Too Long; Didn't Read
- Polycarbonate (Lexan) is roughly 250 times stronger than glass and 30 times stronger than acrylic — it stops bullets; acrylic does not.
- Acrylic (Plexiglass) transmits 92% of visible light and stays crystal-clear for decades without UV treatment; polycarbonate yellows unless coated.
- Polycarbonate scratches more easily than acrylic, but you can add a hard coat — you cannot restore yellowed polycarbonate.
- Use polycarbonate where security, impact resistance, or vandal resistance matters. Use acrylic where optical clarity and long-term appearance are the priority.
- Acrylic costs 30–50% less than polycarbonate of the same thickness — the right choice depends on the threat level, not the price tag.
Answer First: Polycarbonate (sold under brand names like Lexan) is the stronger plastic — roughly 30 times stronger than acrylic and 250 times stronger than standard glass. It is used in riot shields, hockey arena boards, and bullet-resistant glazing. Acrylic (sold as Plexiglass, Lucite, and others) is not as tough, but it transmits more light (92% vs. 86–88%), resists UV degradation without coatings, and costs 30–50% less. For security and impact resistance, use polycarbonate. For long-term optical clarity in a lower-risk application, use acrylic.
The question comes up on job sites, in hardware stores, and in homeowner renovation threads more often than you might expect. Someone has a broken garage door light panel. Someone else wants to replace the glass in a basement window with something that won't shatter if a lawn mower throws a rock. A Toronto restaurant owner wants to replace the plate glass in a front window that gets tagged every three months.
Both materials look the same at the hardware store. Both are clear. Both are lighter than glass and won't shatter into sharp shards. But they behave completely differently when you ask them to do real work.
This is the breakdown.
What Are These Materials, Actually?
Acrylic (PMMA — Polymethyl Methacrylate) — the plastic sold as Plexiglass, Lucite, Acrylite, and a dozen other trade names. It is a rigid thermoplastic made from petroleum-derived monomers, first commercialized in the 1930s. If you have ever seen a retail display case, an aquarium wall, or a skylight dome, you have seen acrylic.
Polycarbonate (PC) — sold as Lexan (SABIC), Makrolon (Covestro), and Tuffak, among others. Developed in the 1950s, it is a tougher, more impact-resistant engineering plastic. If you have seen a hockey rink's protective boards, a fighter jet canopy, or a bank teller window, you have seen polycarbonate.
They are both transparent plastics that sub for glass. That is where the similarity ends.
Impact Resistance: This Is Not Close
Polycarbonate: 250× stronger than glass. Acrylic: 10–17× stronger than glass. Polycarbonate vs. acrylic head-to-head: roughly 30× more impact resistant.
This is the defining difference between the two materials. When standardized impact tests are run, polycarbonate absorbs over 100 times more force than acrylic before it fractures.
Acrylic does not bend. It cracks. Hit it hard enough and it fails suddenly, with sharp edges and a loud crack. It is stronger than glass — if someone throws a rock at a standard residential window, acrylic would fare considerably better. But it has a breaking point.
Polycarbonate does not crack cleanly. It deforms, stretches, and absorbs the impact. This is why it is the material behind bullet-resistant glazing. Under UL 752 (the US standard for bullet-resistant materials), a glass-clad polycarbonate panel at Level 1 — roughly 22mm thick — resists three 9mm handgun rounds. Level 8, at nearly 90mm thick, stops multiple rifle shots.
Quotable Nugget: Standard polycarbonate is 250 times more impact-resistant than glass and roughly 30 times more impact-resistant than acrylic of the same thickness — the same material used in riot shields and hockey arena boards.
For the Scarborough convenience store owner who has had his front window smashed twice in a year, or the Etobicoke school with ground-floor glazing in a high-traffic corridor, this difference is the whole conversation. Our commercial security glass installations default to polycarbonate or glass-clad polycarbonate precisely because of this gap.
Optical Clarity: Acrylic Wins, But Not by as Much as You Think
| Property | Acrylic | Polycarbonate |
|---|---|---|
| Light transmittance | 92% | 86–88% |
| Yellowness Index (new) | Very low | Slightly higher |
| UV resistance (uncoated) | Excellent — <3% degradation over 10 years | Poor — yellows without UV coating |
| UV resistance (coated) | Good | Good (UV-coated grades available) |
| Can be polished to restore clarity? | Yes | No |
Acrylic's 92% light transmittance is actually better than standard float glass (around 90%). It genuinely looks like glass. Polycarbonate at 86–88% is still very clear — you are not going to notice the difference in a single panel — but in applications where matched appearance matters, acrylic wins.
The UV story is where this gets important. Uncoated polycarbonate yellows in sunlight. Not immediately. Not in a year. But over 5–10 years outdoors without a UV-protective hard coat, you will notice a warm yellow tint that you cannot polish or sand away. Once polycarbonate yellows, the panel needs to be replaced.
Acrylic does not have this problem. It is inherently resistant to UV degradation. The same panel that goes up on a Toronto south-facing facade in 2026 will look essentially the same in 2036.
UV-coated polycarbonate closes this gap significantly — quality coated grades maintain clarity for 10–15 years outdoors. But the coating matters. If you are sourcing polycarbonate panels and the supplier cannot tell you whether they carry UV protection, assume they do not.
Quotable Nugget: Uncoated polycarbonate yellows under UV exposure and cannot be restored to its original clarity — acrylic, by contrast, shows less than 3% optical degradation after 10 years outdoors and can be polished if it hazes.
Scratch Resistance: The Ironic Reversal
Here is the thing that surprises most people: acrylic scratches less easily than polycarbonate.
It is counterintuitive. The stronger plastic is also the softer one on the surface. Polycarbonate's toughness comes from its ability to flex and deform at the molecular level — the same property that makes it impact-resistant also makes its surface more vulnerable to abrasion.
Practical implications:
- A polycarbonate panel in a high-traffic area (a bus shelter, a school corridor, a retail cash counter) will look scratched and hazy within a few years without a hard coat.
- A hard coat applied at the factory significantly improves scratch resistance on polycarbonate. Specify hard-coated panels for any application where people will be touching or cleaning the surface regularly.
- If an acrylic panel gets scratched, you can polish it back to near-original clarity with automotive polish or plastic-specific compounds.
Neither material is as scratch-resistant as glass. Both will show wear in high-contact applications. The difference is that acrylic's wear is recoverable; polycarbonate's surface wear, without a coating, is not.
How Each Material Handles a Toronto Winter
Toronto's climate is genuinely punishing for exterior materials. We see -25°C wind chill in January and +35°C humidex in July. That 60°C annual swing puts real stress on anything mounted in a frame.
Thermal expansion is the practical concern. Both acrylic and polycarbonate expand and contract with temperature. The coefficient of thermal expansion for both is around 0.000039 per inch per °F — which means an 8-foot panel expands and contracts roughly 12–15mm between the coldest February day and the hottest August day.
This is not theoretical. If panels are cut tight and set into a rigid frame without expansion allowance, they will bow, creak, or crack. Any installer who does not account for this is setting you up for callbacks.
Temperature limits also matter:
- Acrylic softens above 80°C and can be used down to about -35°C.
- Polycarbonate handles up to 130°C and the same lower limit.
For standard Ontario residential applications, both materials survive the temperature range fine. Where polycarbonate earns its extra margin is in applications near heat sources — skylights with concentrated solar gain, panels near rooftop HVAC equipment, or applications where summer solar loading is significant.
Chemical resistance is another practical note. Neither material loves harsh solvents. Polycarbonate handles ammonia-based cleaners (like window sprays) better than acrylic — clean acrylic with mild soap and water and nothing stronger, or you will craze the surface. Polycarbonate tolerates a broader range of cleaning products, which matters in commercial environments where janitorial staff are not reading material data sheets.
The Tensile Strength Paradox
Impact resistance is not the same as tensile strength. This is where the comparison gets genuinely counterintuitive.
Acrylic has higher tensile strength than polycarbonate:
- Acrylic: ~80 MPa
- Polycarbonate: ~60–70 MPa
Acrylic also has higher flexural strength (115 MPa vs. ~90 MPa for polycarbonate).
So acrylic is stiffer and stronger in a static load sense — hang something from it, push it uniformly, and it resists more. But polycarbonate absorbs dynamic impact — sudden, high-energy hits — far better. This is the difference between a material that resists stress and a material that absorbs shock.
Think of it this way: a ceramic plate has higher compressive strength than a rubber sheet. But you would rather drop the rubber sheet.
Quotable Nugget: Acrylic has higher tensile strength than polycarbonate (80 MPa vs. 60–70 MPa), but polycarbonate absorbs dynamic impact roughly 30 times better — making them the right tool for different threat types, not interchangeable substitutes.
Cost: What Are We Actually Talking About?
Acrylic sheet runs roughly $1.50–$2.00 per kilogram at distributor pricing. Polycarbonate runs $2.50–$3.50 per kilogram — approximately 30–50% more for equivalent dimensions.
For a single small panel, the difference is inconsequential. For a commercial project with hundreds of square feet of glazing, it is real money.
The right framing is not "which is cheaper" but "which is cheap enough for this application."
- If you need security glazing for a storefront, the extra cost of polycarbonate is not a discretionary upgrade — it is the only material that makes sense.
- If you need a replacement panel for a greenhouse or a basement hopper light, acrylic does the job for less.
- If the application involves long-term outdoor exposure and you want the panel to still look clean in ten years, acrylic's UV performance shifts the cost calculus in its favor — a polycarbonate panel that needs replacement in seven years because it yellowed costs more over the lifecycle than an acrylic panel that lasts fifteen.
Which One Should You Use? A Decision Framework
Use polycarbonate when:
- Security or vandalism resistance is the goal (storefronts, school windows, transit shelters)
- The application involves high impact risk (garage door light panels, machine guards, hockey boards)
- You need bullet-resistant glazing (UL 752 rated assemblies use glass-clad polycarbonate)
- The application involves significant heat exposure
- You are installing greenhouse panels or sunroom roofing where hail is a real risk
Use acrylic when:
- Long-term optical clarity is the priority (display cases, aquariums, retail interiors)
- The application is primarily decorative or low-risk
- UV exposure is high and you want inherent resistance without relying on a coating
- Budget is constrained and the threat level does not justify polycarbonate
- You need a material you can polish and maintain in the field
Neither is a direct substitute for tempered or laminated glass in standard residential window units. If your goal is replacing a failed insulated glass unit in a vinyl or wood window, the right answer is a new IGU — glass-clad, sealed, with argon and Low-E — not a plastic panel dropped into an old sash. We walk through when that makes sense in our guide to glass-only replacement for broken seals.
[Image Idea: Side-by-side cross-section of an acrylic panel and a polycarbonate panel showing the molecular flex difference under impact, with impact resistance numbers labeled]
Where You Will Actually See These Materials in the GTA
A few real-world contexts where this distinction matters around Toronto:
Schools and transit infrastructure. The TTC, school boards, and the City of Toronto have been specifying polycarbonate for vandalism-prone glazing since the late 1990s. The Scarborough bus shelters that survive year after year of thrown objects are polycarbonate, not glass. Our commercial security glass installations in North York and Scarborough school corridors use similar specifications.
Cannabis retailers and financial services. Since Ontario legalized retail cannabis, transaction windows in dispensaries and similar high-risk retail environments typically require ballistic-rated glazing. Glass-clad polycarbonate at UL 752 Level 1 or Level 2 is the standard. This is a growing category of work in 2026.
Heritage storefronts on Queen West and Kensington. Anti-graffiti film applied to standard glass is effective against spray paint but not against physical smashing. Some operators in high-vandalism stretches are switching to hard-coated polycarbonate panels in aluminum frames — not because they need bullet resistance, but because a smashed polycarbonate panel does not scatter glass across the sidewalk and does not require an emergency board-up call at 2 a.m.
Residential basement windows. A 1960s Etobicoke bungalow with steel hopper windows at grade is a break-in target. Replacing the glass pane with a polycarbonate insert — properly framed with expansion allowance — is a practical, affordable upgrade. It will not stop a determined entry, but it adds meaningful resistance to opportunistic break-ins. For a full look at basement glazing options, our egress and basement window guide covers the code constraints.
Quotable Nugget: For vandalism-prone glazing in Toronto, polycarbonate panels do not scatter broken glass across the sidewalk, eliminating the emergency board-up scenario that typically costs $400–$800 at 2 a.m. on a weekend.
The One Thing People Get Wrong About Polycarbonate
The assumption is that polycarbonate is the obvious upgrade in every situation — stronger is better, full stop.
It is not that simple.
If you install uncoated polycarbonate in a south-facing exterior application, it will yellow. If you install it without proper expansion gaps in a tight aluminum frame, it will bow in summer. If you clean it with an ammonia-based spray, you will scratch it. And if you are paying polycarbonate prices for an application where acrylic would do the job for 40% less, you have optimized the wrong variable.
The right material for the right application. That is the whole framework.
If you are not sure which one applies to your situation — a storefront repair, a basement security upgrade, a school window specification — that is a conversation worth having before the order is placed.
Frequently Asked Questions
Is Lexan the same as polycarbonate?
Lexan is a brand name for polycarbonate plastic, originally developed by GE Plastics (now SABIC). All Lexan is polycarbonate, but not all polycarbonate is Lexan — it is similar to how all Kleenex is tissue but not all tissue is Kleenex.
Can polycarbonate be used as a window replacement in a Toronto home?
Yes, polycarbonate panels can replace glass in basement hopper windows, garage door glazing, and security applications. For standard residential windows, it is not a direct substitute — thermal expansion in Canada's wide temperature swings (-25°C to +35°C) requires proper frame allowances, and it does not seal into a standard IG unit the way glass does.
Does acrylic yellow in the sun?
Standard acrylic is inherently UV-resistant and shows as little as 3% degradation after 10 years of outdoor exposure. Polycarbonate, by contrast, yellows without a UV-protective coating. If long-term outdoor clarity matters, acrylic wins by default.
Which is better for a greenhouse or sunroom panel — acrylic or polycarbonate?
Polycarbonate is the standard choice for greenhouse panels and sunrooms because it can handle hail, snow load, and impact without shattering. Twin-wall polycarbonate also provides insulation value that single-sheet acrylic cannot match.
How thick does polycarbonate need to be to stop a bullet?
At UL 752 Level 1, a glass-clad polycarbonate unit is roughly 22mm (0.855 inches) thick and resists three 9mm handgun shots. Higher levels scale up to 89mm. Standard 6mm polycarbonate sheet used in windows is not bullet-resistant.
Thinking about a security upgrade or a replacement panel for your property? We work with both acrylic and polycarbonate glazing across the GTA — storefront replacements, school specifications, residential security windows. If you want a straight answer on which material makes sense for your situation, we can put together a no-pressure assessment. Contact Installix or reach out through our commercial glass repair service.