Greenhouse Glazing: Polycarbonate and Plexiglass vs. Glass
One of the most important decisions you'll make when choosing your dream greenhouse is what type of glazing to use. While glass has traditionally been the go-to material for greenhouses, polycarbonate and plexiglass offer some compelling advantages, especially when it comes to durability and weight. Let's take a look at how these materials stack up, with a focus on what makes polycarbonate and plexiglass shine in greenhouse applications.
Glass: The Traditional Choice
Glass has been the standard for greenhouse glazing for centuries, and for good reason. It offers excellent light transmission, allowing the maximum amount of sunlight to reach your plants 1. Glass is also relatively inexpensive and readily available 2. However, glass has some significant drawbacks when it comes to greenhouses:
Fragility: Glass is prone to breaking, whether from hail, falling branches, or errant baseballs. Broken glass not only requires costly repairs but also poses a safety hazard to you and your plants 3.
Weight: Glass is heavy, which can increase the cost and complexity of your greenhouse structure, as you'll need more robust framing to support it 3.
Poor Insulation: Glass doesn't offer much in the way of insulation, meaning your greenhouse can lose heat quickly in the winter and overheat in the summer 1.
Polycarbonate: Insulated Technology
Polycarbonate is a tough, virtually unbreakable plastic that has become increasingly popular for greenhouse glazing. Here's why it excels in this application:
Impact Resistance: Polycarbonate is incredibly strong and can withstand impacts that would shatter glass. This makes it ideal for areas with harsh weather or where there's a risk of accidental damage 3.
Superior Insulation: Polycarbonate provides better insulation than glass, helping to keep your greenhouse warm in the winter and cool in the summer. This can save you money on heating and cooling costs 1. In fact, polycarbonate is so effective at insulating that it can even reduce the cost of running heating and ventilation systems 1.
UV Protection: Polycarbonate blocks harmful UV radiation, which can damage plants and cause fading 1.
Light Diffusion: Polycarbonate diffuses light more evenly than glass, reducing harsh shadows and ensuring your plants receive consistent illumination 1.
Soft Light: Unlike glass, polycarbonate allows soft light to filter through, preventing burning or scorching of plants and creating a more gentle growing environment 4.
Amplified Greenhouse Effect: The insulating properties of polycarbonate actually amplify the greenhouse effect, much like they do in pool enclosures where they can help maintain comfortable swimming temperatures even in winter 6. This means polycarbonate can help you maintain optimal temperatures for your plants year-round.
Plexiglass: Clear Acrylic
Plexiglass, also known as acrylic, is another excellent option for greenhouse glazing. It shares many of the advantages of polycarbonate, including:
Shatter Resistance: While not as impact-resistant as polycarbonate, plexiglass is still much stronger than glass and less likely to break -8. Its durability and shatter resistance have even made it a popular choice for commercial architectural windows -10.
UV Resistance: Plexiglass offers inherent UV resistance, protecting your plants from harmful rays -11.
Clarity: Plexiglass boasts exceptional clarity, allowing for maximum light transmission, similar to glass -11.
Lightweight: Plexiglass is significantly lighter than glass, making it easier to handle and less demanding on your greenhouse structure 2. In fact, it weighs less than half of what a glass sheet of the same size would weigh -13.
Common Applications
While this article focuses on greenhouse glazing, it's worth noting the broader applications of these versatile materials.
Glass is widely used in windows, doors, mirrors, and a variety of household and building applications.
Polycarbonate, thanks to its strength and durability, is used in a wide range of applications, including:
Bullet-resistant windows and security glazing -16
Construction and building materials -16
Protective gear like helmets and face shields 16
Medical devices -17
Automotive components -18
Plexiglass is also used in various applications, such as:
Recreational vehicle windows and sunroofs -16
Skylights and exterior windows -16
Retail displays and signage -16
Aquariums and other containers -10
Conclusion
Choosing the right glazing for your greenhouse is a crucial decision that can significantly impact your plants' growth and your overall experience. While glass remains a viable option due to its high light transmission and affordability, polycarbonate and plexiglass offer significant advantages in terms of durability, insulation, and UV protection.
If durability is your top priority and you want a virtually unbreakable greenhouse that can withstand harsh weather, polycarbonate is the way to go. It offers the best impact resistance, insulation, and light diffusion. If you're on a tighter budget but still want better performance than glass, plexiglass is a good alternative. It provides excellent clarity, UV protection, and shatter resistance, although it may be more prone to scratching. By carefully considering your needs, budget, and the specific conditions in your area, you can select the best material to create a thriving environment for your plants.
Check out more information on the glazing that we offer for our greenhouses here!
Works cited
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