Does Polycarbonate Block UV? Everything You Need to Know (2026)
If you're shopping for polycarbonate sheets in Canada, UV protection is probably one of your top questions — and for good reason.
Quick Answer
Yes — but with an important nuance. Raw polycarbonate on its own actually transmits UV radiation quite well, which makes it vulnerable to long-term sun damage. That's why quality polycarbonate sheets are manufactured with a co-extruded UV-protective coating bonded directly to one or both sides of the panel.
At Plastics Canada, all of our polycarbonate sheets come with this UV protection built in — not applied as an aftermarket film that can peel or wear off.
Is Polycarbonate UV Resistant?
Yes — when it's the right grade of polycarbonate, it's one of the most UV-resistant glazing materials available.
A UV-coated polycarbonate sheet will block up to 99% of UV-B rays, which are the most damaging both to human skin and to the material itself. This makes it a popular choice over standard acrylic or glass in applications where long-term outdoor exposure is unavoidable.
How Polycarbonate Compares
| Material | UV Blocking | Yellowing Resistance | Impact Resistance |
|---|---|---|---|
| UV-coated polycarbonate | Up to 99% | Excellent | 250x stronger than glass |
| Standard acrylic | Moderate | Good | Moderate |
| Tempered glass | Low | N/A | Low |
| Uncoated polycarbonate | Low | Poor | 250x stronger than glass |
The key phrase is "UV-coated." If you're purchasing polycarbonate sheets from a supplier and UV protection isn't explicitly mentioned, ask. Uncoated polycarbonate will yellow and become brittle within a few years of outdoor use.
How Long Does Polycarbonate Last in the Sun?
With proper UV coating, you can expect quality polycarbonate panels to last anywhere from 10 to 25 years outdoors in Canadian conditions — including the freeze-thaw cycles, heavy snow loads, and intense summer UV that our climate demands.
Several factors affect exactly where on that range your installation lands:
- UV coating quality. This is the biggest factor. Co-extruded UV coatings (built into the sheet during manufacturing) outlast surface-applied coatings significantly. Our sheets use co-extruded protection.
- Panel thickness. Thicker panels — 6mm, 8mm, 10mm multiwall — generally hold up longer than thin single-wall sheets because they're more resistant to micro-cracking.
- Installation. Polycarbonate needs room to expand and contract with temperature changes. Improper installation that restricts thermal movement can cause stress fractures.
- Climate and orientation. South-facing installations in sunny regions receive significantly more UV load than north-facing ones.
- Maintenance. A gentle clean with soap and water once or twice a year — and avoiding abrasive cleaners — will meaningfully extend the panel's lifespan.
Signs Your Polycarbonate Is UV Degrading
Even with quality sheets, it's worth knowing what to look for:
- Yellowing or browning — the most visible sign, caused by photooxidation of the polymer
- Hazing or loss of clarity — light transmission drops as the surface degrades
- Brittleness or surface cracking — the sheet becomes less impact-resistant over time
- Chalking — a powdery residue on the surface indicating coating breakdown
If you're seeing any of these on existing panels, it's usually more cost-effective to replace than to try to restore — especially since replacement panels will come with a fresh UV coating and a new performance lifespan.
Choosing the Right Polycarbonate for Your Project
Not all polycarbonate is the same. Here's a quick guide based on common Canadian applications:
Greenhouses and Growing Enclosures
Multiwall polycarbonate (twin-wall or triple-wall) with UV protection on both sides. The air gap provides insulation; the UV coating protects your plants from UV-B while still passing the full-spectrum light they need.
Patio Covers and Pergola Roofing
Solid or multiwall panels, typically 6mm–10mm. UV protection on the top face is essential; double-sided coating is a bonus for longevity.
Skylights and Roof Glazing
Thicker solid or multiwall panels with high UV blocking. Consider tinted options if glare or heat gain is a concern.
Signage and Displays
Solid clear or coloured polycarbonate. UV resistance matters more for outdoor signage than indoor.
Ready to Order Polycarbonate Sheets in Canada?
Whether you're replacing degraded panels or starting a new build, we carry UV-protected polycarbonate sheets in a full range of thicknesses, sizes, and profiles — cut to size and shipped across Canada.