Greenhouse roof, side walls, gables, nursery areas, high-humidity zones — not all glass is suitable for the same position.

Right glass = 10–20% higher yield + 25% heating cost savings + 50%+ disease reduction

Many people think greenhouse glass is just a light-transmitting panel — as long as it's strong and clear, that's enough.

That is a mistake.

Even in the same greenhouse, the glass used on the roof and the glass used on the side walls have completely different requirements. Use the wrong glass in the wrong place, and at best you lose yield; at worst, diseases run rampant and winter heating bills skyrocket.

We have been exporting greenhouse glass for nearly a decade, serving tomato greenhouses in the Netherlands, rose farms in the Middle East, and nursery facilities in Canada. Today, this article tells you: what glass should be used in different positions, and what are the advantages?

 

I. Greenhouse Roof — Must Use Diffuse Glass

The Problem:
Regular clear glass lets sunlight shine straight down. In summer, strong sunlight causes leaf sunburn and fruit blemishes. Moreover, only the top leaves receive light; the middle and lower leaves are in perpetual "shade," photosynthesis suffers, and yields naturally drop.

The Benefits:

Turning direct light into "soft light"
It's like installing a giant "softbox" over the greenhouse. Sunlight is diffused as it enters, spreading evenly across every leaf — from top to bottom, every leaf "feeds" on light. Diffuse glass offers a haze of 50–70% and light transmittance of ≥91.5%. Depending on the climate and sunlight conditions of different countries, single-sided or double-sided anti-reflective coatings can be applied to further increase light transmittance, allowing more light into the greenhouse.

No hot spots, no shadows
Diffuse glass improves light uniformity from 0.6 (with regular glass) to over 0.85. Even the lowest leaves can photosynthesize, resulting in more uniform and larger fruit.

Prevents leaf burn
In summer, there's less need to frequently draw shade screens, saving on labor costs and keeping crops stress-free.

In short:
Diffuse glass isn't about letting in more light — it's about making every ray of light count.

II. Greenhouse Side Walls — Low-E Glass or Ultra-Clear Float Glass Recommended

The Problem:
Side-wall glass doesn't need to be responsible for light diffusion like the roof, but it has two important jobs:

l People outside should be able to see the crops inside clearly (for display, inspection, and tours).

l In winter, it must not let heat escape, or heating bills will become a bottomless pit.

The Solution: Low-E Glass or Ultra-Clear Float Glass

The Benefits:

Low-E Glass: Warm in winter, cool in summer
Its surface has an invisible metallic coating that reflects indoor heat back inside. Field data shows that on winter nights, greenhouse temperatures can rise by 3–5°C, cutting heating costs by 25–30%. In summer, it also blocks outside infrared heat — a double win.

Ultra-Clear Float: High transmittance, true color
For clients on a tighter budget, or those growing crops with lower light requirements, 4mm ultra-clear float glass is a cost-effective choice. With light transmittance above 91.5% and true color rendering, it makes monitoring crop growth easy. Tempered versions are also available.

Side walls don't need diffusion — because the sunlight has already been diffused once by the roof glass. The side walls' main job is insulation and supplemental lighting, not diffusion.

In short:
Side-wall glass needs to retain heat and provide clear visibility. Don't use roof glass on the walls.

III. Greenhouse Gables — Must Use Tempered Glass

The Problem:
Gables are the most wind-exposed parts of the entire greenhouse. During typhoons or strong winds, regular glass shatters easily. Broken glass falling into the greenhouse not only injures people and damages crops, but also requires shutting down production for cleanup — the losses are enormous.

The Solution: Tempered Glass

 

The Benefits:

5 times stronger than regular glass
Withstands wind loads up to 120km/h and snow loads of 80–100 kg/m². When tempered glass breaks, it shatters into small, blunt fragments resembling corn kernels — no sharp edges to cut workers or damage crop leaves.

Meets international safety standards
Exports to the EU require compliance with EN 12150, and to the US with ANSI Z97.1. Every piece we ship carries traceable screen-printed markings for smooth customs clearance.

In short:
Gable glass doesn't need high light transmittance — but it must be strong, safe, and wind-resistant.

IV. Nursery Area — UV-Blocking Glass Recommended

The Problem:
Young seedlings are extremely sensitive to light. Uneven light or excessive UV causes "leggy" growth — thin, weak stems and underdeveloped roots, leading to low transplant survival rates.

The Solution: UV-Blocking Glass

The Benefits:

Controls leggy growth, promotes sturdy seedlings
By filtering out a portion of UV light, seedlings focus their energy on thickening stems and developing roots, rather than shooting up.

Uniform seedlings, easy transplanting
Entire trays of seedlings grow to the same height, saving labor during transplanting and improving field survival rates by over 10%.

In short:
Use the right glass for nursery, and you'll recoup your investment in a single season.

V. High-Humidity Regions (Tropical & Subtropical) — Must Use Anti-Drip Glass

The Problem:
With significant temperature differences inside and outside the greenhouse, condensation forms on the glass surface every morning. Droplets accumulate and fall — right onto the flowers and leaves of tomatoes, cucumbers, and roses. This directly triggers botrytis and downy mildew.

The Solution: Anti-Drip Glass

The Benefits:

Water doesn't drip — it spreads into a thin film
The anti-drip coating causes condensation to spread evenly across the glass surface and flow down along the glass, without forming falling droplets.

Disease reduced by over 50%
Leaves and flowers stay dry, cutting fungicide use in half. For export-grade cut flowers and supermarket tomatoes, that's pure profit.

Effective year-round
Whether in winter or rainy season, no matter how high the humidity inside, there's no "rain" under the glass.

In short:
Anti-drip glass isn't about letting in more light — it's about preventing your crops from being sickened by their own "breath."

Summary: The Golden Rule of Glass Selection

A truly good greenhouse glass is not the thickest, not the most expensive — but the one placed in the right position.

Who We Are？

Planti is a professional greenhouse glass manufacturer.

From tomato growers in the Netherlands to rose farms in the Middle East, from nursery greenhouses in Canada to leafy-green farms in Southeast Asia — what we provide is not just a piece of glass, but a complete "glass-by-position" solution.

We can help you:

l Recommend the most cost-effective glass combination based on your client's climate zone and crops

l Provide full technical specifications including haze, light transmittance, U-value, and more

l Ensure safe shipping with pallets + wooden crates + edge protection — sea-freight damage rate below 0.5%

l Support with CE, ANSI, JIS, and other certification documentation

Want to put together the right greenhouse glass package for your client?

Just send us three details:

l Which country is the greenhouse in? (Winter minimum temperature? Summer maximum temperature?)

l What is the main crop? (Tomatoes, roses, leafy greens, or nursery?)

l Which part? (Roof, side walls, or the entire greenhouse?)

We'll provide you with a tailored solution. Contact us: info@plantinc.com