Once you have decided on a greenhouse design and building site, it is time to consider how you will cover the greenhouse. Greenhouses used to be made out of glass, but plastic coverings are the modern standard. There are many types of film used as greenhouse coverings but a handful will stand out as common options. Below are the most popular plastics and why cultivators like them. We've also included some that probably shouldn't be.
A Glance at Greenhouse Plastic Options
Colors: Clear, White, Panda Film
Thickness: 4 mil to 12 mil
Woven or Non-woven
Coatings: Anti-condensate, Anti-dust, UV Protection, Infrared
Types of Greenhouse Plastics
Modern greenhouse plastic options are endless and customizable. Soft polyethylene or stiff polycarbonate glazings are commonly used and offer a variety of features such as different types of light filtration and diffusion, and flame resistance. Building codes, climate, and intended crops will play a large role in determining what glazing to use.
Cheaper Options for Short-Term and Seasonal Growing
4 mil and 5 mil poly is inexpensive and very thin
Usually lacks features like anti-condensate coating and anti-dust coating
The lifespan of the plastic is only about one year
best used for greenhouses that do not operate year-round and are located in a mild climate
Most Common Greenhouse Plastics
Infrared additive which reduces heat loss at night
Up to 35% savings on greenhouse heating costs
Anti-condensate additives help prevent moisture accumulation and droplets that encourage pests
Four-year lifespan and inexpensive
Good for mild-moderate climate
Strength, Insulation, and Longevity
UV coating helps retain clarity for light transmission and makes the plastic more durable
Anti-dust additive provides additional help retaining light transmission
Anti-condensate additives help prevent moisture accumulation and droplets that encourage pests
Woven HDPE-core fabric is durable for harsher climates and puncture-resistant
9 mil clear plastics like this are ideal for snow and harsher climates
Greenhouse Plastic Features
When shopping for greenhouse plastics you will see abbreviations for features like "AC," and "UV." The table below will go over what these abbreviations mean and what advantages these greenhouse plastic features offer.
Feature | Function |
Anti-condensate Additives ("AC") |
|
Anti-dust Additive |
|
UV Coating ("UV") |
|
Infrared Coating ("IR") |
|
Light Dispersion Additives |
|
Woven Plastics |
|
When and Where to Use Polycarbonate Panels
In addition to covering your greenhouse with plastic film, you may consider adding polycarbonate panels. It is very expensive to cover an entire greenhouse in polycarbonate. However, they are a great option for durable end walls. 8mm twin-wall polycarbonate is excellent for heat retention and offers 80% light transmission. The cellular multi-layer structure reduces heating costs in winter while minimizing excessive heat in summer.