Polycarbonate greenhouse panels are a type of clear, plastic panel used to construct greenhouses. Cheaper, lighter, and more durable than glass, they are often used as part of do-it-yourself greenhouse kits and come in pre-cut standardized sizes. They can also be purchased in large sheets and easily cut, as needed, into various shapes. Polycarbonate is similar glass in that it allows light and energy from sunlight to pass through but then traps that energy inside the greenhouse, helping to keep the temperature higher than the surrounding outside environment. Available in a number of colors, styles, thicknesses and finishes, polycarbonate greenhouse panels are one of the most common greenhouse construction materials.
Glass was once the only option for greenhouse coverings. The invention of plastics created much less expensive, more durable, and lighter alternatives, and polycarbonate is one of the most popular. As a whole class of plastics rather than a specific type, polycarbonates can vary from each other, but they tend to be extremely tough and many times stronger than glass while weighing much less. Some clear polycarbonates even provide superior light transmission as compared to glass. Solid panels are also much more durable than the strongest of the plastic film coverings sometimes used in greenhouse construction.
Depending on the desired look or specific application, many types of polycarbonate greenhouse panels are available. They may be clear, translucent or opaque. Opaque panels are not truly opaque to light, but are designed to be impossible to see details through. Translucent panels allow for some perception of detail, but objects appear indistinct and blurry. Panels can also be tinted with color in a way that masks a portion of the light, like sunglasses.
Structurally, polycarbonate greenhouse panels can vary a great deal. They may be simple, flat sheets like panes of glass, and these types of panels are often used when an attractive look or architectural effect is desired. Corrugated panels are common in commercial applications as they have improved strength when compared to a flat panel of identical thickness. Some panels are essentially flat, but ribbed, a design feature that also offers improved strength. Insulated panels may be constructed of two or more thin panels separated by an airspace reinforced with baffles that serve to trap air in addition to providing extra strength.