4 Types of Greenhouse Plastic to Use

A greenhouse in a sun-light yard
What You'll Need
Polyethylene plastic
Copolymer plastic
Polyvinyl plastic
Polycarbonate plastic
What You'll Need
Polyethylene plastic
Copolymer plastic
Polyvinyl plastic
Polycarbonate plastic

There are myriad benefits to using plastic for building your own greenhouse. They are very easy to build and cost much less than a large glass frame. The plastic is what is going to maintain the heat and humidity in the greenhouse. Depending on the type of plastic that is being used, you can grow a wide variety of flowers even when the winter weather sets in.

What Is Greenhouse Plastic?

Greenhouse plastic is made to be more durable than regular plastic. Regular plastic sheets will tear easily when cut because the ends fray, but greenhouse plastic is specially made to resist tearing and stand up to weather. It is actually knitted instead of just formed into sheets.

This type of plastic is perfect for wrapping around different sizes and shapes of greenhouse structures, and can be framed around vents, doors, and windows.

Types of Greenhouse Plastic

Greenhouses are mostly made out of four different types of plastic. These plastics will generally all last about two to three years before they need to be replaced. Of course, this does not take into account extreme weather such as hurricanes, tornadoes, hail, and severe icing.

Polyethylene Plastic

The first type of greenhouse plastic is called polyethylene plastic. This type of plastic is also available in two different strengths: commercial grade for large industrial applications and a utility grade for personal use. Most home centers will carry the utility grade. Polyethylene plastic will last for a year or two when kept in good condition, and smaller tears can be repaired with a poly repair kit.

Copolymer Plastic

A grade above the polyethylene plastics, this is a little more durable and longer lasting—it can last on your greenhouse upwards of three years before it begins to turn brittle and break. The freezing and thawing of the plastic will cause it to be brittle after a few years. There are also more expensive copolymer plastics that are even more durable and will mimic the effects of glass.

Polyvinyl Plastic

This is a more expensive type of plastic compared to the other two, however, it is even more durable than the previous two. Greenhouses covered over in polyvinyl plastic will benefit from the strength of this plastic. Replacement does not have to happen until after five years if you have taken good care of it with regular cleaning and inspection.

Polycarbonate Plastic

The most durable of all the greenhouse plastic is called polycarbonate plastic. It is actually a double, or a twin wall, polyethylene plastic. It can last for up to a decade if cared for correctly. It will also maintain a lot of heat and humidity for year-round growing.

If you are building, or thinking of building, a greenhouse, look into these greenhouse plastics for an inexpensive and easy do-it-yourself greenhouse option.

Types of Greenhouse Plastic to Use FAQ

What type of plastic is best for greenhouses?

Polyethylene plastic is probably the most commonly used in plastic greenhouses. This plastic is highly flexible and durable, and comes in a big range of thicknesses.

Polyethylene plastic is easy to work with and abundant, so it is not difficult to find and use this plastic to create a greenhouse.

What is the best thickness of plastic for a greenhouse?

Plastic sheeting for greenhouses can be made in a huge range of thickness sizes, but six to 10 mil is the most common range. Thicker plastic lets less light through to the plants.

Is white or clear plastic better for greenhouses?

Greenhouse plastic is most commonly used in three different colors: clear, opaque, and white. Clear plastic lets in the most light, while white and opaque fill the greenhouse with diffused light to promote balanced plant growth.

What is the difference between polycarbonate and acrylic for greenhouse?

Both acrylic and polycarbonate are among the common materials used to make greenhouses. Acrylic is more affordable, if you're looking for the most cost-effective option.

Polycarbonate is slightly more durable than acrylic and withstands both heat and UV rays somewhat better than acrylic.

Do polycarbonate greenhouses stay warm in winter?

Polycarbonate greenhouses do tend to stay warmer during winter than glass greenhouses, but greenhouses are not insulated and will become very cold in winter unless they are heated. Electric fan heaters are a common heating solution for greenhouses in the winter.