The task, in addition, was to obtain a greenhouse with dimensions of 3 meters wide, 8 meters long, with the ability for a person of average height to move freely in it, i.e. up to 1.8 meters. Therefore, I decided to make a greenhouse from polycarbonate with a frame from a metal profile of my own design.
The frame was made mainly of lightweight metal pipes and angles. The “roof” structure was made of a ridge type, a regular gable roof, tested for reliability.The height of the ridge will vary depending on the weather conditions in your area, I chose a rafter angle of 45 degrees so that the snow rolls off easily in winter. During installation, the rafters were reinforced with a transverse beam, connected by a triangle.
Standard polycarbonate sheets have the following dimensions: thickness 4 mm, width 2.1, length 6 meters. I draw attention to the quality of polycarbonate, I used the Russian manufacturer Sunnex, let’s say it is of average quality, there is a more durable and dense material, this is noticeable in deflection, structure and weight, and ultraviolet transmission. The choice is yours, but you shouldn’t skimp in order to avoid its breaking under load from snow or wind.
Construction Traditionally, I started with laying a small foundation, since in my case the greenhouse needed to be firmly secured, and also to avoid distortions. I used thin foundation blocks and reinforced concrete sleepers. In the “standard” holes of the sleepers I placed bolts for powerful fastenings of the frame around the perimeter of the entire greenhouse. When installing the entire frame structure, welded in parts, these fasteners served as a fixation for the further installation of the upper grille (however, assistants were needed to support the frame at the moment).
Caracas made it from a 20*40 mm metal profile pipe with a grid of up to 1 meter, otherwise the polycarbonate may fail in winter due to icy snow. I made the lower ends from a 35*35 mm corner so that the door would close at the joint.
Not an unimportant point: we design the frame in such a way as to cut the polycarbonate most economically, namely, we make the side walls 1.05 meters high, taking into account cutting the sheet in half lengthwise. Rafters 2.1 meters long, so that two entire sheets can be fixed to the roof and an additional sheet can be cut into pieces of 2 meters each.
In addition to the door, I provided two windows in the greenhouse for ventilation, on the leeward side at the end and side of the structure, welded from a lightweight 20*20 mm profile. I installed the windows on piano hinges; they are quite thin and do not interfere with the polycarbonate fitting tightly to the frame.
All joints and holes in the polycarbonate were filled with silicone, and the cracks at the bottom were filled with polyurethane foam. The frame was sanded at the welding points, painted with anti-corrosion compound and paint.
Material for greenhouse construction:
- polycarbonate 2.1*6 m. – 5 sheets;
- metal profile pipe 20*40 mm – 120 meters;
- metal profile pipe 20*20 mm – 18 meters;
- self-tapping screws with a press washer and a drill – 1000 pieces;
- foundation blocks (sleepers) with a total length of 22 meters;
- sand for laying the foundation;
- fastenings and bolts for the frame;
- anti-corrosion paint;
- door and piano hinges, door handles;
- welding electrodes 3 kg.
Advantages of the greenhouse: durable gable construction; rigid fastening of the frame; required geometric dimensions; Ease of use; possibility of economical cutting of material; few joints.
Disadvantages: the junction of the roof and the side truss of the frame turned out to be reinforced with two profiles, which is not economically profitable.
