Greenhouses vary from large, freestanding structures which could accommodate hundreds of plants into small, window-mounted units which have only enough room for a couple of plants. Different materials are used for the windows or panels of a greenhouse, depending on the design of this greenhouse, the amount of ultraviolet light you want to pass through also any privacy concerns that you might have.
Glass
Glass panels and windows are conventional for greenhouses and offer both permanence and easy maintenance. When properly installed, glass panels are weather tight and retain heat and humidity inside the greenhouse and enable 90 percent of light to pass through. Greenhouse glass is offered in several types, including textured glass panels that are typically stronger than smooth glass. The biggest drawbacks to using glass in a greenhouse is that, depending on the glass used, it might split easily, requires strong support because of its weight and may be expensive to install.
Fiberglass
A lower-cost option to glass, fiberglass panes provide permanence and impact resistance in a lightweight fabric that doesn’t require as durable of a frame to use. Although wood comes in a selection of shades and opacities, only clear, transparent or translucent fiberglass should be used to get a greenhouse to ensure that enough light may pass through. Avoid low-grade fiberglass because it discolors significantly over time, reducing the amount of light your plants get. Resin-coated fiberglass continues for 15 to 20 years on average, though since the leaf is eroded away, the fibers under will soften as they gather dirt and dust. Light penetration is initially the same as glass, through this degrades over time as the fiberglass becomes discolored.
Single-Wall Plastic
Single-wall plastic coverings made of acrylic, polycarbonate or similar materials are stiff plastic panels which may be used similarly to glass or fiberglass. As with fiberglass panels, this plastic may discolor and yellowish over time; acrylic sheeting typically yellows at a slower speed than polycarbonate, though polycarbonate sheeting is usually coated with a UV inhibitor to slow the speed of yellowing. Both acrylic and polycarbonate coverings may be used on curved constructions which would be difficult to cover with glass or fiberglass, with polycarbonate being slightly more flexible than acrylic. Provided that they aren’t yellowed, plastic coverings let as much light through as glass, but might be somewhat expensive.
Double-Wall Plastic
Much like single-wall plastics, double-wall plastic coverings are generally made of polycarbonate or similar materials and feature two stiff plastic walls with a layer of plastic webbing between them to function as insulation. The double layers of material and insulation layer between them assist double-wall plastic coverings to retain heat better than single-wall coverings, though it also calculates their flexibility marginally when installing them on curved surfaces. Both layers of plastic also reduce light transmission marginally, only allowing approximately 80 percent of light through.
Plastic Film
Plastic film coverings have been installed in two layers with a layer of air between them to act as insulation. These coverings are lightweight and affordable, but typically need to be replaced in part or in whole every one to five years, depending on the plastic level used. Light transmission is generally like glass, even though this might fluctuate slightly with plastic level.
Other Materials
Some greenhouse producers make their own proprietary panels to accompany their greenhouse constructions, though these panels are typically variations of fiberglass or plastic designs. The price and durability of these proprietary panels may vary, as can their accessibility and ease of replacement. These materials often focus on providing better insulation and light penetration compared to other options, although the real gains they offer might not be significantly higher compared to non-proprietary materials.