When it comes to greenhouse construction, few materials match the durability, light diffusion, and thermal efficiency of polycarbonate sheets. But what thickness of polycarbonate is best for your greenhouse? The answer depends on your climate, budget, and what you're growing.
In this guide, we’ll help you understand the differences between polycarbonate thicknesses and how to choose the right one for your greenhouse project.
Polycarbonate has become the top alternative to glass and polyethylene film due to its:
High impact resistance
Excellent thermal insulation
UV protection
Long lifespan (up to 10–15 years)
Lightweight and easy to install
But not all polycarbonate is created equal—thickness matters.
| Thickness | Common Use | Thermal Insulation (U-Value) | Light Transmission | Cost |
|---|---|---|---|---|
| 4mm | Small DIY greenhouses, internal partitions | ~3.9 W/m²K | ~85% | Low |
| 6mm | Hobby greenhouses, mild climates | ~3.5 W/m²K | ~80% | Low–Mid |
| 8mm | Commercial greenhouses, windy areas | ~3.0 W/m²K | ~75% | Medium |
| 10mm | Cold climates, snow load areas | ~2.7 W/m²K | ~70% | Mid–High |
| 16mm+ | Harsh winters, passive solar greenhouses | ~2.3 W/m²K | ~65% or less | High |
Mild Climates: 4mm or 6mm is usually enough for insulation and wind protection.
Cold or Snowy Regions: 10mm+ is recommended for better insulation and structural integrity.
Tropical crops or short-cycle vegetables: 6mm–8mm works well.
Delicate flowers, orchids, or climate-sensitive plants: Go for 10mm or 16mm for stable temperature control.
Thicker polycarbonate offers better performance, but it’s more expensive.
For budget-limited projects, 6mm twin-wall polycarbonate offers a balance of cost and insulation.
In areas with strong winds or snow, thicker panels (10mm–16mm) provide more strength.
Thinner sheets are fine for small-scale backyard greenhouses or indoor nursery use.
Single-wall: Lightweight, lower cost, lower insulation; best for seasonal or temporary greenhouses.
Twin-wall (Double-layered): Standard for most greenhouses; provides insulation and strength.
Multi-wall (Triple/Quad): Higher insulation, better energy savings, used in high-end commercial or industrial greenhouses.
Pro Tip: For commercial greenhouses in colder climates, multi-wall 10mm+ sheets offer long-term energy savings.
As thickness increases:
Insulation improves (lower U-value = better).
Light transmission decreases.
Finding the sweet spot is key:
6mm twin-wall: ~80% light, decent insulation.
10mm twin-wall: ~70% light, better heat retention.
If light diffusion is crucial (e.g., for flowering plants), avoid overly thick sheets unless using anti-glare coatings.
4mm–6mm: Can be mounted on lighter frames like aluminum or galvanized steel.
8mm–10mm: Requires more robust structure to handle the panel weight and wind load.
Use UV-coated side facing outward to prevent yellowing or cracking.
Also, seal edges properly to prevent water and dirt buildup between layers in twin/multi-wall sheets.
While thicker panels have a higher upfront cost, they can:
Reduce heating expenses by up to 30%
Last longer in extreme conditions
Reduce crop loss due to climate stress
However, if your greenhouse is only seasonal or short-term, 4–6mm is often sufficient.
Malaysia – 6mm Twin-Wall for Orchid Houses: Good humidity retention and moderate cooling.
Netherlands – 10mm Multi-Wall for Rose Greenhouses: Maximum climate control for high-value crops.
USA Midwest – 16mm for Passive Solar Greenhouses: Thick walls help maintain internal heat through harsh winters.
| Use Case | Recommended Thickness |
|---|---|
| DIY Home Greenhouse | 4mm or 6mm twin-wall |
| Commercial Veggie Farming | 6mm or 8mm twin-wall |
| Cold Climate Crop Farming | 10mm+ multi-wall |
| High-End Flower Production | 10–16mm with UV/IR coating |
The ideal polycarbonate thickness for your greenhouse depends on your location, crops, and budget. While 6mm twin-wall polycarbonate fits most needs, upgrading to 10mm or even 16mm is worth it for long-term energy savings and plant protection.
Not sure what thickness you need? Contact our team for expert recommendations tailored to your greenhouse goals.
Need Help Choosing Polycarbonate?
We’re a factory specializing in commercial greenhouses and polycarbonate structures. Whether you're building a small farm tunnel or a large-scale facility, we’ll help you choose the right materials for success.
+86 189 2488 9901 +86 189 2455 5194
+86 189 2488 9901 +86 189 2455 5194
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