How To Build A Greenhouse Out Of Plastic? (Explained)

How do you build a greenhouse out of plastic? It’s not as hard as it sounds, and it can save you money on groceries. 

If you want to enjoy the benefits of having your own greenhouse in your backyard, read this guide to learn how to make one from start to finish! 

We’ll walk you through all the steps involved with making a DIY plastic greenhouse, including information about where to source materials and what kind of polyethylene is best for the job.

How to Build a High-Tunnel Greenhouse | Ask This Old House
Building a greenhouse out of plastic is an affordable option
Plastic greenhouses provide good insulation
Plastic materials offer durability and versatility
Proper design and ventilation are important for plastic greenhouses
Regular cleaning and maintenance are necessary

Determine What Kind Of Plastic To Use

The first thing you should do is determine what kind of plastic to use. There are many different types of plastic, but here we will only talk about those that have been approved for food packaging. 

The most common type of plastic for greenhouse construction is polyethylene, which comes in various thicknesses and densities. You can choose between opaque or clear, depending on your preference.

The best size will depend on several factors: how much space you have available, what you want to grow in it and how much light-blocking material (such as shade cloth) you plan to use with it. 

If possible, try out different sheets at home before buying them so that you know exactly how big each one needs to be when folded up (it’s always easier if they fit right into their box). For example:

  • If using 6mm thick polyethylene sheeting then each sheet would be around 3′ X 4′.
  • If using 4mm thick polyethylene sheeting then each sheet would be around 2’ X 3’6″.

When it comes to constructing different types of structures, such as a temporary canopy, it’s important to learn from experienced individuals. Our guide on building a temporary canopy – My Experience provides valuable insights and step-by-step instructions to help you create a sturdy and versatile canopy for various occasions.

Learn The Basics Of Greenhouse Construction

First, it’s important to note that there are many different types of greenhouses. The most common type is the lean-to model, which consists of two walls that lean against a wall or structure (like your home) and another wall that extends out to shade plants. 

There are also hoop houses (which are more temporary structures), cold frames (smaller versions of a greenhouse that can be covered with plastic), and even vertical farms where plants are grown indoors using hydroponics or aeroponics. 

All these types can be built using the same basic principles but may require some modifications depending on what you want to do with them!

Greenhouses offer several benefits including: protecting plants from weather extremes; growing food year round in areas where it wouldn’t normally be possible; being able to grow exotic fruits and vegetables without having access to soil; 

being able to protect certain plants from pests because they’re inside versus outside where pests can reach them easier; keeping insects away from vulnerable food sources like honeybees who live inside hives so they don’t get eaten by predators at night when no one’s watching over them constantly…etcetera etcetera!

Choose A Location For The Greenhouse

So you want to build a greenhouse out of plastic. First, you should choose the location for your greenhouse. 

The best place would be somewhere in the sun that has plenty of soil and water. Temperature and humidity are also important factors to consider when choosing where to construct your greenhouse. 

You’ll need enough sunlight and ventilation for the plants inside your structure, so make sure there are windows or vents that allow for airflow and temperature regulation throughout the year. 

Finally, make sure there is plenty of space around your garden so it doesn’t become overcrowded with weeds or other plants growing nearby!

Curious about what crops thrive in a greenhouse during July? Our comprehensive article on what you can grow in a greenhouse in July – Find Out offers an extensive list of plants that flourish in the summer season, allowing you to maximize the potential of your greenhouse all year round.

Decide What Type Of Framework You Want To Use

The last step before you can start building is to decide what type of framework you want to use. There are three common options: wood, metal, or PVC. Each material has different advantages and disadvantages that will help determine your greenhouse design.

Wooden frames are often the most attractive option for traditional-looking greenhouses, but they can be bulky and require more maintenance over time because wood is more likely to warp in humid climates than other materials.

Metal frameworks are sturdy but also heavy and hard to move around once they’re built since they’re made with thick steel bars instead of lightweight aluminum pipes like plastic tubular frames (PVC). 

They’re also prone to rusting if exposed regularly outdoors during rainy seasons, so it’s important that any metal structure remains covered when not actually growing plants inside it at all times during those months when it would otherwise be vulnerable

Purchase The Lumber, Bolts, And Other Hardware Needed For Frame

Once you’ve purchased your plastic sheeting (and enough lumber, bolts and other hardware for the frame), it’s time to start building.

You’ll need one piece of 2×4 lumber for each side of the greenhouse. Each side should be about 3 feet tall, so if you want a 6-foot-tall structure then get six pieces of this wood. 

You’ll also need one piece of 1×2 lumber per side—this will serve as a support beam or crossbar that runs along the top edge of each wall. You’ll use these pieces in conjunction with bolts and nuts to fasten them together into frames.

If you don’t already have tools like drills and saws handy, now’s a good time to invest in them; they’re not expensive tools but come in handy all around your house when projects like this come up!

LumberChoose the appropriate type and dimensions of lumber based on project requirements and load-bearing needs.
BoltsSelect high-quality bolts, such as Hex Head Lag Bolts or Carriage Bolts, for secure connections.
Other HardwareGather essential hardware like Brackets, Screws, Nails, and Washers for frame assembly.
FastenersConsider using reliable fasteners like Structural Screws or Decking Screws for added strength.
Structural SupportDetermine if additional hardware, such as Angle Brackets or Tie Plates, is necessary for stability.

Cut The 2×4 Boards According To Your Plan

To begin, you’ll want to cut your 2×4 boards according to the measurements in your plan. You can use either a circular saw or an electric jigsaw (a manual jigsaw will take too long).

If you’re working with a circular saw, measure the length first. Set up your board like so:

  • Place two pieces of wood on top of each other and clamp them into place using C-clamps or other clamps that can accommodate larger pieces of wood
  • Measure the distance from one end of the board to where you’d like it cut (this measurement is for cutting a straight line)
  • Once this is done, remove both clamps and place another piece of wood overtop as shown above so that all three pieces create something akin to a little table

Planning to invest in a tunnel greenhouse? Understanding the cost is crucial. Discover the price range and factors to consider in our informative piece on how much a tunnel greenhouse costs – Find Out, providing you with valuable insights to make an informed decision for your greenhouse project.

Assemble The Frame Using A Drill And Screws Or Bolts

Use a power drill and screws or bolts to assemble the frame. A cordless drill can also be used for this step as long as you have an attachment with a bit that will fit in your holes. 

These are all great things to have on hand around the house if you’re not able to purchase them at the store.

What Kind Of Polyethylene Is Best?

You can use either polyethylene or PVC in building your greenhouse. It’s a matter of personal preference and budget. 

You want to buy polyethylene sheeting that is UV resistant, as this will prevent the plastic from breaking down over time (and potentially letting in insects). The thicker the sheeting you choose, the greater its insulating properties will be.

If you are going to use your greenhouse primarily for tomatoes (which tend to need extra warmth and humidity), consider using a greenhouse plastic that has been treated with sulfur dioxide; this will help keep ants away from your plants

Build Out Endwalls From 2×4 Lumber

To build out your endwalls, you’ll need to make a frame using 2×4 lumber. Drill holes into each board at the ends and along their length, then secure them with screws or bolts. 

Make sure that you have enough room between the wall and cover so that it can open fully. Use a ratchet strap to tighten down the cover on each endwall as well as in between if you’re using more than two panels for each side of your structure (if not, skip this step).

1Measure and cut 2×4 lumber to the desired dimensions for the endwalls.
2Secure the 2×4 lumber together using deck screws or nails.
3Attach the endwalls to the structure using corner brackets or metal connectors.
4Ensure the endwalls are level and plumb using a spirit level or plumb bob.
5Reinforce the endwalls with diagonal bracing for added stability and strength.

Build Out Side Walls From 2×4 Lumber

You can build the side walls from 2×4 lumber and use a polyethylene sheeting to cover the outside of your greenhouse.

If you want to keep the inside of your greenhouse warm, you can use a clear polyethylene sheeting for that purpose instead of covering it with plywood or other materials.

Operating a greenhouse effectively requires knowledge and practical tips. Our easy-to-follow guide on how to operate a green house – Easy Guide provides essential information on temperature control, ventilation, watering techniques, and more, helping you create an optimal environment for your plants’ growth and well-being.

Attach Polyethylene Covering To The Outer Frame.

Attach the polyethylene covering to the outer frame.

  • Attach polyethylene covering to the outside of your greenhouse with ratchet straps or zip ties. Use two ratchet straps on each corner and one in between each side, so you have a total of 12 straps.
  • Make sure it’s taut and tight, but not too tight; you don’t want to damage your polyethylene as you’re pulling on it! If necessary, use a staple gun filled with small staples (or something similar) if needed.
1Measure and cut the polyethylene covering to fit the outer frame.
2Secure the polyethylene covering to the frame using durable clips or staples.
3Ensure the covering is taut and smooth to minimize wrinkles and maximize light transmission.
4Seal the edges of the covering with weather-resistant tape or adhesive to prevent drafts.
5Inspect the attachment periodically and make necessary adjustments or repairs as needed.

Secure Poly Cover With Ratchet Straps

Now that you know what to look for, you will be able to find the perfect greenhouse. To help you make your decision, here are some of the most popular types of greenhouses:

A poly-and-glass combination greenhouse is a great choice if you want to add some natural light and airflow into your home. This type of greenhouse makes it easy to control temperature and humidity within the structure.

A cold frame is an inexpensive way of starting seeds or growing small plants without having to invest in a full-sized greenhouse right away. If you don’t have much space available, this might be the best option for you!

Looking for cost-effective solutions to build a greenhouse for winter? Our detailed article on how cheap you can build a greenhouse for winter offers valuable tips and strategies to create a budget-friendly structure without compromising on quality, ensuring your plants thrive even in colder months.


With a little patience, you can build a greenhouse from plastic and enjoy the fruits of your labor for many years to come. 

Be sure to take care of your greenhouse by periodically checking the bolts that hold down the cover so they don’t rust or loosen over time. 

Also keep an eye out for any small holes where pests could enter through such as mice or squirrels!

Further Reading

Here are some additional resources to explore for further information on building greenhouses out of plastic:

How to Build a Greenhouse Made From Plastic Bottles: This article provides a detailed guide on constructing a greenhouse using plastic bottles, offering creative and eco-friendly solutions.

Build a Plastic Greenhouse: Discover step-by-step instructions and tips for building a plastic greenhouse, including insights into the materials and design considerations.

How to Make a Mini Greenhouse: Learn how to create a compact and portable mini greenhouse with this helpful tutorial, perfect for small spaces or starting seedlings.


How long does it take to build a greenhouse out of plastic?

The time required to build a greenhouse out of plastic can vary depending on the size and complexity of the project. It can take anywhere from a few days to a few weeks, considering the preparation, construction, and assembly processes.

What are the benefits of using plastic for greenhouse construction?

Plastic offers several benefits for greenhouse construction, including its durability, affordability, and versatility. Plastic materials can provide good insulation, allow for controlled light transmission, and resist various weather conditions.

Can I use recycled plastic materials for building a greenhouse?

Yes, using recycled plastic materials for greenhouse construction is an eco-friendly and sustainable option. Plastic bottles, sheets, or even reclaimed plastic panels can be repurposed effectively, reducing waste and promoting environmental consciousness.

Are there any specific considerations for plastic greenhouse design?

When designing a plastic greenhouse, it’s important to consider factors such as ventilation, UV stability of the materials, structural integrity, and the ability to withstand wind and snow loads. Proper design planning ensures a functional and long-lasting greenhouse.

How do I maintain and clean a plastic greenhouse?

To maintain a plastic greenhouse, regular cleaning is essential. Use mild soapy water and a soft cloth or sponge to clean the plastic surfaces, avoiding harsh chemicals that could damage the material. Regularly check for any damages or wear and tear, and make necessary repairs or replacements as needed.