3 Best Roofing Materials for Your Greenhouse (Pros & Cons!)
Are you currently deciding which roofing material is best for your greenhouse? Then, you’ve come to the right place! Your choice of roofing material can either make or break your gardening experience.So, it’s important to start right!
Fiberglass, polyethylene, and double-layered polycarbonate are the 3 best greenhouse roofing materials. They are highly recommended because of their durability, good light distribution, ease of use, and resistance to external forces such as heat and natural disasters.
What are the factors to consider in choosing the best roofing material? Price? Sturdiness? Heat absorption? Maintenance? The list goes on and on, so the best thing you can do at this point is to scroll down to know more!
1. Fiberglass Panels
Fiberglass is one of the best roofing materials for greenhouses due to its durability, cheap price, insulating capacity, even light dispersion mechanism, and ease of transportation and material manipulation. However, it also has downsides such as being prone to yellowing, brittleness, and being harder to clean.
The interesting thing I really like about fiberglass is its versatility. It can be used for commercial gardens, but is also a good investment for home gardens!
You can get fiberglass roof sheets like this one on Ebay!
Another option using the same material is fiberglass woven mat like the one below on Amazon.
Here is a quick summary of the pros and cons of using fiberglass panels as your greenhouse roofing material.
5 Pros of Using Fiberglass
Fiberglass is the superior greenhouse roofing material because of its even light distribution, insulating ability, durability, ease of use, and low cost.
1. Good Light Distribution
Fiberglass panels are known to provide a good light diffusion across the greenhouse. With this feature, plants can produce maximum yield as the material allows for optimum photosynthesis.
2. Insulates the Plants
Too much heat can adversely affect your plants as it leads to leaf burns and easy drying of soil. Luckily, fiberglass panels help in controlling this factor by acting as an insulator for your plants!
Fiberglass panels are also a durable choice that can last even up to 5 years, with proper care and handling.
4. Easy to Work With
Unlike real glass, fiberglass panels can be cut using a handheld saw. This makes this material easy to work with.
Furthermore, flexiglass is also lighter than regular glass. As such, this can be carried easily across your greenhouse area during installation.
5. Relatively Cheaper
Compared to other materials on this list such as glass, fiberglass is a cheaper option. On average, glass costs around 2.50 USD per square foot, while fiberglass only costs around 0.70 USD.
3 Cons of Using Fiberglass Panels
On the downside, fiberglass panels used for greenhouse roofing are prone to yellowing, brittleness, and are difficult to clean.
1. Prone to Yellowing
If you are living in a place where there is excessive heat, you may notice yellowing in fiberglass panels after a year or so. Yellowing is caused by continuous exposure to sunlight which contains UV, thereby degrading the quality of fiberglass due to heat.
However, UV-resistant fiberglass panels are now available in the market.
2. Prone to Brittleness
This disadvantage is also due to extreme heat, but it can also be solved by using UV-resistant fiberglass panels. Extreme heat can make the fiberglass panels crisp, thus, the brittleness.
3. Hard to Clean
If you are using corrugated fiberglass panels, you could experience difficulty in cleaning. You can, however, use a high-pressure water hose to effectively clean every nook and cranny of these panels.
Polyethylene film, unlike fiberglass, is not a strong roofing material because it is made of a plastic polymer. However, it is used because of its low cost, ease of installation, good light distribution, and repairability.
If you are not familiar with plastic polymers, they are the commonly-used plastic in a lot of products such as shopping bags, food cling wraps, toys, and bottles.
Here is a polyethylene roofing that you can purchase on Amazon.
5 Pros of Using Polyethylene
Polyethylene is advantageous for greenhouse roofing because it can withstand high temperatures, is inexpensive, simple to install, is a good light distributor, and is simple to repair.
1. Tolerates High Temperatures
Polyethylene is an ideal greenhouse roofing material because it is made of a thermoplastic polymer, which means that it can endure temperatures of up to 110°C prior to melting.
This feature is also useful to protect your plants from heat burns caused by extreme temperatures.
But how about during cold seasons? What can you do?
Explore more on this topic in our article on kerosene heaters.
2. Easy Installation
Since it is made from plastic and rolled, it is easier to carry and install polyethylene.
It is also easier to cut with only scissors, compared to the others in this list which must be cut using a handheld saw.
3. Good Light Distribution
Though its transmission of light is not as good as glass, polyethylene still provides sufficient lighting that can promote the growth and development of your greenhouse plants.
4. Easy to Repair
Considering that polyethylene material is plastic, we can totally agree that there could be high chances of damage. However, you can easily repair these damages (e.g. holes and tears), with a repair tape like the one below on Amazon.
Compared to the other materials in this list, polyethylene is the cheapest! This is the reason why this is being used by a lot of garden beginners. On average, it only cost around 0.12 USD per square foot!
It can last up to only 2 years, but most gardeners see it as a more economical choice because there is a lower initial investment needed. Thus, if you are gardening for business, you can easily see a return on investment in months!
Another factor that makes polyethylene cheaper is that there are less structural components (like specialized frames) required to support the polyethylene roofing.
5 Cons of Using Polyethylene
Some disadvantages of using polyethylene for greenhouse roofing include its lack of aesthetic appeal, susceptibility to damage, lack of durability, shorter lifespan, and not being environmentally friendly.
1. Not Aesthetic
We must confront it. Despite all of its promising benefits, polyethylene is not an attractive material to use, especially if you are developing an agri-tourism garden.
But if you are only gardening in your backyard, you do not need to be concerned about this disadvantage.
2. Prone to Damage
Damage is the number one enemy of greenhouse polyethylene roofing. This may come in the following forms:
- Holes from beaks or claws of birds;
- Tears from falling branches; or
- Accidental mechanical damage from human activities (e.g. flying baseballs).
However, this disadvantage can be prevented by choosing a polyethylene grade that is thicker!
Select the thick grades of polyethylene films for greenhouse roofing by looking at the ‘mil’ in the product. The higher the mil number, the thicker the polyethylene plastic.
For instance, the product below on Amazon, is 6 mil, thus it is thicker than those 2 and 4 mil variants.
3. Not Sturdy
If you live in an area prone to natural disasters such as hurricanes, using polyethylene may not be a good idea. They can be seriously damaged by high winds and heavy rains.
4. Short Lifespan
As mentioned earlier, polyethylene roofing must be replaced every 2 years, because it may become yellow and brittle as well.
However, some gardeners use polyethylene only for a specific season. Some gardeners in arid areas roll their polyethylene plastic roofings during the summer to lessen damage caused by tremendous heat.
Another disadvantage of polyethylene plastic roofing is that it is not biodegradable and thus is not environmentally friendly. As a result, if you replace them every two years, you will also have waste products every two years.
3. Double-Layered Polycarbonate
Using double-layered polycarbonate is a newer approach compared to using fiberglass panels and polyethylene. It is gaining attention since it is a very strong material and can tolerate adverse conditions such as heat, force, and even calamities.
You can get double-layered polycarbonate roofing panels like this from Ebay.
4 Pros of Using Double-layered Polycarbonate
Using double-layered polycarbonate roofing is advantageous because it can withstand extreme external forces, lightweight, easy to work with, resistant to fading or discoloration, and long lasting.
1. Strong Material
Polycarbonate is durable and can endure tremendous forces from heat, mechanical damages, and heavy rains.
Interestingly, polycarbonate comes in bullet-resistant types that are used in items like police shields. Thus, this material is a widely used material for garages, patios, and gardens.
2. Lightweight and Easy to Work With
This material is much lighter than glass, which is also a common roofing choice! This feature makes it easier to transport and mobilize when installing it in a greenhouse.
3. Resistant to Fading or Discoloration
As it is a strong material, double-layered polycarbonate is also a weather tolerant option! It can withstand high or low temperatures and even impacts from rains and snow. It can last for many years without fading or discoloration!
Learn more about the ideal greenhouse color in our article on greenhouse colors.
4. Long Lasting
How many years? You might ask. Considering the above mentioned features, polycarbonate roofing can last at an average of 10 years! That is a very long period to have a huge return on investment, if you are into a commercial greenhouse.
2 Cons of Using Double-Layered Polycarbonate
Using double-layered polycarbonate sheets also comes with 2 drawbacks: it can be scratched and dented and it can be expensive to buy upfront.
This greenhouse roofing material only has two disadvantages. Surprising, isn’t it?
1. Can Be Scratched and Dented
Double-layered polycarbonate sheets are not scratch and dent resistant.
But, how can these be prevented? The only way to prevent these from happening is to properly care for it, from installation to utilization.
2. Has High Investment Costs
Another disadvantage is having a higher initial investment. However, as mentioned earlier, it can last for 10 years, thus, it is also a good investment for a commercial greenhouse farm.
But if you are just beginning to explore gardening and are planning to build a small greenhouse, the first two options might be better for you.
Is Glass a Good Material for Greenhouse Roofing?
Glass is a strong, diffusing, low-maintenance, and aesthetic material that can effectively distribute light in greenhouses. However, it is not recommended because it is expensive, requires special care, provides no insulation, is difficult to repair, poses garden hazards, and requires highly knowledgeable experts during installation.
3 Pros of Using Glass Roofing
- Strong. Glass is a stronger material compared to fiberglass and polyethylene.
- Good light diffusion. Since glass is a transparent material, it can distribute light well inside the greenhouse.
- Low maintenance. Cleaning glass roofing is easier since it can just be splashed with water and soap.
- Aesthetic. Using glass elevates the aesthetics of your garden.
6 Cons of Using Glass Roofing
- Expensive. A square foot of glass costs around 2.50 USD on average.
- Requires special care. Since it can be broken with external strong force, extra caution must be considered.
- Provides no insulation. Heat can still go inside the greenhouse if glass is used.
- Difficult to repair. When broken, it will require glass experts and may cost high.
- Poses garden hazards. Using glass, especially when broken, poses a risk for wounds, thus you will need extra caution.
- Requires technical knowledge during installation . You cannot put the glass by yourself, it must be installed by knowledgeable people for best use.
So instead of building a greenhouse that’s completely made out of glass, consider the top 3 roofing options I mentioned earlier on in the article.
What is the best color for a greenhouse roof?
The best greenhouse roof color is clear. A clear roof will allow enough light to enter the greenhouse, maximizing plant yield. When colored roofs are used, they may prevent light from entering the building. Opaque roofing can also be used provided that there are sufficient grow lights in the greenhouse.
Are nets good for greenhouses?
Nets provide shading, so if the goal is to maximize harvest, the net will reduce productivity inside the greenhouse. Nevertheless, nets can be used to prevent leaf burning in arid areas where the sun becomes too intense and shade is necessary.
Summary of Best Roofing Material for Greenhouse
The best roofing materials for greenhouses are fiberglass panels, polyethylene, and double-layered polycarbonate. Their durability, good light distribution, ease of use, and resistance to external forces such as heat and natural disasters make them ideal.
Glass can be used as a roofing material, but it is not recommended for commercial and home greenhouses. This is because it is costly, necessitates special care, provides no insulation, is difficult to repair, poses garden hazards, and necessitates the services of highly knowledgeable experts during installation.
- “Greenhouses” by College of Agriculture and Life Science in University of Arizona
- “Greenhouse Structures” in Texas Agricultural & Mechanical University