You basically have three options when picking a side for your greenhouse: glass or plastic (fiberglass, polycarbonate, polyethylene film). Which option is best for your greenhouse will depend on how much insulation it needs and how much you can afford to spend. When choosing siding for your greenhouse, consider the following advantages and disadvantages.
Each material will have its own set of costs, advantages, drawbacks, maintenance requirements, and aesthetic preferences. Not all materials are appropriate for all types of greenhouse construction or all climates.
Learn more about the most typical materials used for greenhouses’ light-transmitting walls and roofs as well as which ones are best for different types of greenhouses in the materials guide below.
Greenhouse Glass Panels
Glass is stunning but has a low heating efficiency (.95 R) and is readily broken. To be useful, it must be twice or triple strength.
Drawbacks of glass:
- Can burn plants and does not diffuse light.
- Because of its weight, a stronger frame, foundation, and smaller, more numerous panes are required.
- Because there are so many seams and panes, it might be drafty.
- The framing must be rigid and precisely square. Installing could need a professional.
The most expensive but typically most resilient material for greenhouse construction is glass. If glass is a suitable material choice for your application and budget, be careful to consider the following factors as you compare various glass panels:
- What Are the Safety Features of This Glass?
- Do I Need Single-Pane or Double-Pane Glass?
- How Difficult Will It Be to Maintain These Glass Panels?
Greenhouse Plastic Panels
Fiberglass, polycarbonate, polyethylene film, and any upcoming improvements are all examples of plastic greenhouse siding. They can all be made in larger panes or sheets since they are all lighter and more flexible than glass, which lowers drafts and facilitates construction.
Although fiberglass is not transparent, it allows almost as much light in as glass greenhouses. The light is diffused, and the fiberglass used in greenhouses has a gel coat applied to it to block UV rays. It offers good insulation and retains heat better than glass. (.83 R) A gardener who only needs a place to start seeds in the early spring can get by with a fiberglass greenhouse, which is a good choice for a starter greenhouse.
Drawback aspect includes:
- After approximately 6 years, UV gel protection burns off and turns yellow.
- It’s challenging to get the shaky ends to merge neatly.
- Less light enters through dirty windows and corrugated surfaces.
Although it is also a corrugated plastic, polycarbonate siding for greenhouses is the toughest and virtually as transparent as glass. Additionally, it lasts up to 2-3 times longer than fiberglass does.
Single, double (1.4 – 1.9 R), and triple (2.5 R) wall thicknesses of polycarbonate are available.
The cheapest and sexiest polycarbonate is single wall polycarbonate. However, compared to its bulkier brothers, it offers less strength, heat retention, and light diffusion.
Triple and double walls Because of the air spaces between the walls, polycarbonate provides even higher insulation. Although they are more expensive, you will spend less on heating. The lifespan of polycarbonate, which is +15 years in most places, is another benefit. Polycarbonate is the finest material to use if you plan to overwinter delicate plants, try to grow veggies throughout winter, and use your greenhouse from fall through spring.
If you’re a gardener who uses your greenhouse primarily for seed beginning, polyethylene film is a simple and affordable alternative. For improved insulation, it comes in sheets that can be utilized in single or double layers. (.85 – 1.4 R) It functions effectively, but it only lasts for a short time—between two and four years, depending on the product and the climate. Commercial farmers prefer it because it is affordable, versatile, and they have a staff to replace it periodically. The ideal configuration for polyethylene film is a double layer with an air space in between.
Poly film has the advantage of being the least priced material option for greenhouses, being simple to work with for a DIY project, and coming in a variety of opacities and thicknesses.
If you determine poly film is the best option for your greenhouse, make sure you have the following questions answered before you make a purchase:
- What’s the Useful Life of the Film?
- Do I Need Woven Poly Film?
- What Film Opacity Do I Need?
- Do I Need Black or White Silage Film?
- Do I Need Condensation Control?
Each material has a unique set of characteristics and design considerations. If extreme environmental problems (hot heat, extremely low temperatures, high winds, enormous hail, etc.) are a concern, then it is worthwhile to learn more about each material in further detail. Not all materials are feasible in all climates or for all forms of greenhouse construction.