Anyone who builds a greenhouse themselves is faced with the question of what material the roof should be covered with during planning. Here we present different variants and their advantages and disadvantages.
With a small greenhouse, you gain flexibility and a lot of gardening freedom. In the future, you won't have to worry about the thermometer, because nothing can happen to plants in the greenhouse. Suddenly bonsai and tropical plants also feel at home in your garden and from now on pregerminating and growing the plants will be child's play.
Before the greenhouse is set up, not only should the location be determined, but also the material for covering your new small greenhouse should be found. Below you will find out which roofing options are available to you and which materials are most suitable.
Glass versus Plastic
Our grandparents used to garden in glass greenhouses. Back then, glass was the first choice and also the only available roofing for greenhouses. There was a lack of flexible and up-to-date alternatives. Today the glass greenhouse can still be found here and there, but has actually become more of an exception. Although glass is easy to clean, it is also dangerous. Glass is heavier and less flexible than plastic. The greenhouse must have a particularly strong structure to withstand the weight.
If glass breaks, a he alth hazard cannot be ruled out. Plastic is not only lighter, but also more flexible. The material does not break and can easily withstand storm damage.
Shattering glass is a security risk that should not be underestimated.
If the glass wall collapses, tidying up is the order of the day. Even the smallest splinters should not be overlooked, because if they remain in the ground, you can severely cut your hands while gardening.
Which material is easier to process?
Here too, the answer is very clear: plastic. You can easily cut plastic panels with a jigsaw or aCut hand circular saw.
» Tip: Make sure you use a fine circular saw blade so that the material does not splinter.
You have to be much more careful when processing glass. One wrong move is all it takes for the glass to splinter and crack.
» Tip: Cordless hand-held circular saws and jigsaws, which do not require you to be dependent on a socket, are ideal for working outdoors.
What type of plastic can be used for roofing?
The term plastic covers a wide range of products and thus presents the hobby gardener with the question of which plastic is the right material for the small greenhouse. When it comes to roofing, Makrolon and Plexiglas are the preferred terms. Makrolon is a brand name and actually stands for polycarbonate. Plexiglas or acrylic glass are also common names for a type of plastic called polymethyl methacrylate.
Advantages and disadvantages of the two plastics
| Plastic | Advantages | Cons |
|---|---|---|
| Makrolon | ✔ transparent ✔ weatherproof ✔ easy to edit | ✘ expensive to buy ✘ sensitive to scratches ✘ yellowing may occur |
| Plexiglass | ✔ visually almost indistinguishable from real glass ✔ not sensitive to scratches | ✘ difficult to work with ✘ can chip |
Smartphone glass as an innovative solution of tomorrow
If we are talking about covering small greenhouses, smartphone glass is definitely still a thing of the future, but it is already being discussed. A corresponding study was carried out in the Netherlands. Scientists in Wageningen have investigated whether this thin and flexible glass is suitable for covering greenhouses. The focus of this project was thinking about innovative energy savings. Various layers of glass were experimented with. Compared to the energy savings in a Venlo Energy greenhouse when growing vegetables without light, more than half of the energy could be saved with double glazing on smartphone glass.
The possibilities of being able to cover greenhouses in a particularly energy-saving manner in the future are therefore definitely given with the very thin and robust glass panels. The thin glass is specially hardened and is therefore far more stable than conventional glass.
» Tip: Smartphone glass can also be made in a curved shape.
A nano-coating ensuresthat the glass reflects less and becomes more translucent. The light transmission of multi-layer smartphone glasses can even surpass the multi-layer hollow-core polycarbonate sheets that are currently in widespread use.
It remains to be seen whether the material will be able to establish itself in the manufacture of small greenhouses. The high price and the limited dimensions could speak against it.
Use foil as cover - does that make sense?
One can certainly have different opinions on this. The advantages and disadvantages of the foil greenhouse are probably balanced. It is of course quite inexpensive to cover the small greenhouse with foil. If you want to get a feel for the hobby of gardening in a greenhouse, you will certainly find a simple and inexpensive option here. The foil greenhouse is quickly set up and you do not need a foundation. If the film tears, it can be temporarily glued or simply replaced.
Of course, the disadvantages should not remain unmentioned. A greenhouse covered with foil is not really an eye-catcher. In a closed plastic greenhouse, the humidity increases rapidly and this leads to a climate that promotes fungal and pest infestation.
» Reading tip: Climate in the greenhouse - 4 tips
» Tip: Poly greenhouses should have ventilation options.
A poly greenhouse should be dismantled in autumn. You won't be able to garden here all year round, because the foil greenhouses are not insulated, so it makes little sense to heat them here. In addition, films have a very limited shelf life and would certainly collapse under the weight of snow and ice.
Efficient covering of small greenhouses - what do you have to pay attention to?
- Value
- Permanence
- Transparency
- Ease of use
- UV resistance
- Insulation
- Roof Pitch
Why is the pitch of the roof so important?
The inclination of the greenhouse is particularly important so that no rain accumulates on the flat surface or masses of snow in winter cause the greenhouse to collapse. If the roof is inclined, it can practically clean itself. If the angle is large enough, the water runs off quickly and cleans the roof surfaces.
» Tip: Most manufacturers use a roof pitch of about 26 degrees.
This has another advantage, the light can be reflected particularly well if it is at a rather obtuse anglehits.
Which points should you pay particular attention to when choosing the roofing?
❖ Insulation Value
The different materials differ in their insulating value.
» Tip: The insulation value can be found in a k-value or in a u-value.
The insulation value is particularly important for you if you want to use the small greenhouse all year round. If you only want to garden in the greenhouse in spring and summer, you will place less value on thermal insulation than hobby gardeners who want to use the small greenhouse all year round.
Warning: Think carefully about your priorities beforehand, because retrofitting can be expensive.
Low insulation values can often only be achieved if low light transmission is accepted at the same time. So then mostly instead of the conventional double-walled panels, triple-walled panels are used.
❖ Translucency
When choosing the covering, you should consider that as much light as possible should penetrate your greenhouse. Because every plant needs sufficient light. Light transmission is an important criterion, especially for year-round use. Just think of the extremely dark days in November and December.
When choosing the translucency, you should pay attention to the following details:
- Material
- Layers
- Density
- Coatings
With coverings made of common plastics, the light transmission is about the same and is around 92 percent and 16 millimeters. Less light falls through triple-wall sheets than through double-wall sheets. The web density is also important in this context. Web plates with an X-profile, for example, ensure stability, but at the same time a lot of light is lost due to the narrow position of the webs. Any coatings are also at the expense of the incidence of light.
❖ UV resistance
If you use a covering without UV resistance, you may pay less, but you will probably also be less happy with your new greenhouse, because if the material is not UV-resistant, it quickly becomes unsightly, yellows and shows cracks. Less light automatically reaches your plants. Dirt can get stuck in the cracks and the incidence of light is further reduced. The coverings often have to be replaced after a short time because not enough light reaches the plants and the panels have simply become unsightly.