Polycarbonate Roofing Sheet
Roof lights, walkway covers and daylighting — where span, load and UV orientation decide the specification.
Roofing is the largest single use of polycarbonate, and the one where specification errors are most expensive — because a roof that leaks or yellows has to be taken off again.
Three decisions drive the whole job: the span between purlins, the local snow and wind load, and which face carries the UV protection. Get those right and polycarbonate roofing lasts decades.
Choosing the construction
| Requirement | Specify |
|---|---|
| Maximum light, short spans | Solid sheet, 3–6 mm |
| Insulation matters (heated space) | Triple-wall or X-structure, 10–16 mm |
| Long spans, light frame | Honeycomb, 10–20 mm |
| Budget covered walkway | Twin-wall, 6–8 mm |
| Hail or impact risk | Solid sheet, 4 mm and above |
The three failures we see most
UV face fitted downwards. The protected side is marked on the film. Installed upside down, the sheet yellows within two or three years.
Ribs running across the slope. Multiwall channels must run down the fall so condensation drains. Across the slope, water sits in the flutes and algae grows.
No allowance for thermal movement. Polycarbonate expands roughly 3 mm per metre over a 50 °C swing. Fixing holes must be oversized and screws must not be tightened down hard, or the sheet buckles in summer and cracks at the fixings.
Typical applications
- Industrial roof lights and daylighting strips
- Covered walkways and link corridors
- Patio, terrace and pergola roofs
- Stadium and grandstand covers
- Agricultural building roof panels
Minimum order and lead time
This grade ships from 100 m² or 1 tonne — a trial pallet, not a full container. Standard sizes and stock colours run in 7–10 days; non-standard thickness or width in 12–18 days; add 3–7 days for CNC cut-to-size work. Quoted in USD on FOB, CIF or DDP terms. Full detail on the MOQ, lead time & shipping page.
Questions buyers ask
What thickness of polycarbonate do I need for a roof?
It is set by purlin spacing and load, not preference. As a guide, 6 mm twin-wall suits purlins around 700 mm apart; 16 mm triple-wall reaches beyond 1500 mm. Send the frame drawing and your local snow load and we will specify it.
How long does polycarbonate roofing last?
UV co-extruded sheet retains ≥ 85% light transmission after ten years and typically serves 15–20 years. Sheet without UV protection, or fitted with the UV face down, can fail in three.
Can you supply sheet cut to my exact roof lengths?
Yes — cutting to length at the factory removes site waste and offcuts entirely. Send the cutting schedule with your enquiry.