Choice of greenhouses: frame and materials
To start with the framework of the greenhouse
Since the frame of greenhouses requires significant manufacturing accuracy, it is worth using ready-made solutions from modular industrial designs.
The frame assembly of such a greenhouse is carried out on site using special terminals and bolted connections in a few hours. At the same time, fasteners, terminals, connecting elements can be used both metal and from ermammide - specialized high-strength plastic.
The frame of the greenhouse is leveled and firmly fixed in the ground with the help of a foundation or T-shaped joints. For a light greenhouse, the second option is better, since it makes it possible to transfer the greenhouse if necessary. On the other hand, for a stationary greenhouse it is still necessary to provide a foundation.
An interesting option is greenhouses with a frame made of PVC profile and a roof made of cellular polycarbonate. This profile does not require drilling holes during installation of the greenhouse, allows you to adjust the number of layers in the coating of the greenhouse. However, the high cost of such a structure does not always pay for its advantages.
Greenhouse coating materials
The roof of the greenhouse should be transparent and let in the light necessary for the plants. On the other hand, it must have a low thermal conductivity and it is good to keep heat inside the room. The better the greenhouse retains heat, the less temperature fluctuations, the amount of condensate and the cost of heating. In addition, the greenhouse must be resistant to sudden temperature fluctuations.
The most ancient variant of a greenhouse roof is a glass roof. Its advantages are resistance to sunlight and frost. However, such a roof is fragile, heavy and requires constant monitoring of joints on leaks. In addition, glass greenhouses need a very powerful frame that can support their weight, and the foundation on which the structure will be based.
With the advent of synthetic film materials, transparent films have received the widest distribution among fans of greenhouse business.
Their advantages are low cost of material and ease of sealing joints. Most modern industrial greenhouses are covered with a film. Disadvantages - relative fragility, fragility and poor ability to retain heat. A single-layer film coating is suitable only for summer greenhouses.
In any case, when choosing a hothouse film, it is worth purchasing UV-stabilizing, with a service life of 24-36 months and a thickness of at least 120 μm. The thicker the film, the warmer it is and stronger, but the light is worse. However, modern films let pass at least 80-90% of sunlight.
A three-layer bubble film is an innovative development based on the usual polyvinyl chloride film in which air bubbles are soldered between the inner and outer layers. Its closest analogue is bubble packaging film. It is much warmer than usual and approaches the cellular polycarbonate in terms of heat-saving properties.
Today, cellular polycarbonate is one of the most common materials. It consists of several (at least two) layers of polycarbonate separated by a layer of air. It is strong, durable, retains heat well thanks to its cellular structure. The multi-layer roofing allows you to maintain high tightness of the greenhouse.
To ensure that the roofing material has been used for a long time and without problems, we should pay close attention to the quality of polycarbonate. First, only polycarbonate is suitable from primary raw materials, with UV protection and high material density.
So, 4-mm polycarbonate should have a density not lower than 0,65, and 6-mm - 0,85 kg / m2. It is very important to make sure that the material is certified and has quality assurance. The cheaper polycarbonate from secondary raw materials, low density, will not be stable enough and will quickly collapse under the influence of sunlight. At the same time, for a quality material, the service life will be at least 10 years.
The higher the polycarbonate thickness, the higher the thermal insulation properties of the material. therefore 4-6 mm - the best option for unheated, summer greenhouses. A well-sealed greenhouse made of such a material will reliably protect plants from frost to 4-5 ° C. For a winter greenhouse in our area, polycarbonate with a thickness of at least 8 mm should be used. An interesting option for the greenhouse is polycarbonate nano.
This innovative material, thanks to specialized additives in plastic, skips the maximum of the red and blue-violet rays, cutting off the unproductive green. This greatly accelerates the growth of plants and increases their yield.
In addition, the greenhouse made of pinkish polycarbonate is very beautiful and looks original on the site. When installing a polycarbonate greenhouse, it is definitely worth using specialized fasteners, trims and profiles - this will significantly increase the durability and tightness of the greenhouse.
Ventilation in the greenhouse is an absolute must. As soon as the temperature in it exceeds 25-28 ° C, the greenhouse must be ventilated.
As a rule, ventilation is carried out by opening the ventilation slots in the ends and roof of the greenhouse.
The area of window leaves, transoms and doors should be at least 20% of the roof area. At the same time, all the structural elements of the greenhouse should be connected as accurately as possible, and the cracks should be minimized - this will protect the plants from frost and night cooling.
About how to plan and prepare beds in the greenhouse, and the first stages of growing vegetables in the greenhouse, you will learn from our following materials.
How to choose a greenhouse in form and material and why
© Author: Vladimir Kiryushin, PhD in Biology Alexei Golubev, consultant,
Below other entries on the topic "Dacha and garden - with their own hands"
- Polycarbonate greenhouse with own hands (photo) - step by step
- Tomato seedlings in 5 liter bottles instead of a greenhouse (Tver region)
- Sowing in the greenhouse
- Simple rules for soil in the greenhouse
- Greenhouse for lazy people own hands
- Light frame greenhouse with their own hands
- Polycarbonate greenhouse for giving - pros and cons
- Soil (soil) in the greenhouse from A to Z
- Polycarbonate greenhouse with vents and growing tomatoes in it (varieties that I recommend)
- Shading the greenhouse with nets from the heat - my reviews
Subscribe to updates in our groups and share.
Let's be friends!