The domed greenhouse (or, as it is also called, geodesic) is one of the most spectacular structures that are being built at their summer cottage. Such a structure is made in the form of a hemisphere, and the frame is assembled from triangular segments. In addition to the external attractive appearance, such greenhouses have a number of operational advantages and are the most profitable for growing plants throughout the year.
Advantages of dome greenhouses
Dome greenhouse has the following advantages:
- Greenhouses of a round shape are distinguished by the highest strength and stability, far exceeding the usual, familiar types. The streamlined design with a wide base allows it to withstand strong storm winds.
- The advantage of such structures is high seismic resistance. It is provided by a sectional type of construction, which evenly distributes the forces acting on it and significantly weakens them.
- An important advantage of domed greenhouses is the ability to keep indoor temperatures favorable for plants for a long time withoutadditional heating. This effect is provided due to the spherical shape of the structure. During the day, the air warms up, rises and fills the entire dome space. At night, it is displaced by a cold current, which directs warm air down to the plants. During the day, the sun through the transparent roof and walls again heats the soil, which, in turn, transfers heat to the air. Thus, air circulation occurs, providing a favorable microclimate inside the greenhouse.
- There is never a shortage of light inside the domed greenhouse, as the sun's rays freely penetrate it from all directions.
- The domed shape saves up to 30% of interior space.
- The domed greenhouse is very mobile, as it consists of triangles that can be easily assembled and disassembled. The main thing is to make sure that the length of all elements is the same.
- Economic benefit: the consumption of protective material is the lowest among greenhouses.
- The domed greenhouse (photo attached) has a beautiful and decorative appearance - in fact, it is a decoration of the site.
- One of the main disadvantages of dome structures is their limited size. It is impossible to place many beds inside such a greenhouse and it is not very convenient to work, since it is almost impossible to stand up in it to its full height. This problem can be solved by increasing one of its main parameters - the diameter.
Flaws
- It will not be possible to growtall plants, so the domed greenhouse is not functional enough.
- The complexity of shelving on the flat and rounded walls of the dome.
- The design of such greenhouses is very complex. Performing calculations and assembling it with your own hands is not so simple (but possible). It consists of polygonal and triangular frames, which are not always possible to make at home, so they have to be ordered somewhere on the side, and this leads to an increase in the cost of the entire structure. In this case, you can use the assembly of ready-made domed greenhouses. Their frame consists of metal profiles and is very quick and easy to assemble.
Now let's move on to the most important thing - the creation of such structures. First of all, it should be noted that a domed greenhouse can be made from plastic pipes, metal profiles, wooden bars, etc., that is, from any materials at hand.
Building domed greenhouses with your own hands
Despite the complexity of the design, it is quite possible to make domed greenhouses with your own hands. It is important to understand that, in general, the design consists of a network of triangles that are connected to each other at a certain angle and in a certain order. A greenhouse with a massive dome, despite its large bearing capacity, must have additional supports along the perimeter of the frame - load-bearing beams.
Polycarbonate dome greenhouse
Such designs are considered the mostin demand, because this material is more durable than polyethylene. It is extremely irrational to use glass for sealing greenhouses of this type due to its high cost and heavy weight. However, this material wins in terms of durability and transparency.
Materials and tools for building a domed greenhouse
For construction you will need:
- Wooden bars or metal beams of the same length.
- Polycarbonate or other protective material (polyethylene, glass).
- Connecting elements needed to assemble the frame (self-tapping screws, steel strips, washers, screws).
- Roulette, level, shovel.
- Shiny material for covering the north dome (such as foil).
Dome greenhouse: step-by-step calculation
The main task in calculating the dome is to obtain the following data for a given radius:
- total area and height of the structure;
- dome surface area;
- length and number of ribs;
- value of intercostal angles;
- type and number of connectors.
To calculate the dome, you must first determine the size of the future structure. It should be taken into account that the base area of the finished product will be less than the area of the circle, since the base contains a polyhedron inscribed in a given circle.
The height of the dome is determined by the length of its diameter. It can be:
- for even heightsplits 1\2, 1\4, 1/6 diameter;
- for odd - 3/8, 5/8.
The higher the greenhouse, the more the structure will resemble a ball.
The surface area of the structure is calculated using the following formula: S=4 π R2.
For a dome that is half a sphere, use the formula S=2 π R2. If it is necessary to calculate the area of a segment of a sphere, use the formula S=2 π RH, where H is the height of the segment.
To calculate the necessary structural elements, you can use the online calculator. It is enough to enter data on the height and radius of the dome, and the service will calculate, give the number and length of the ribs, the number and type of connectors.
The length of the ribs can be calculated independently using coefficients, and it is better to entrust the calculation of the amount of materials to the calculator.
The best option for a domed polycarbonate greenhouse - the height is 1/2 of the diameter. This hemisphere is the easiest to assemble and easy to use. According to the calculations of the geodetic calculator, to assemble a structure 2 m high and 4 m in diameter, you will need:
- 35 triangular-shaped elements, the edge length of which is 1.23 m;
- 30 elements with an edge length of 1.09 m.
The calculator offers a color scheme, according to which it is very convenient to assemble the dome.
Preparation of materials
According to the data received, material for construction is being produced. As connecting elements, it is better to choose a galvanized material that is resistant to corrosion. Particular attention should be paid to the accuracysizes of all parts.
After the blanks of the bars are ready, cut strips of steel 2 mm thick. Seven holes for self-tapping screws are drilled in them at the same distance from each other.
Assembling the frame
When assembling a spherical structure, 3 types of connecting nodes are used:
- 4-corner elements, in which the long sides correspond to the length of the frame ribs, and the short ones correspond to the height of the base of the greenhouse;
- 5-angled - this is the main part of the geodesic dome. Collect them from triangular elements;
- 6-angle elements.
Strips of steel are bent at an angle of 250° so that 3 holes remain on one side and 4 on the other.
Stages of frame assembly:
Do-it-yourself polycarbonate dome greenhouse is assembled as follows:
- The place for the greenhouse is being prepared, marking is being done. The site is leveled and covered with geotextiles to prevent the germination of weeds. Gravel filling is being done.
- The base of the domed greenhouse is installed, consisting of quadrangular elements. Each of them is fixed on the ground with metal arcs or staples.
- According to the color scheme given by the geodetic calculator, pentagonal elements are assembled from triangular elements. The assembly is carried out in this way: first, the elements of the lower tier are connected in a circle, and then they move on to the upper one.
- Several vents are made at the top of the frame.
- For greenhouse claddingfrom polycarbonate, preliminary preparation of the material is needed - cutting into triangles of appropriate sizes.
Arrangement of the inside of the domed greenhouse
From the north side, the inner space of the hemisphere is pasted over with foil material. A water container is installed in the center of the greenhouse, which can be used to water the plants.
If the greenhouse is designed for year-round operation, pipes of the heating system are laid along its walls. A conventional electric fan is used to circulate the air in the room.
The beds, if desired, can be arranged in several tiers. The optimal passage width is 1-1.5 m.
Instead of a container with water in the center of the hemisphere, you can place a beautiful exotic tree, and set a table with chairs against the wall. Thus, the domed greenhouse will turn into a very cozy place to relax, which reliably protects from bad weather.
