What Happens to Polycarbonate Over Time in a Greenhouse?

Polycarbonate has become one of the most popular materials for greenhouse construction due to its strength, transparency, and insulation properties. But what happens as time goes by? Will polycarbonate panels in your greenhouse stay crystal clear and strong for decades, or will they degrade with sunlight and weather?

If you’re investing in a commercial greenhouse or replacing an aging cover, understanding how polycarbonate behaves over time can help you make smarter decisions. In this article, we explore the science behind polycarbonate aging, the factors that influence its longevity, and practical maintenance strategies to extend its lifespan.

1. What Is Polycarbonate and Why Is It Used in Greenhouses?

Polycarbonate is a thermoplastic material that is lightweight, impact-resistant, and naturally transparent. In greenhouse applications, it’s commonly used in two forms:

• Twin-wall or multi-wall polycarbonate sheets (for insulation and structure)

• Solid polycarbonate sheets (for high-impact or transparent applications)

Farmers and commercial greenhouse builders often prefer polycarbonate over glass and film due to its:

• UV resistance (with coating)

• High thermal insulation

• Lightweight and shatterproof properties

• Cost-effective installation and maintenance

2. How Does Polycarbonate Age Over Time?

Despite its durability, polycarbonate does not last forever. Over the years, greenhouse panels face continuous exposure to:

• Ultraviolet (UV) rays

• Extreme temperature fluctuations

• Wind, dust, and rain

• Chemical exposure from pesticides or cleaners

These factors lead to gradual deterioration in performance and appearance.

3. Common Signs of Polycarbonate Aging in Greenhouses

Here’s what typically happens to polycarbonate panels over time:

✅ a) Yellowing and Discoloration

Even with UV protection, polycarbonate can start to yellow after 8–10 years, especially in areas with high sunlight exposure. Yellowing reduces light transmission and affects crop growth.

✅ b) Loss of Light Transmission

A new polycarbonate sheet can transmit up to 80–90% of natural light. After prolonged exposure, this may drop significantly, affecting photosynthesis inside the greenhouse.

✅ c) Brittleness and Cracking

Long-term exposure to UV and cold weather makes polycarbonate brittle, increasing the risk of cracking or impact damage.

✅ d) Loss of Insulation Performance

Over time, internal dust buildup and micro-cracks reduce the panel’s thermal insulation, affecting the internal climate control.

✅ e) Surface Scratching or Algae Growth

Frequent cleaning or wind-blown debris can cause surface wear. In humid areas, greenhouses may also develop algae buildup on surfaces, accelerating material wear.

4. Factors That Influence Polycarbonate Lifespan

Several variables affect how quickly polycarbonate degrades:

5. Maintenance Tips to Extend Polycarbonate Lifespan

Here’s how to slow down the aging process of your greenhouse panels:

✅ a) Clean Gently and Regularly

Use mild soapy water and a soft cloth. Avoid ammonia-based cleaners or abrasives.

✅ b) Inspect Seals and Edges

Water or dust infiltration inside twin-wall panels can lead to fogging and microbial growth. Check and reseal if needed.

✅ c) Install with UV-Side Facing Outward

Make sure the UV-coated side is installed facing the sun—manufacturers usually mark it.

✅ d) Add Shade Netting

Installing shade netting or whitewash during intense summers can reduce UV stress on the panels.

✅ e) Replace Individual Sheets, Not Entire Panels

Most modular greenhouse designs allow individual sheet replacement, saving costs when a few panels degrade.

6. When Should You Replace Polycarbonate Sheets?

You don’t always need to replace your entire greenhouse cover. Here are signs it’s time:

• Light transmission is visibly reduced

• Sheets have visible cracks or punctures

• Internal condensation or mold is trapped

• Crops show reduced productivity due to poor lighting or temperature variation

Typically, high-quality polycarbonate panels last 10–15 years, while some advanced UV-protected sheets may go up to 20 years with proper care.

7. Polycarbonate vs. Other Greenhouse Coverings Over Time

Conclusion: Plan for Polycarbonate Aging Like You Plan Your Crops

Polycarbonate is a fantastic material for greenhouses, but like everything in agriculture, it has a life cycle. By understanding the aging process, watching for early signs of wear, and applying proactive maintenance, you can extend the lifespan of your investment—and keep your plants thriving year-round.

Looking for replacement polycarbonate sheets or custom greenhouse solutions?

Contact our team today for expert recommendations and factory-direct pricing.