When you’re constructing or updating a greenhouse, one of the most crucial decisions you’ll face is your choice of panel for the walls and roof. Many US growers choose a US polycarbonate greenhouse for its rugged polycarbonate, insulated walls, and having twice the strength of regular polycarbonate. But there’s always one burning question:
What is the best thickness for a greenhouse?
Insulation: This is where your polycarbonate panel thickness is important. The right greenhouse cover can save you money and contribute to your greenhouse flourishing year-round!
Sigma 20 10x7x20ft Backyard Greenhouse Kit
Why Panel Thickness Matters
All in all, it is light, shatterproof, and safe if it should shatter. It is the thickness of the panels that will affect your greenhouse the most. These are the reasons why thicknesses are important:
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Insulating Power – The thicker the panels, the more heat will be trapped, which is of great use in colder states.
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Diffused Light - The correct thickness ensures the right amount of light to reduce its heat and the sun’s dangerous rays.
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Weather Resistant -Thick panels, too, are ideal for heavy snow, winds, and hail.
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Heating Costs - The less expensive thin paneling costs less (obviously), but over time, thicker glass will save money.
If you’re a die-hard gardener, a little extra up-front investment in panel thickness goes a long way.
Sungrow 32 10x8x32ft Greenhouse
General Polycarbonate Panel Thicknesses
In the United States, greenhouse suppliers typically offer 4mm, 6mm, 8mm, and sometimes 16mm polycarbonate in twin- and triple-wall panels. Here’s how they each work:
1) 4mm Polycarbonate Panel
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Great for small hobby greenhouses
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Perfect for hot climates with little to no frost
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Provides minimal insulation
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Affordable choice for beginners
2) 6mm Polycarbonate Panel
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The standard thickness of backyard greenhouses
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High-light transmission with thermal insulation
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Moderate breeze and snow resistant
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Perfect for light to moderate wintry conditions
3) 8mm Polycarbonate Panel
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Includes the highest insulation value
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Less elastic and More firm than the thinner versions
4) 10mm - 16mm Polycarbonate Panel
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Ideal for greenhouses, professional greenhouse
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Spacious enough to withstand heavy snow and strong winds
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It is the most insulated and the most energy efficient
Riga XL 9 14x9x30ft Greenhouse
Determining the Thickness of Your Greenhouse
The optimal thickness of the right panel is determined by three dominant parameters:
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Your Climate
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You can get by with only 4 to 6mm further South in locales like Florida, Texas, and California.
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Northern states, including Minnesota, Michigan, and New York: Insulating layers 8 to 10 millimeters.
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Snow-laden faces: 16 mm panels for strength.
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Your Greenhouse Purpose
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Seasonal growth (spring and summer): 6 mm panels are usually enough.
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For spring, summer & autumn (including winter vegetables), you should consider an 8mm or thicker panel.
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Commercial: 10mm or 16mm panels payback in years and years of durability and lower heating costs.
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Your Budget
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Thin panels = cheaper to purchase, but more expensive for the energy bill.
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Thick panels = expensive up front, and then it pays for itself
MONT 8x8x24ft Black Frame Greenhouse
What Are The Differences Between Single Wall & Twin Wall Polycarbonate Panels
You’ll also want to pay attention to panel type, not just thickness:
1. Single Wall Polycarbonate Panel
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Allows maximum light penetration
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Provides very little insulation
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Perfect for hot areas, or as a temporary structure
2. Twin Wall Polycarbonate Panel
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A dual-layer featuring an air gap in between to provide insulation
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Thermal losing helps keep your room warm and your light soft
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Ideal for year-round growing in mild to cooler climates
Most of the professional grow houses in the USA are built using the twin-wall polycarbonate panels, which are rugged and insulated.
Prestige 2 8x8x16ft Resin Greenhouse
Advice On Maximizing Your Polycarbonate Greenhouse Use
And when you’ve determined the right panel thickness you need, these tips will help you make your greenhouse last and write your own success story:
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Choose UV-Resistant Panels: Avoid the yellowing and help your greenhouse last longer.
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Seal Edges and Connections: A Good seal guards against drafts and moisture migration.
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Keep Good Airflow: Despite its thicker size, the airflow won't be rejected (9.8 goes beyond the limits of the traditional grid) to heat up your laptop.
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Looking Ahead: Somewhat heavier panels will likely be a better investment for the future.
Final Takeaway
The right thickness for your polycarbonate greenhouse panel will all depend on your climate, budget, and growing goals. For the vast majority of backyard gardeners in the US, twin-wall 6mm to 8mm polycarbonate panels are an excellent choice, providing a great balance of light transmission, insulation, and price.
If you live in a cold region or want to grow year-round, double and even triple-wall polycarbonate panels are a wise investment. With the proper panels for your climate, you can enjoy all your plants in all seasons without concern for them to withstand the outdoor conditions.
👉 Want to build the greenhouse of your dreams? Have a look through our polycarbonate greenhouse kit for sale, which ranges from small to large, each suited to any climate or requirement.
With the right panels, your backyard greenhouse can thrive as an all season greenhouse, keeping your plants protected and productive year-round.
