Corrugated roof sheets are rolled metal or plastic panels with a repeating wave profile that sheds water fast and spans purlins cheaply. Steel sheets such as Custom Orb in Colorbond usually cost about $20–$40 per lineal metre supplied (indicative — get itemised quotes), while plastic sheets suit patios that need daylight.
We install and replace them across Sydney, so this guide covers the profiles, real costs, fixing rules and the traps that cause leaks on older homes.
Key points
- Custom Orb is the classic corrugated profile for Australian homes, and Colorbond steel is the default material for a long-lasting re-roof.
- Steel sheets are priced per lineal metre and installed prices vary with pitch, access and flashings, so compare itemised quotes on the same scope.
- Plastic and polycarbonate corrugated sheets let light through, but they need a minimum 5° pitch and the manufacturer’s own fixings to keep the warranty.
- Very old corro can be asbestos cement, so never drill, cut or wash it until a licensed assessor has tested it.
What are corrugated roof sheets?
Corrugated roof sheets get their strength from the wave profile, which lets a thin steel or plastic sheet span between purlins without sagging. The pattern also channels rain towards the gutter quickly, which is why the profile has lasted on Australian sheds, verandahs and houses for well over a century.
Most homeowners search for the same thing under different names, so the table below translates the common terms.
| Term | What it means | Why it matters |
|---|---|---|
| Corrugated iron roof sheets | Old name for galvanised steel sheets; today the sheets are Zincalume or Colorbond steel | Tells you whether a quote is for modern coated steel or recycled old iron |
| Corro, CGI roof sheets | Trade slang for corrugated galvanised iron | Same product family; ask which coating and base metal thickness you are getting |
| Custom Orb | Lysaght’s rounded corrugated profile, often written Custom Orb cladding when used on walls | The profile most Sydney re-roofs and sheds are matched to |
| Corrugated Colorbond | Custom Orb or similar profile in factory-painted Colorbond steel | Gives a baked-on colour finish and a manufacturer warranty on the coating |
| Plastic roofing sheets | Polycarbonate, PVC or fibreglass sheets in corrugated profiles | Used for skylight strips and light-filled patios, not whole house roofs |
- Material: steel sheets are zinc or aluminium-zinc coated, with Colorbond adding a painted finish for colour and extra protection.
- Profile: Custom Orb has a rounded, traditional wave, while Trimdek and other trapezoidal profiles have flat pans between the ribs.
- Length: steel is rolled to order, so you can usually avoid end laps on a standard house roof by specifying full-length sheets.
- Weight: light sheeting needs lighter framing than tiles, which is why many re-roofs over old tile roofs need a structural check first.
Types of corrugated roof sheets
| Type | Best for | Lifespan and strength | Price band |
|---|---|---|---|
| Colorbond Custom Orb | Houses, verandahs, sheds, heritage-style roofs | Long life with correct fixings and coastal care; strong and light | $$ (about $20–$40 per lineal metre supplied) (indicative — get itemised quotes) |
| Zincalume corrugated | Sheds, farm buildings, budget roofs | Unpainted metallic finish; fine inland, check coastal suitability | $–$$ (indicative — get itemised quotes) |
| Galvanised corro (reused or new) | Restoration of older homes | Rust returns once the zinc wears off; needs painting | $–$$ (indicative — get itemised quotes) |
| Polycarbonate corrugated | Patio roofs, carports, skylight strips | Tough, light-transmitting, needs pitch of 5° or more | About $72 for a 3.6 m Laserlite 3000 sheet |
| PVC roofing sheets | Low-cost patio and shed cover | Less impact resistant than polycarbonate; can discolour | $ (indicative — get itemised quotes) |
| Insulated corrugated roofing | Patios and extensions that need a cooler space | Foam core cuts heat and noise | $$$ (indicative — get itemised quotes) |
Compare Colorbond roof sheets
Colorbond roof sheets come in several profiles and colours, and the Colorbond roof sheets guide sets out how to choose between them.
Check Custom Orb details
The profile’s rib shape, cladding uses and matching accessories are covered in our Custom Orb profile guide.
Match corrugated Colorbond roofing to the house
Colours, fixings and heritage considerations are in the Colorbond corrugated roofing guide.
Confirm the Colorbond sheet width
Cover width decides how many sheets you order, and the Colorbond sheet width guide shows how to measure it.
Corrugated roof sheets sizes, coverage and dimensions
Sheet size drives both ordering and cost, so measure the roof plane in lineal metres and then divide by the cover width, not the overall width.
| Item | What to know | How to check it |
|---|---|---|
| Corrugated roof sheets dimensions (steel) | Overall width is larger than cover width because the side lap overlaps | Read cover width on the manufacturer’s current data sheet before ordering |
| Corrugated iron sheet coverage | Divide roof width by the cover width, then round up to whole sheets | Add a spare sheet for cutting around penetrations and hips |
| Laserlite polycarbonate corrugated | Sheet is 840 mm wide with 755 mm cover and comes 1.8 to 9.0 m long | Confirm the length against your purlin layout |
| Roof iron profiles | Custom Orb, Trimdek, Classic and other profiles are not interchangeable | Match the profile on the adjoining roof exactly |
| Roofing sheets design | Rib shape, pan width and colour change how the roof looks and reads in the street | Hold a full-length sample against the house in daylight |
Corrugated roof sheets cost in Sydney
Pricing moves with steel prices, so treat these as a guide only and ask for the quote to be itemised by sheets, flashings, labour and disposal.
| Item | Typical range (AUD, Oct 2026) | Notes |
|---|---|---|
| Corrugated iron price per metre (Zincalume or galvanised) | $15–$30 per lineal metre (indicative — get itemised quotes) | Cheapest option; coating and base metal thickness vary by brand |
| Colourbond price and Colorbond pricing (Custom Orb) | $20–$40 per lineal metre (indicative — get itemised quotes) | Painted finish, wider colour choice and a coating warranty |
| Zinc corrugated iron price | Close to the Zincalume range (indicative — get itemised quotes) | Check the actual coating on the quote, because names are used loosely |
| Colorbond re-roof, supplied and installed | $90–$180 per m² (indicative — get itemised quotes) | Includes removal, battens, flashings and gutters on simple roofs |
| Polycarbonate patio roof, installed | $220–$360 per m² (typical $280) | Includes posts, footings and frame |
| Corrugated plastic roof sheets | Cheaper than polycarbonate per sheet (indicative — get itemised quotes) | Short life if the UV layer is poor |
- Roof shape: hips, valleys and dormers add cutting, flashings and labour compared with a plain gable.
- Old roof removal: stripping tiles or old sheets, and tipping fees, can be a large share of the job.
- Access: two-storey homes, tight side access and steep pitches add scaffold or edge protection.
- Battens and sarking: replacing rotten battens or adding sarking and insulation raises materials cost but protects the new roof.
- Gutters and fascia: a new roof often exposes tired gutters that are cheaper to replace at the same time.
- Colour and finish: darker or specialty finishes can change both price and heat load.
Pros and cons of corrugated roof sheets
| Pros | Cons |
|---|---|
| Light, so frames and footings can be simpler than for tiles | Louder in heavy rain unless you add sarking or insulation |
| Fast to install, so the house is exposed for less time | Cheap fixings rust and loosen long before the sheets do |
| Wide range of Colorbond colours and profiles | Dark colours absorb more heat on west-facing roofs |
| Sheds water quickly and handles low pitches well | Cut edges and scratches need prompt treatment in coastal areas |
| Recyclable steel and easy to replace by section | Mixing metals can cause corrosion where they touch |
How to choose corrugated roof sheets
- Decide the job first: full re-roof, patio cover, shed or skylight strip, because the material changes with the use.
- Match the profile to the existing roof if you are extending, since Custom Orb and Trimdek do not blend.
- Pick the coating for your location: coastal Sydney suburbs need a coating suited to salt air, so ask the supplier for its coastal guidance.
- Choose a colour for the aspect: lighter shades reduce heat on west-facing roofs and darker ones suit heritage streetscapes.
- Check council and heritage rules, because some conservation areas control roof colour and profile.
- Compare itemised quotes for the same sheets, fixings, flashings, gutters and disposal.
Installing corrugated roof sheets: rules that prevent leaks
Steel manufacturers publish their own laps, fixings and spans, so always follow the current data sheet for your profile. The verified figures below are from the Laserlite installation brochure and apply to polycarbonate corrugated sheets only.
| Rule (polycarbonate corrugated) | Value |
|---|---|
| Minimum pitch | 5° (about 88 mm fall per metre) |
| Maximum purlin spacing | 800 mm end span, 1000 mm mid span |
| Side lap | 1.5 corrugations |
| End lap | 150 mm on steeper pitches, 200 mm on shallow pitches |
| Overhang into gutter | 50 mm |
| Fixings | About 7 per lineal metre, every 2nd crest on end purlins and every 3rd on mid purlins |
- Check the frame: probe battens and purlins for rot and straighten them before any sheet goes down.
- Fix through the crest with the correct sealing washers so water runs away from every hole.
- Tighten only until the sheet stops rattling, because over-tightening dimples the sheet and cracks plastic.
- Use the maker’s fixings, since Laserlite’s lifetime warranty is voided if non-Laserlite fixings are used.
- Keep dissimilar metals apart, as copper or lead runoff and some timber treatments can corrode steel.
- Work with edge protection and fall arrest, because roofing falls are among the most serious injuries in the trade.
Corrugated roof anchor and safe access
- Fit roof anchors during the re-roof, so future gutter and solar work has certified tie-on points rather than improvised ones.
- Use anchors designed for corrugated profiles, because a standard anchor on the wrong profile can leak or pull out.
- Have the anchors installed and certified by a qualified installer, who will tag them and issue the paperwork for later inspections.
- Never walk on plastic or fragile sheets; use stepping boards across at least two purlins instead.
- Keep ladders and tools clear of the edge and wear a harness on any roof that is wet, mossy or steep.
- Book a licensed roofer for any work above single-storey height rather than doing it yourself.
Plastic, PVC and polycarbonate corrugated roof sheets
Plastic roofing sheets and PVC roof panels are the light-filled option for patios, carports and skylight strips. PVC is the cheapest, polycarbonate is the toughest, and both need correct pitch and spans to stay watertight.
- Polycarbonate: Laserlite 3000 clear passes 93% of light, while platinum passes 18% and cuts 69% of the heat.
- Colour for heat: frost blocks 63% of heat and cream 62%, which is usually what a west-facing patio needs.
- PVC roofing sheets: they cost less but can yellow or become brittle, so avoid them over seating areas.
- Warranty: Laserlite 2000 and 3000 carry a Lifetime Platinum Warranty, and non-Laserlite fixings void it.
- Heaters: keep patio heaters at least 1 m from polycarbonate sheeting.
- Walking: use stepping boards and never stand directly on the sheets.
Our polycarbonate sheet guide goes deeper on colours and costs.
Insulated corrugated roofing and Zincalume vs Colorbond
- Insulated corrugated roofing sandwiches a foam core between steel skins, so it cuts heat and rain noise on patios and extensions.
- Insulated panels cost more than single skin sheets, so compare them with sarking plus batts on a house roof.
- Zincalume has a bare metallic finish that suits sheds, while Colorbond adds a baked-on colour coat.
- Coastal homes should ask the supplier about the coating’s performance near salt air before choosing either.
- Cut edges should be treated promptly so they do not rust back under the paint.
- Warranty terms differ between coatings, so read them before you decide.
See insulated roof panels and the Zincalume vs Colorbond comparison for the detail.
Corrugated roof sheets vs Trimdek
- Look: corrugated has a continuous wave, while Trimdek has flat pans and bold ribs.
- Spans: trapezoidal profiles like Trimdek often cover wider purlin spacing than corrugated, depending on thickness.
- Walkability: the flat pans on Trimdek make working on the roof a little easier.
- Heritage fit: Custom Orb suits older Federation and weatherboard homes better.
- Modern fit: Trimdek reads cleaner on contemporary skillion roofs.
- Price: the two are close, so choose on look, span and installer experience.
Our Trimdek roof sheeting guide covers the profile in full.
Maintaining corrugated roof sheets
- Hose off leaves and dirt a couple of times a year, because trapped debris holds moisture on the surface.
- Clear gutters regularly so water does not back up under the first sheet.
- Check fixings yearly and replace any that are rusted or loose.
- Touch up scratches with the manufacturer’s recommended paint before rust spreads.
- Trim overhanging branches that scrape the surface or drop sap.
- Test old corro for asbestos before any drilling, cutting or pressure washing, and use a licensed removalist if it is positive.
Corrugated roof sheets FAQs
How much do corrugated roof sheets cost per metre?
Steel corrugated roof sheets usually cost about $15–$40 per lineal metre depending on coating and brand (indicative — get itemised quotes). Colorbond sits at the higher end. Installed prices are higher because you also pay for battens, flashings, labour and removal of the old roof, so always compare itemised quotes.
What is the difference between Custom Orb and corrugated iron?
Custom Orb is a specific rounded corrugated profile made by Lysaght, while corrugated iron is the general old name for any wavy galvanised sheet. Today most Custom Orb is Colorbond or Zincalume steel, so the two overlap. What matters is the profile, coating and thickness on your quote.
What pitch do corrugated roof sheets need?
Steel manufacturers publish their own minimum pitch for each profile, so check the current data sheet. For corrugated polycarbonate the minimum is 5 degrees, about 88 mm of fall per metre. Flatter roofs can pool water at the laps and leak, so a different system is needed.
Can you put corrugated sheets over an existing roof?
Sometimes, but only after the frame and old sheets have been inspected and tested for asbestos. Overlaying can trap moisture and add load, so most Sydney roofers prefer to strip and re-sheet. A licensed roofer can confirm what the structure will carry before you commit.
Are plastic corrugated roof sheets any good?
Good polycarbonate sheets with a proper UV layer last many years and suit patios and carports. Cheap PVC can yellow and turn brittle sooner. Match the sheet to the use, fix it with the maker’s fixings and keep the pitch at 5 degrees or more so it stays watertight.
Is Colorbond better than Zincalume for corrugated roofs?
Colorbond adds a painted finish and wider colour choice, while Zincalume is a bare metallic finish that suits sheds and budget roofs. Neither is universally better. Coastal homes should ask the supplier about the coating’s suitability near salt air, then compare the warranty terms before choosing.
Getting corrugated roof sheets installed in Sydney
A corrugated roof is only as good as its frame, laps and fixings. TQN Construct’s licensed roofers replace and re-sheet houses, patios and sheds across Sydney, with itemised quotes and a workmanship warranty. Book a free measure and quote.
