Polycarbonate Sheets vs Glass: Understanding Impact Resistance, Benefits and Applications

Polycarbonate Sheets vs Glass: Understanding Impact Resistance, Benefits and Applications

When you're choosing a clear sheet material, strength is often just as important as appearance. Whether you're replacing a skylight, installing machine guards, building a greenhouse or designing retail displays, selecting the right material can save time, money and future maintenance. In South Africa, materials also need to tolerate harsh UV exposure, hailstorms, accidental impacts and demanding industrial environments. That's one of the reasons polycarbonate sheets have become such a popular alternative to traditional glass. Polycarbonate offers exceptional impact resistance while remaining lightweight, easy to fabricate and highly transparent. Compared with ordinary annealed glass, which can break into sharp fragments, polycarbonate is far less likely to break under sudden impact. In this guide, we explain the claim that polycarbonate offers "250 times the impact resistance of glass", compare polycarbonate with glass, review common applications, and help you choose the right type of sheet for your project.

Should You Choose Polycarbonate or Glass?

Before exploring the technical details, here's a simple way to decide. Choose polycarbonate if your project needs:

• High impact resistance
• Reduced risk of injury from broken glazing when correctly specified
• A lightweight material that's easier to install
• UV-protected outdoor performance
• Easy cutting, drilling or cold bending
• Reduced risk of breakage

Glass may still be the better option where scratch resistance or particular optical and decorative requirements are the priority. Standard uncoated polycarbonate scratches more readily than glass or acrylic, although specialist abrasion-resistant grades are available. For many industrial, commercial and architectural applications, polycarbonate offers useful benefits when correctly specified.

Understanding the 250 Times Impact Resistance Comparison

One of the biggest reasons people choose polycarbonate is its outstanding impact resistance. POLYVANTIS states that LEXAN™ EXELL™-D solid polycarbonate sheet has 250 times the impact resistance of glass. This is a manufacturer comparison for that product, rather than a universal rating for every solid, multiwall or corrugated polycarbonate sheet. The comparison concerns impact resistance. It does not mean that polycarbonate is 250 times stiffer, more scratch resistant or able to carry 250 times the load. Actual impact performance depends on the sheet grade, thickness, test conditions and installation. Polycarbonate can flex or deform and absorb impact energy. When correctly specified, it can reduce the risk of breakage-related injury compared with ordinary annealed glass. For applications such as machine guards, safety barriers, skylights and public-facing glazing, the complete installation must be specified for the anticipated impacts, loads and relevant safety requirements.

Why Polycarbonate Performs Differently from Glass

Although both materials can be transparent, they behave very differently under load. Ordinary annealed glass is rigid and brittle and can break into sharp shards. Toughened glass breaks into smaller pieces, while laminated glass generally retains broken fragments on its interlayer. These safety glass products should be distinguished from ordinary annealed glass when comparing breakage behaviour. Polycarbonate is a thermoplastic that can absorb substantial impact energy through deformation. It can still crack, break or become dislodged if its limits or those of the installation are exceeded. This unique combination of strength and flexibility is why polycarbonate is widely used in applications where ordinary glass would be vulnerable to accidental damage. For businesses and homeowners, correctly specified polycarbonate can help reduce accidental breakages and associated replacement costs. Performance in hail, storms and industrial environments depends on the product and installation.

Polycarbonate vs Glass: A Quick Comparison

Property	Polycarbonate	Glass
Impact Resistance	High impact resistance; manufacturer states 250 times that of glass for LEXAN™ EXELL™-D	Varies with glass type; annealed, toughened and laminated glass behave differently
Safety	Can flex and absorb impact; safety depends on specification and installation	Annealed glass can form sharp shards; toughened glass forms smaller pieces; laminated glass retains fragments
Weight	Solid sheet is approximately 50% lighter at equal area and thickness	Greater weight at equal area and thickness
Light Transmission	Up to 90% for some clear products; varies with grade, thickness, colour and construction	Excellent optical clarity
Fabrication	Cutting, drilling and forming options depend on the grade and processing guidance	Requires specialised processing
Outdoor Performance	Use a UV-protected grade specified for outdoor exposure	Generally UV stable; performance depends on the glazing system
Typical Applications	Roofing, skylights, machine guards, signage, protective screens	Windows, doors, decorative glazing

For many South African projects, the decision boils down to balancing durability, safety and ease of installation. Where impact resistance is a priority, polycarbonate is often the more logical choice.

The Benefits of Polycarbonate Sheets

Polycarbonate combines high impact resistance, low weight and versatility, making suitable grades useful for a wide range of commercial, industrial and residential projects across South Africa. Here's why so many architects, contractors and fabricators choose polycarbonate sheets.

Exceptional Impact Resistance for Greater Safety

A key advantage of polycarbonate is its high resistance to impact, although it is not unbreakable. Suitable polycarbonate grades can resist impacts from hail, accidental knocks and other hazards. The level of protection depends on the sheet and its support system, so the product must be selected for the intended application. You'll commonly find polycarbonate used in:

• Machine guards
• Safety barriers
• Protective screens
• Warehouse partitions
• Schools and public buildings
• Bus shelters
• Sports facilities

Where the selected system reduces breakages, businesses may benefit from fewer replacement panels, less downtime and reduced risk of breakage-related injury.

Low Weight and High Impact Resistance

Solid polycarbonate weighs approximately 50% less than glass of equal area and thickness. Equal thickness does not mean equivalent structural performance. The lower weight can offer several practical advantages:

• Easier transportation
• Potentially easier installation
• Reduced structural loading
• Potential savings on handling and installation
• Simpler handling on-site

For larger roofing projects, such as skylights and canopies, reducing weight can make both installation and the supporting framework more efficient.

Excellent Optical Clarity

Strength doesn't mean sacrificing visibility. Some clear polycarbonate products transmit up to 90% of visible light. Light transmission varies with the grade, thickness, colour and sheet construction, so check the data for the selected product. Typical uses include:

• Skylights
• Roof glazing
• Greenhouses
• Protective machine viewing panels
• Retail displays
• Signage
• Public information boards

The result is a material that offers the appearance of glass while providing significantly greater impact resistance.

Built for South African Weather Conditions

South Africa's climate provides unique challenges for building materials. Strong UV radiation, hailstorms, temperature fluctuations and heavy summer rains can quickly damage unsuitable materials. For outdoor applications, always choose UV-protected polycarbonate sheets. Premium products such as LEXAN™ EXELL™-D feature UV protection on both sides, helping the material maintain its clarity and resist yellowing over time. This makes polycarbonate a popular choice for:

• Verandas
• Carports
• Covered walkways
• Patio roofing
• Shopping centre canopies
• Industrial rooflights

Selecting an appropriate UV-protected grade and following its installation and maintenance instructions helps preserve outdoor performance. Any warranty remains subject to the terms for the specific product.

Easy to Cut, Drill and Form

Many polycarbonate grades can be fabricated using suitable standard workshop tools and the manufacturer's recommended techniques. Depending on the grade, fabrication options include:

• Cut to size
• Drilled
• Routed
• Machined
• Cold bent
• Thermoformed

Fabrication methods must suit the selected grade. Some hard-coated sheets are unsuitable for cold bending or thermoforming, so always check the manufacturer's processing guidance. Cold bending can be useful for gentle curves in barrel vaults, canopies and arched walkways. Follow the manufacturer's minimum bend radius for the specific grade and thickness.

Potential Savings Over the Life of an Installation

Although material cost is always important, the overall lifetime cost of an installation often matters even more. Because polycarbonate is less likely to break, projects may benefit from:

• Fewer replacement panels
• Reduced maintenance
• Less downtime in industrial environments
• Lower labour costs for repairs
• Reduced risk of premature outdoor deterioration when an appropriate UV-protected grade is used

Potential lifetime savings depend on the application, maintenance needs and comparison material. Assess the complete installed cost and expected service conditions rather than assuming polycarbonate will always cost less over time.

Where Polycarbonate Sheets Are Commonly Used in South Africa

Thanks to its versatility, polycarbonate is used across numerous industries throughout South Africa.

Industrial Machine Guards and Safety Screens

Appropriately specified polycarbonate is used in machine guards and safety screens to provide visibility and resistance to impact. Applications can include:

• CNC machine guards
• Production line barriers
• Inspection panels
• Safety enclosures

For machine guarding, assess the expected impact, panel size, thickness, support and fixing system. Confirm compatibility with coolants, cleaning agents and other chemicals, and follow the machine manufacturer's requirements. Standard polycarbonate is not automatically suitable as a laser safety window; laser protection requires a specialist product verified for the specific laser and exposure conditions.

Roofing, Skylights and Canopies

Appropriate outdoor polycarbonate grades combine high light transmission with impact resistance and UV protection, making them useful for architectural glazing and roofing. Common applications include:

• Factory rooflights
• Warehouse skylights
• Patio roofing
• Shopping centre canopies
• Walkways
• Carports
• Verandas

Solid polycarbonate is lighter than glass of equal area and thickness. The complete roofing system still requires appropriate design for support spacing, deflection, wind loads, fixings and thermal movement.

Agricultural and Greenhouse Applications

Polycarbonate is also a popular choice in the agricultural sector. Multiwall polycarbonate sheets combine daylight transmission with thermal insulation, making suitable grades useful for:

• Greenhouses
• Nursery tunnels
• Garden centres
• Agricultural buildings

Their internal air spaces help reduce heat transfer. Greenhouse temperature also depends on ventilation, shading, solar gain and the overall design.

Retail Displays and Signage

For retailers and advertisers, durability is just as important as appearance. Polycarbonate performs well in busy locations where accidental impacts are common. Typical uses include:

• Illuminated signs
• Point-of-sale displays
• Menu boards
• Display cabinets
• Protective screens
• Information kiosks

With UV-protected grades, outdoor signage also maintains its clarity for longer.

Security and Protective Glazing

Because of its outstanding impact resistance, polycarbonate is frequently specified where additional protection is required. Applications include:

• Protective glazing
• Security screens
• Public transport shelters
• Reception screens
• Warehouse viewing panels

For security glazing, specify the sheet and complete framing system for the required protection level. High impact resistance alone does not establish a particular security or ballistic rating.

Choosing the Right Polycarbonate Sheet

Not all polycarbonate sheets are designed for the same application. Choosing the right product depends on where it will be used, how much impact resistance is required and whether it will be installed indoors or outdoors.

Solid Polycarbonate Sheets

Clear solid polycarbonate provides an unobstructed view without the internal ribs of multiwall sheet. It offers high impact resistance and lower weight than glass of equal area and thickness. Solid sheets are commonly used for:

• Machine guards
• Safety glazing
• Protective screens
• Retail displays
• Shopfronts
• Architectural glazing

If you need a clear alternative to glass with high impact resistance, consider a solid polycarbonate grade suited to the application, including any UV, abrasion or chemical resistance requirements.

Corrugated Polycarbonate Sheets (non-standard stock item)

Corrugated polycarbonate is designed specifically for roofing applications where strength and weather resistance are important. Typical uses include:

• Carports
• Patio roofs
• Warehouse roofing
• Industrial buildings
• Pergolas
• Covered parking areas

These sheets are lightweight and suitable for a variety of roofing projects when the selected grade and installation system meet the site's weather and loading requirements.

How to Choose the Right Thickness

Selecting the correct thickness is just as important as choosing the right type of sheet. The ideal thickness depends on numerous factors, including:

• The size of the panel
• Support spacing
• Wind loading
• Possible impact
• Intended application

For example, a small machine guard requires different specifications from a large rooflight or greenhouse roof. A sheet that is too thin or inadequately supported may deflect excessively or fail. A thicker sheet alone does not guarantee a suitable installation, so use the manufacturer's design guidance for the complete system. If you're unsure which thickness is right for your application, it's always best to seek technical advice before purchasing.

Tips for Outdoor Installations

South Africa's climate can be harsh on building materials, particularly those exposed to direct sunlight. For the best long-term performance:

• Choose UV-protected polycarbonate sheets.
• For sheets protected on one side, face the UV-protected surface towards the sunlight, as identified by the manufacturer. Follow the product markings and installation instructions.
• Allow for thermal expansion during installation.
• Use manufacturer-approved or confirmed-compatible glazing accessories, sealants and fasteners.
• Clean with mild soap and water using a soft cloth or sponge, then rinse thoroughly. Follow the product's cleaning guidance and avoid abrasive or incompatible cleaners.

Following the manufacturer's installation recommendations will help maximise the material's lifespan and appearance.

Frequently Asked Questions

Is polycarbonate stronger than glass?

Polycarbonate generally offers much higher impact resistance than ordinary annealed glass. This is different from stiffness, scratch resistance or load-bearing capacity. Safety depends on the selected grade and complete installation, and toughened and laminated safety glass have different breakage characteristics from annealed glass.

Can polycarbonate withstand hail?

Appropriate polycarbonate roofing products offer high resistance to hail, but they are not guaranteed to withstand every hailstorm. Performance depends on the sheet grade, thickness, condition, installation and impact severity. Check the selected product's test data and any hail warranty conditions.

Does polycarbonate turn yellow in the sun?

Standard polycarbonate can discolour over time if it is not UV-protected. Premium outdoor grades feature UV protection that helps retain clarity and reduces yellowing during prolonged exposure to sunlight.

Is polycarbonate suitable for roofing?

Suitable polycarbonate products are widely used for patio roofs, carports, pergolas, skylights, canopies and industrial rooflights. Select an outdoor grade and installation system designed for the required spans, loads and applicable building requirements.

Can polycarbonate be cut at home?

Yes. Polycarbonate sheets can generally be cut, drilled and machined using standard woodworking tools. Always use the correct blade and follow the manufacturer's recommendations for the best results.

Which is better: polycarbonate or acrylic?

Acrylic offers excellent optical clarity and generally better scratch resistance than standard uncoated polycarbonate. Polycarbonate offers higher impact resistance. The best choice depends on the application, including impact risks, surface wear, outdoor exposure and any safety requirements.

How long do polycarbonate sheets last?

The lifespan depends on the product and application. High-quality, UV-protected polycarbonate sheets, installed correctly, can provide many years of effective performance in South African outdoor conditions.

Are polycarbonate sheets expensive?

Polycarbonate may offer lifetime savings where its low weight and impact resistance reduce handling or replacement costs. The outcome depends on the specific product, installation, maintenance requirements and alternative material being compared.

Why Choose Maizey Plastics?

Whether you're replacing glass, specifying materials for a new development or looking for a durable solution for industrial or commercial applications, choosing the right polycarbonate sheet is essential. Maizey Plastics supplies LEXAN™ EXELL™-D solid flat polycarbonate sheets. Contact our team to confirm the available colours, thicknesses and suitability for your application. With decades of experience supplying high-quality plastic materials to industries across South Africa, our team can help you select the right product, thickness and specification for your application. Need expert advice? Contact the Maizey Plastics team to discuss your project or browse our range of polycarbonate sheet solutions.