Do Greenhouses Need a Clear Roof

Do Greenhouses Need a Clear Roof?

Dreaming of growing your favorite vegetables all year round? The greenhouse is the ultimate source that might provide you and your family with non-seasonal food without much hassle. 

However, there’s a strong debate around the globe regarding if a greenhouse should have a clear roof or not? You’ll get your answer by the end of this article.

Why Do Greenhouses Need A Roof?

First things first, you must know the reasons why you need a covering on the roof once you have the perfectly-made greenhouse!

There is no single reason for the fact as the benefits of covering for the sprouting of seeds and immense growth of crops is enormous. Here’s why greenhouses need to be covered at first.

Enough Amount of Light:

The amount of light that reaches the soil inside the greenhouse decides the fate of plants. The roof of the greenhouse can reflect as well as refract the light, depending on the material employed. 

For example, fiberglass roofing tends to diffuse much light over the years and can completely block the path.

On the other hand, glass filters less light and transmits more, providing more chances for seed sprouting and optimum growth.

Maintain the Temperature:

A transparent or opaque roof can be a reason for a humid and hot environment inside a greenhouse. In this regard, Glass roofing traps the heat and humidity inside the greenhouse, reducing the chances of escape. 

On the other hand, fiberglass is terrible at providing insulation properties to a conservatory.

Plastic films are also getting their fame these days due to being a weather-tight solution for these greenhouses; growing crops all-year-round.

Which Is Better – Opaque Vs. Clear Greenhouse Roof:

As mentioned in the previous section, roofing plays a significant part in controlling light, heat, and humidity inside the greenhouse, in turn, the effective growth of plants.

But does the greenhouse roof need to be clear or opaque? In practical terms, both experience their own pros and cons depending upon the type of crop or vegetation you’ve selected.

‘’As a first-time grower, if you’re looking only to germinate the plants inside the greenhouse soil, clear plastic can upsurge the benefits a lot.

On the other hand, if you want your crops to mature inside, getting an opaque roof for your greenhouse is a must.’’

Confused? No worries!

To understand better, here’s a more profound concept- direct and diffused light!

Direct light is what you get in consequence of a clear roof, consisting directly of the sun rays, heating the soil to a greater extent.

This will, in turn, encourage the germination and sprouting of seeds. 

On the contrary, a diffused light will scatter all around in the greenhouse upon entering, giving a mild and soft effect, reaching both the lower as well as upper leaves in a balanced way.

Now, you know when to use the clear roof and opaque roof for your greenhouse to grow all year round! 

What Type Of Materials Forms The Greenhouse Roof?

Regarding the clear as well as opaque roofs, here are some of the materials that can be effective in extending the growing season for your crops.

Weigh the pros and cons of each material and let them be the weather shield and a protective covering for your greenhouse.

Fiberglass Greenhouse Roof:

One of the most commonly used greenhouse roof materials is fiberglass due to being durable for up to 20 years or more.

Providing versatility in type, fiberglass comes in a clear, green, and frosted coating to grow what you like! However, while buying, make sure to buy clear greenhouse fiberglass for better light penetration (78 to 90%). 

Plastic Greenhouse Roof:

Plastic, especially Polyethylene sheets, are the inexperienced choice in setting up the greenhouse.

They cost nearly 20 cents per square foot and can last more than a year or two, depending on the place you live in!

One noticeable feature of plastic sheets is the versatility in sizing. You can get 2mm, 4mm, or 6mm as per the light you want to transmit.


Extending the growing season while getting the favorite vegetables all year round is bliss- only possible due to greenhouses.

Though, roof covering is one such factor that decides the fate of plants inside.

Using a clear roof for the greenhouse can transmit the direct sun rays and encourage the seed sprouting, while opaque ones are perfect for taller plants that need a diffused heat and light.

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