- Preparation of frame elements
- Installing the frame
- Greenhouse end caps and door installation
- Polycarbonate sheathing
Making a greenhouse from a shaped pipe will require you to work with metal and welding. Such a greenhouse will last for many years in all weather conditions. A greenhouse can work all year round if it is provided with heating, or starting from late February – early March, almost until the first autumn frosts.
- profile pipe 20×40 mm (20×20 mm);
- cellular polycarbonate with a minimum thickness of 6 mm;
- H-shaped docking strips;
- a set of washers for attaching polycarbonate;
- turned door sheds;
- roofing screws 19 mm;
- thermal washers for polycarbonate;
- electrodes 2.5–3 mm;
- cutting and grinding discs;
- primer three in one;
- a few bricks, concrete.
The greenhouse roof will be semicircular with low side walls. The frame is assembled by welding, and the polycarbonate is attached to the frame with self-tapping screws. The height of the structure will be 1.8 m. The arches of the greenhouse are located so that the polycarbonate sheets are joined on the arches. H-shaped strips are used to seal the joints between the sheets. The greenhouse is stationary, therefore the ends of the frame should be concreted. Using a shallow strip foundation under the entire structure, the soil inside the greenhouse is additionally isolated from the environment.
Preparation of frame elements
The greenhouse frame is made up of a series of parallel arcs of a shaped tube, as shown in the figure.
The vertical section is taken with a size of 0.5 m. 1.3 m remains at the height of the arc, this will be the rounding radius by which the length of the sector can be calculated: L = 3.14 * 1.3 = 4.1 m. Adding one meter to the result into vertical sections on both sides and 0.5 m each for deepening, get a total pipe length for each support equal to 6 m, which corresponds to the standard length, and you will not have to cut them.
Mark the material and place marks with a marker where cuts are required. Measure 0.45 m on each side – these are the buried areas in the ground. Now another 0.5 m is the vertical walls of the greenhouse.
Next, divide the remaining 4.1 m section in half. Place a mark and distribute marks from it along the entire section of the future bend in 10 cm increments.
Make cuts on the wide side of the pipe, cutting through two narrow ones. Do not cut the fourth side. The shape of the slot should be in the form of a wedge, as shown in the figure. Bend the workpiece towards the notches.
It is best to prepare a flat piece of land and distribute the pegs over it according to the shape of the future workpiece. This will make it easier to maintain the same shape for all elements of the frame..
The result should be an arc with two parallel straight pipe sections – future vertical walls. Tack weld the slots on one side, then on the other, and then completely weld and clean the seams. Weld a small piece of pipe perpendicularly to both ends of each element, which will act as a support sole.
Arcs made of profiled pipes can be bent using a pipe bender. The result will look noticeably better, increase structural strength and significantly reduce waste of time and money by eliminating most of the welding work.
Make the required number of arcs in the same way, depending on the length of the greenhouse. When making components, check their identity by overlapping each other. For all elements, it is advisable to paint half a meter from the edge on each leg to protect the metal from corrosion before further installation.
Installing the frame
In the chosen place, dig two holes 50 cm deep. At a distance from each other equal to the resulting width of the greenhouse – 2.6 m. Lay a brick at the bottom of the hole. Place the bow and fix it in an upright position, checking the position with the bubble level. Fill the pits with concrete, ramming it well with bayonet.
1. The supporting leg of the arc. 2. Brick. 3. Concrete. 4. Ground
Set the distance between the first and second support equal to 95-100 cm. Subsequent supports are located at a distance of 105 cm from each other. Between the penultimate and last support there should be the same 95-100 cm, as at the beginning. Dimensions are indicated between the midpoints of the support profile.
In order not to run constantly with a tape measure, prepare in advance several rails 101 cm long so that they can be resting against the butt between the supports.
The distances between the arcs are indicated taking into account the standard width of polycarbonate strips – 1.05 m, so that the joints fall in the middle of the profile. The width of the lintel of the H-shaped docking bar and the margin for compensating for thermal expansion are taken into account.
You can control the height of the entire structure by placing a section of a shaped pipe and a level on top of the arcs.
At a height of five centimeters from the ground, taking into account the horizontalness of the site, between the arcs, on both sides of the greenhouse, weld the lintels for rigidity. For uniform support of polycarbonate, the jumpers should also be placed at the beginning of the arc bend at the top point and in the middle between them. For these jumpers, it is easier to use a corner with 20×20 mm shelves.
Greenhouse base is ready.
Greenhouse end caps and door installation
At a height of five centimeters from the ground, weld the shelf to the arches at the end of the greenhouse, opposite to the entrance to it. At a height of one meter from the welded pipe, weld another piece. Observe the plane to fix the polycarbonate.
From the side of the entrance to the greenhouse, set, focusing on the center, two vertical pipes at a distance from each other equal to the desired width of the door, for example, 950 cm.Weld the upper edge of these racks to the arc, and concrete the bottom along the ground level.
Weld a lintel horizontally between the supports of the doorway at the desired door height. On the right and left of the doorway, fasten horizontal pipe sections at a distance of five centimeters from the ground, as well as at a height of one meter.
Make the greenhouse door from a profile pipe by welding a frame of the appropriate size. The size of the door frame is two centimeters in width less than the resulting doorway.
Select the height of the door in such a way that there is a one centimeter gap between the opening on top, and the door does not cling to the ground below. Weld a diagonal in a rectangle for rigidity.
Weld the hinged frame into the opening. Weld the metal stoppers to restrict the opening of the greenhouse door inward.
Be sure to paint all elements of the frame.
Measure the required sheet length from under the lower jumpers between the arcs, taking into account an overlap of 2-3 cm. Remove the protective film from the polycarbonate. Screw the edge of the polycarbonate sheet to the bottom lintel on one side of the greenhouse. Remember that the sheet must be screwed with the side with the protective film on the street. If the protective film is on both sides of the sheet, then pay attention to the UV markings on the sheet itself. It is necessary to fasten the sheet with the marking upwards so that the UV protection layer is outside. The film from polycarbonate can be removed after installation, but this must be done.
To attach polycarbonate to the greenhouse frame, use a special self-tapping screw with a drill on the tip, as well as heat-resistant washers for cellular polycarbonate. Washers are specially designed for this material and provide complete protection of the mount and aesthetic appearance of the structure.
At each attachment point, first, a hole is drilled in polycarbonate with a special crown or a wide drill for the corresponding size of the thermal washer sleeve. Next, a washer is inserted, drilled and a self-tapping screw is screwed into the profile pipe. At the end, the fasteners are closed with a special cap.
Start installing polycarbonate sheets from the second support and further, leveling the material strictly along the middle of the profile. Fasten the sheets last at the edges, their edges by about 5 cm will protrude beyond the extreme supports, forming a visor.
In order not to twist the material and constantly monitor its position, use quick-tightening clamps. The first sheet will require at least six clamps. All subsequent strips of polycarbonate will be held on one side by a docking bar, which will greatly facilitate the process.
An alternative to self-tapping screws and washers can be a strip of galvanized steel, which grabs at the junction sheets of cellular polycarbonate
The polycarbonate is oriented so that the internal channels are directed along the support arcs so that the condensation that forms inside can drain freely down the sides.
Trying to tightly and evenly lay the polycarbonate on the surface of the frame, screw it to the profile, gradually moving first up and then down. Distance between screws – 20-30 cm.
The docking bar has a partition and, when screwing the second sheet, you need to retreat from the first by an amount slightly greater than the thickness of this partition, to compensate for thermal expansion.
Insert the edge of the sheets into the grooves of the strip. Also measure the last sheet in width, depending on the length of the greenhouse. Leave an overlap of five centimeters.
Attach a sheet of polycarbonate to the end farthest from the entrance, mark the outline with a marker and cut out the pattern. If there is not enough sheet width, put a docking bar and add a piece of polycarbonate. Attach polycarbonate to previously welded horizontal strips and to the end of the arc.
Cover the door end surface in the same way. Pay attention that there is a gap around the edges of the door. The gap is necessary for the free movement of the door in the opening. The greenhouse is now ready.