which the profile's water capacity needs checking. Long runs also need allowance for thermal expansion.
Exposure matters as much on a commercial roof as on a home. COLORSTEEL MAXAM is designed for most New Zealand environments, while ALTIMATE is designed for extremely severe marine sites. Industrial sites near the harbour, the airport or busy roads can also have local conditions that affect the choice. Our COLORSTEEL longrun page goes into product and profile options in more depth.
Condensation is a specific risk in large steel-framed buildings. BRANZ research into large-cavity institutional roofs found moisture collecting on steel purlins when a continuous underlay trapped condensation, so the underlay, insulation and ventilation design need to work together.
Box gutters and drainage
On commercial buildings the gutter is often inside the building line, so an overflow lands inside. BRANZ recommends designing internal gutters for a higher rainfall intensity than external gutters, and good practice includes overflows sized to take the full flow if an outlet blocks. Many older box gutters were never sized for the roof area they now serve, particularly after extensions. We check capacity, outlets and overflows as part of every commercial inspection, and our spouting service covers replacement and relining.
Health and safety, consent and compliance
Working at height on commercial roofs needs proper planning. WorkSafe guidance sets out a hierarchy of controls, with edge protection and scaffolding preferred over harnesses, and edge protection systems designed to AS/NZS 4994. Fragile roofing and translucent sheets need covers or barriers. Every job has a site-specific safety plan, and we coordinate site inductions, permits and hazard registers with your facilities team.
Replacing roofing with a comparable material can fall under the Schedule 1 exemption for any building type, as long as the existing roof has met its durability requirement. Changes to structure, materials or drainage may need building consent and, on larger buildings, specific design. Restricted building work rules apply to residential buildings, so multi-unit residential roofs can also need a Licensed Building Practitioner for consented work. We confirm the compliance path before pricing.
Pricing and account work
Commercial projects are priced on a defined scope after an inspection. The main cost drivers are roof area, access and edge protection, the need to work after hours or around operations, removal and disposal, gutter and structural repairs, and the product specification. For ongoing maintenance clients we agree account rates and a schedule. To arrange a site visit, use our contact page.
Why Choose Cheeky's Roofers for Commercial Roofing
Staged around your operations
Re-roofs are sequenced so only one section is open at a time, with stock and staff protected below.
Reports that support budgets
Condition reports with photos and ranked recommendations help property managers plan capital works.
Safety planned, not improvised
Site-specific safety plans, edge protection and coordination with your facilities team on every job.
Maintenance that protects warranties
Scheduled washing and gutter clearing that keep material warranty conditions met.
Account rates
Agreed rates and a single point of contact for portfolio and body corporate clients.
Commercial Roofing FAQs
Can you re-roof while our building is in use?
Yes. We stage the work so only one section is open at a time, plan around weather, and protect the space below. Some tasks may be scheduled outside your business hours.
Do commercial re-roofs need building consent?
Like-for-like replacement can be exempt under Schedule 1 for any building, provided the old roof met its durability requirement. Changes to structure, materials or drainage may need consent and specific design.
Why does our warehouse drip inside when it is not raining?
Usually condensation forming under the roofing or on purlins in cold conditions. BRANZ has researched this in large steel-framed roofs. The fix is in insulation, underlay and ventilation design, not sealant.
Do you offer maintenance contracts?
Yes. We set up scheduled inspections, gutter clearing and washing with photo reports after each visit, at agreed account rates.
What is the lowest pitch a metal roof can be?
It depends on the profile. The NZ Metal Roof and Wall Cladding Code of Practice allows deeper trapezoidal and standing seam profiles down to 3 degrees, with run length limits.
Do you work on body corporate and apartment roofs?
Yes. Multi-unit residential roofs often need consent and Licensed Building Practitioner involvement for larger work, which we handle as part of the project.
Commercial Roofing by Area
Local commercial roofing information for your part of Auckland:
Related Roofing Services
See the re-roofing cost guide or every service we offer.
Sources and further reading
- NZ Metal Roof and Wall Cladding Code of Practice: roof pitch
- WorkSafe: Working on roofs good practice guidelines
- BRANZ SR289: Remediating condensation problems in large-cavity, steel-framed institutional roofs
- BRANZ: Internal gutters and flow capacity
- COLORSTEEL: product range and environments
- building.govt.nz: Exemption 1.1 general repair, maintenance and replacement
- building.govt.nz: Restricted building work