Glass greenhouses: what are and how to make yourself?
Gardening is a very topical idea against the background of the annual rise in prices for products. But the path of farmers is not easy, and there are various obstacles. A quality glass greenhouse almost completely solves the problem of temperature differences, which are reasonably considered to be a very serious problem.
Features and Purpose
The essence of any greenhouse - a cover from the weather. At the same time, unlike the greenhouse, there is no durable stationary location and / or foundation.
The use of glass for arranging greenhouses and greenhouses began in the XVII century; then in France, this structure was very expensive, and only a few of them allowed it. But mass industrial production of glass products allowed to reverse this situation in the bud.
Today in greenhouses:
- grow seedlings;
- cultivate plants derived from seeds;
- store garden tools;
- rooting cuttings;
- grow thermophilic cultures of relatively small size;
- keep queen cells;
- harden culture before the final movement into the open ground.
Advantages and disadvantages of glass greenhouses
First, consider the advantages of the design.
- Among the materials most commonly used in the greenhouse industry, glass is the most transparent. This ensures high efficiency of natural lighting. And because greenhouse owners can save on energy.
- Very good property - inertness in chemical and biological terms. Glass designs do not interest rodents and insects, at the same time they are an impenetrable barrier for hymenoptera.
- Glass does not rot, it is not subject to corrosion. Even on the hottest or coldest days, against the backdrop of drought or continuous rain, gardeners may not worry about its safety.
- Toxic chemicals and other harmful substances do not enter through glass walls.
- Excellent environmental quality, preservation of the geometric shape in any meteorological conditions, long service - these are still obvious advantages of glass.In addition, care for him is quite easy, and the ability to observe what is happening inside without opening the doors can be extremely useful.
But gardeners must take into account that glass greenhouses have serious drawbacks.
- So, it is very fragile. Careless movement with a shovel, rake or hoe, accidental fall, dull pets and birds, even just hail or snow mass can break the structure. The use of extra strong glass varieties can be considered a way out, but they are quite expensive. Worse, broken glass is dangerous to humans.
- But even when it is intact, there is reason to think. Thus, increased thermal conductivity is not always an advantage. Of course, the high efficiency of sunlight pleases the farmers until they find that fast warming up with a quick cooling down threatens plantings. And in the winter, it is very difficult to heat glass greenhouses due to significant heat loss. Double-glazed windows with two and three layers of glass partially help, additional warming structures, but the fact that all this increases costs is bad.
- Glass is heavier than other materials commonly used in the home farm. Therefore, it is necessary to prepare a solid, well-calculated foundation. This also complicates and increases the cost of work.
- Features of the retention and transmission of ultraviolet glass badly affect the development of various plants. No wonder they develop under film a little better and faster.
Selection of materials
For a long time there is no need to use sheet glass and carefully prepare the frame with your own hands. But some still do just that. By taking ready-made sheets of glass and self-inserting them into the frame, you can save a lot. Moreover, the use of used material is not reflected in the service life of the structure. Another option is the use of old wooden frames, which are relatively cheap, and in many places can be obtained for free.
A more advanced design is a greenhouse, in which aluminum elements are used along with glass. "Winged metal" is easy and good in business, well endured aggressive factors.
There are two ways to use aluminum: inserting glass into a prefab profile (you will need to equip the structurewindow leaves) or a sliding construction with the aired sidewalls. Still sometimes use plastic windows. They are much more convenient than homemade items, but they are quite expensive.
It is very rare to find a greenhouse with a metal frame. Frame this paint or use zinc-coated elements. Problems can cause the introduction of glass in such a frame. To circumvent the difficulties helps the additional creation of wooden frames, which are easily mounted on the base. Already in the frame insert glass is very easy and elegant.
Sizes and shapes
The size of glass greenhouses is determined individually. But their geometry is quite clear and is built on patterns. After all, the bend glass is expensive and an individual scheme to prepare even more expensive. The vast majority of constructions are a rectangle or a polyhedron.
A typical roof has one or two slopes, much less often use a pyramidal roof with four, five and a large number of faces.
How to make your own hands?
At home, they often try to make greenhouses of the combined type based on double-glazed windows for giving.For this purpose, a frame is formed from a bar with a section of 50x50 or 100x100 mm, after glazing of which the headband is tied. On top of this trim and mounted roof. In most cases, for the manufacture of farms used metal. For the roof take polycarbonate or organic glass.
The drawings, which are given in various sources, must be adapted to your task. After all, the dimensions are different everywhere and the conditions are different too. Therefore, blindly executing ready-made recommendations, you can face a number of problems. For those who want to simplify their work as much as possible, a wood frame is best suited. To make it as strong and accurate as possible to carry out the upcoming loads, it is advisable to take a bar of maximum section - 10x10 cm.
If it is decided to build a greenhouse with a foundation, then it is formed at ground level. But the buildings that will be operated in the winter should have a high base. It is advisable to raise it by 90-120 cm, while the opening itself (minus the frame beam) will be 80-110 cm. According to this data, it is easy to calculate the total length and width of the structure.
The glass roof should be inclined at least 15 degrees.The rafters are mainly timber with a section of 5x5 cm. The exact slope of the roof is calculated especially in all cases, taking into account the total loads from wind, snow and rain. Professionals recommend to pay attention to the calculation of the area of the vents or other air passages. The best transoms are designed with automatics that monitor the warming up of outdoor air.
Preparing a full-fledged glass greenhouse, first mark up the site in accordance with the previously drawn drawings. The upper earth layer must be removed necessarily at 30 cm in depth. Strictly within the perimeter they dig a ditch, which goes into the ground at 0.7 m. After leveling the bottom, 0.2 m of rubble is poured and the same amount of sand is compacted and covered with geological textiles. Then a special frame is made of corrugated steel rods with a cross section of 0.8-1.2 cm; the knitting wire helps to connect these rods together.
Next comes the turn of the installation of formwork, for which take wooden boards. The distance between the parallel-set walls is maintained at 30 cm, raising the edges of the sides above the surface by 10-30 cm. After that, the geometric accuracy of the design is verified, and only then all the bars are tightened.Suspension braces should be used outside, otherwise the formwork will be pressed out by the pressure of hardening concrete. The flooded solution is leveled and left in one place for a month, the subsequent completion of the basement is carried out with cement blocks or bricks.
Next, put the bottom strapping, which is tied with steel corners with a zinc layer. It is most convenient to hold these corners with self-tapping screws. After marking the perimeter racks are placed in a vertical row, and they are again fastened with similar corners. Then tie the top of the head. It is advisable to collect the truss complex on the ground, and after lifting fix it on the sled to compensate for the possible movements of the intumescent soil.
Before mounting the glass, the frame should be soaked in antiseptic formulations. Not always their capabilities are enough. But at the disposal of amateur builders there is such a powerful tool as slaked lime.
Roof along the lower tier rafters complement the bars, it is necessary to put them under the skates. You need to apply glass over the rafters, with a reserve of 0.7-1 cm, the gap is blocked by a sealant. Therefore, concerns about the leakage of the cold wind are groundless.
To enhance the protection above the layer of sealant, a plank is nailed, although some masters advise to fasten it with self-tapping screws. Then they take a galvanized sheet and cut off a strip of 20-30 cm long, which is bent longitudinally. After a thorough sealing of the joint of the glass, it is covered with such a corner set on the glue. Any internal opening is supplemented with a rail so that a peculiar frame appears. Now you can install the glass and attach it with beadings.
- To keep the glass from rattling, you need to use a silicone gasket. This is the best way to ensure pressure and at the same time eliminate the occurrence of drafts.
- Instead of buying expensive armored glass, you can simply stick on the usual transparent film. Then, even with a strong blow, you can postpone repairs for a certain period.
- It is necessary to avoid buying low-quality and rejected glass: its reliability is too low. It is advisable to study in advance the construction standards for your region.
- If you plan to grow tropical plants in winter, you should use triple glazing. Concerns about limited light transmission are in vain.Rather, the situation is reversed: sometimes the darkening turns out to be too weak. But for the cultivation of vegetables is to choose the glass, which minimally delays the luminous flux.
In some cases, using double glazing with a layer that reflects heat, you can refuse the expensive triple performance and save a little.
To learn how to build a solar vegetarian (greenhouse) from old windows, see the following video.