A polycarbonate sheet is a lightweight, impact-resistant plastic roofing panel that lets daylight through while keeping rain out. A quality corrugated sheet costs about $20 per lineal metre, and a fully installed polycarbonate patio roof runs about $220–$360 per m² in Australia (indicative — check the manufacturer’s data sheet and get itemised quotes).
Below you’ll find the sheet types, the colours that control heat, real prices, and the installation rules that decide whether your roof lasts or leaks.
Key points
- Corrugated polycarbonate sheets suit most patios and carports; twinwall sheets add insulation for enclosed rooms.
- Colour matters more than brand: clear lets through 93% of light, while heat-reflective tints cut heat by more than 60% (indicative — check the manufacturer’s data sheet and get itemised quotes).
- Installed polycarbonate patio roofs cost about $220–$360 per m², including posts, footings and frame.
- Most leaks come from installation shortcuts: pitch under 5°, wide purlin spacing, wrong fixings or no expansion allowance.
What is a polycarbonate sheet?
Polycarbonate is a tough thermoplastic with far higher impact strength than glass. Roofing-grade sheets carry a UV-protective top layer so they don’t yellow or turn brittle in Australian sun.
| Term | What it means | Why it matters |
|---|---|---|
| Polycarbonate sheet | Rigid clear or tinted plastic roofing panel, sold as Laserlite, Suntuf, Ampelite or Sunlite | Much tougher than acrylic or fibreglass, so it survives hail and impact |
| UV-protected face | Co-extruded top layer that blocks ultraviolet light | Must face up; installed upside down, the sheet yellows and the warranty is void |
| Profile | Shape of the sheet: corrugated, greca, 5 rib, flat or twinwall | Must match the adjoining metal roof and the purlin spacing |
| Light transmission | Percentage of daylight that passes through the sheet | Decides how bright the area underneath and the room behind it will be |
| Heat reduction | How much solar heat a tinted sheet blocks compared with clear | Decides whether a north- or west-facing patio is usable in summer |
| Purlin spacing | Distance between the roof battens the sheets are screwed to | Too wide and sheets sag, crack at fixings and void the warranty |
For a plain-English definition and how it differs from acrylic, see what polycarbonate sheet is.
Types of polycarbonate sheet
| Type | Best for | Strength / insulation | Price band |
|---|---|---|---|
| Corrugated | Patios, pergolas, carports, Custom Orb–style roofs | Good impact strength, no insulation | $ (about $20/lineal metre) (indicative — check the manufacturer’s data sheet and get itemised quotes) |
| Greca | Wider spans and a bolder rib | Stiffer; allows purlins up to 1200 mm mid span | $–$$ |
| 5 rib (Trimdek-style) | Skylight strips in Trimdek or 5-rib metal roofs | Stiff, wide spans | $–$$ |
| Twinwall / multiwall | Enclosed patios, sunrooms, greenhouses | Hollow cells slow heat transfer | $$–$$$ (indicative — get itemised quotes) |
| Flat solid | Awnings, screens, glazing replacement | Very high impact strength | $$–$$$ (indicative) |
- Brand comparison: colour ranges, warranties and fixings for each brand are in our Laserlite roofing guide.
- Insulated option: cell sizes and where twinwall beats corrugated are covered in the twinwall polycarbonate roofing guide.
- Flat sheets: thicknesses, cutting and screen uses are in the polycarbonate panels guide.
Polycarbonate sheet colours by orientation
| Laserlite 3000 colour | Light transmission | Heat reduction |
|---|---|---|
| Clear | 93% | 0% |
| Opal | 49% | 52% |
| Frost | 47% | 63% |
| Cream | 43% | 62% |
| Platinum | 18% | 69% |
| Gun metal | 16% | 66% |
- West-facing patio: choose platinum or gun metal, which cut heat by about two-thirds and stop the afternoon sun turning the area into an oven.
- North-facing patio: choose frost or cream, which still let in more than 40% of the light while blocking over 60% of the heat (indicative — check the manufacturer’s data sheet and get itemised quotes).
- South-facing or shaded yard: choose clear or opal, because a dark tint over an already shady area makes the living room behind it gloomy.
- Roof directly over living-room windows: choose opal or frost to diffuse light, so the room keeps daylight without harsh glare on screens.
- Greenhouse or vegie patch: choose clear at 93% light transmission, and add shade cloth in January and February if plants scorch.
- Skylight strips in a metal roof: choose opal for a soft, even glow rather than a hot bright stripe across the floor.
Polycarbonate sheet prices in Australia
| Item | Typical price (AUD, Oct 2026) | Notes |
|---|---|---|
| Corrugated sheet (Laserlite 3000, 3.6 m) | About $72 per sheet | Roughly $20 per lineal metre (indicative — check the manufacturer’s data sheet and get itemised quotes) |
| Polycarbonate patio roof, supplied and installed | $220–$360 per m² (typical $280) | Includes posts, footings and frame |
| Insulated-panel patio roof (for comparison) | $350–$600 per m² (indicative — check the manufacturer’s data sheet and get itemised quotes) | Cooler and quieter, but less light |
| Re-sheeting a sound existing frame | Well below full patio pricing | Indicative — get itemised quotes |
| Twinwall or flat sheets | Several times corrugated pricing | Indicative — get itemised quotes |
- Colour: heat-reflective tints cost more per sheet than clear or opal, but they’re usually the difference between a used and an unused patio.
- Sheet length: sheets over 6 m need more handling and fixings, but they avoid end laps that can leak (indicative — check the manufacturer’s data sheet and get itemised quotes).
- Access: two-storey work or no side access adds scaffold or edge protection to the quote.
- Removal: old fibreglass or yellowed sheets must be stripped and disposed of, which adds labour and tip fees.
- Frame repairs: rotten timber purlins or rusted brackets must be fixed before new sheets go on.
- Flashings: new barge capping, wall flashing and gutter work add to the materials list.
Polycarbonate sheet for patios and pergolas
- Pitch the frame at 5° or more, which is about 88 mm fall per metre, so rain clears the laps instead of sitting at the fixings.
- Attach to the house with a flyover or wall flashing, never by tucking sheets under the gutter, which overflows into the patio in storms.
- Keep corrugated mid spans to 1000 mm or less; for a wider frame use greca, which allows up to 1200 mm.
- Mix in a few sheets of a cooler tint on west-facing ends, so the seating area stays shaded while the house side keeps its light.
- Mount patio heaters at least 1 m below the sheets to avoid softening or discolouring the polycarbonate.
- Paint timber purlins white or tape them with aluminium tape under clear sheets so hot spots don’t build up where the sheet touches the timber.
Planning a raised roof over an existing house roof? Compare designs in our flyover patio roof guide.
Polycarbonate sheet for carports
- Choose opal or a light tint over cars, because clear sheets bake the paintwork and interior on summer afternoons.
- Use greca or 5 rib on free-standing carports with wider purlin spacing, so the roof stays rigid in wind.
- Fix every second corrugation on each purlin in high-wind areas, as the manufacturer requires for exposed sites.
- Add a gutter on the low side so runoff doesn’t splash back onto the driveway and stain it.
- Allow clearance for car roofs and roof racks, because tall 4WDs often hit low beams on lean-to carports.
- Pick sheet lengths that cover the full slope, avoiding end laps over the car where a slow drip will mark the bonnet.
Kit sizes and designs are compared in our carport kits and designs guide.
Polycarbonate sheet as skylight strips in metal roofs
- Match the profile exactly: corrugated polycarbonate with Custom Orb, and 5 rib with Trimdek roof sheeting.
- Place strips over living zones, not over bedrooms, where early light and rain noise become a nuisance.
- Use opal for diffused light, because clear strips create a hot, bright band across the floor.
- Allow for expansion at both ends: polycarbonate moves far more than steel, so oversized holes are essential.
- Seal with the brand’s approved silicone only, as some general sealants attack polycarbonate.
- Consider a proper skylight for insulated ceilings; see our skylights guide for sizes and costs.
Pros and cons of polycarbonate roofing
| Pros | Cons |
|---|---|
| Natural light keeps the rooms behind the patio bright | Clear sheets trap heat in summer |
| High impact strength handles typical Sydney hail | Louder in heavy rain than insulated panels |
| Light, so frames and footings can be lighter | Scratches if cleaned with abrasives or solvents |
| Individual sheets can be replaced | Moves with temperature and must be fixed correctly |
| UV-protected ranges resist yellowing for many years | Can’t be walked on, so maintenance needs a ladder |
Polycarbonate sheet installation rules
These figures are from the Laserlite installation data. Ignoring them is the main cause of creaking, leaking and cracked sheets.
| Rule | Corrugated | Greca / 5 rib |
|---|---|---|
| Minimum pitch | 5° (88 mm per metre) | 5° |
| Max purlin spacing (end / mid span) | 800 mm / 1000 mm | 900 mm / 1200 mm |
| Side lap | 1.5 corrugations | 1.5 corrugations (greca), 1 rib (5 rib) |
| 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, every 3rd on mid purlins | |
- Check the UV face points up before fixing; the protective side is marked on the film or sheet edge.
- Pre-drill 10 mm holes for sheets up to 4.2 m and 12 mm for longer sheets, unless using the brand’s self-drilling fixings, so each sheet can expand.
- Fix through the crest, never the valley, with sealing washers, so water runs away from every hole.
- Tighten only until the sheet stops rattling; over-tightening dimples the sheet and cracks it within a few summers.
- Work from stepping boards across at least two purlins, never directly on the sheets.
- Use the brand’s own fixings, because Laserlite’s lifetime warranty is void with non-Laserlite fixings.
Unsure whether your frame has enough fall? Use our roof pitch calculator.
Replacing old fibreglass or yellowed polycarbonate sheets
- Inspect the frame first: probe timber purlins for rot and check steel brackets for rust before ordering sheets.
- Measure purlin spacing: if mid spans exceed 1000 mm, corrugated won’t comply, so switch to greca or add purlins.
- Confirm the fall is at least 5°; many older patios were built flatter, and correcting it during re-sheeting costs far less than chasing leaks.
- Order full-length sheets to remove end laps, which are the most common leak point on long patios.
- Replace every fixing and flashing, because re-used screws and perished washers fail early and void the new warranty.
- Test very old sheeting for asbestos before cutting or breaking it; see how to identify asbestos roofing.
Cleaning and maintaining polycarbonate roof sheeting
- Hose the roof every 3–6 months from a ladder, because leaf litter at the laps holds moisture and grows algae (indicative — check the manufacturer’s data sheet and get itemised quotes).
- Wash with mild soapy water and a soft brush; abrasive pads and solvent cleaners scratch and cloud the surface.
- Keep pressure washers well back from the sheet, or skip them, as a close jet can damage the UV layer.
- Check fixings once a year and replace any cracked or perished washers before they leak.
- Clear the gutter end of each sheet, where debris collects at the 50 mm overhang and causes overflow.
- Trim overhanging branches so falling limbs and sap don’t scratch or stain the sheets.
Before you get a polycarbonate sheet quote: checklist
- Patio or carport size in metres (length × width) and which way it faces
- Existing frame material (timber or steel) and its condition
- Current fall, or the height difference between the house end and the low end
- Preferred colour based on orientation (see the colour section above)
- Whether old sheets need removal, and their approximate age
- Access: side access, single or two storey, and any trees over the roof
Polycarbonate sheet FAQs
How long does a polycarbonate sheet roof last?
A UV-protected polycarbonate sheet installed at the right pitch with the correct fixings lasts many years in Sydney conditions. Premium ranges such as Laserlite 2000 and 3000 carry a lifetime warranty when installed with the brand’s own fixings. Cheap sheets without a proper UV layer can yellow and turn brittle within a few years.
Is polycarbonate better than fibreglass roofing?
For most homes, yes. Polycarbonate has much higher impact strength, keeps its clarity longer and is less likely to go brittle. Fibreglass is cheaper upfront but discolours and lets less light through over time. Replacing old fibreglass with polycarbonate is one of the most common patio upgrades in Sydney.
Can you walk on polycarbonate roof sheets?
No. Polycarbonate roof sheets aren’t designed to carry a person between purlins and can crack or deform. Use stepping boards laid across at least two purlins, or work from a ladder at the edge. This protects both you and the warranty.
Does polycarbonate roofing get hot underneath?
Clear sheets can make a patio noticeably hotter because they pass 93% of the light. Heat-reflective colours such as platinum, frost or cream cut heat by more than 60% while still letting some light through, so they suit north- and west-facing areas (indicative — check the manufacturer’s data sheet and get itemised quotes).
What is the minimum pitch for a polycarbonate roof?
The minimum pitch for corrugated polycarbonate is 5 degrees, about 88 mm of fall per metre. Below that, water sits at the end laps and fixing holes, causing leaks, dirt build-up and algae. Flatter roofs need a different roofing system.
Is polycarbonate the same as Perspex?
No. Perspex is a brand of acrylic, which is clearer but more brittle and can crack under impact or when drilled. Polycarbonate is far tougher, which is why it’s the standard for patios and carports in Australia.
Getting polycarbonate roofing installed in Sydney
A polycarbonate sheet roof is only as good as its pitch, purlin spacing and fixings. TQN Construct’s licensed roofers install and re-sheet polycarbonate patios, carports and skylight strips across Sydney with manufacturer-approved fixings, so your warranty stays intact. Book a free measure and quote.
