Cellular polycarbonate from A to Z: how to choose a quality material that will not crumble; installation tips
Having appeared not so long ago, cellular polycarbonate (SP) has become one of the most popular materials both in construction and in plant growing. Increasingly, seasonal and winter greenhouses are lined with these honeycomb sheets. In order for the joint venture not to "crumble" in one season, it must not only be chosen correctly, but also assembled according to technology.
Cellular polycarbonate and its characteristics
Cellular polycarbonate (SP) refers to polymer sheet materials characterized by a cellular structure - honeycomb cavities are formed by stiffening ribs. Sheets can be either single-chamber, consisting of two planes, or multi-chamber, with additional partitions.
- Durability - 20 times stronger than glass.
- Flexibility - the bending radius for a 10 mm panel is from 1.5 m.
- Lightness - a panel with a thickness of 10 mm, dimensions of 2100 × 6000 mm and weighs about 20 kg.
- Light transmission - up to 90% for single-chamber transparent sheets.
- Low thermal conductivity - 4.1-1.4 W / (m • ⁰С).
- Resistance to external influences - ultraviolet, wind, precipitation.
- Easy to lay on curved shapes - easily mounts on arches.
- Temperature range - from -40 to +80 ° C.
- Durability - up to 20 years.
How to identify low-quality cellular polycarbonate?
When choosing a quality joint venture, it is necessary to focus on the weight of the material. It is possible to forge certificates of conformity today, but it is unrealistic to forge weight, since it is precisely the lower consumption of polymer during molding that causes both the low cost price and lower strength. For comparison, a sheet of joint venture with a thickness of 3-4 mm, produced according to GOST, will weigh about 800 g / m²; the standard is somewhat lighter - approximately 600-700 g / m². Economy, not to mention a complete samopal, lighter than anywhere else, there are sheets of 300 g / m². There are no miracles in the world and you should not expect from a light sheet of high strength.
How to check the strength of the joint venture by touch?
You can quickly and accurately determine the quality of polycarbonate by simple pressure - the sheet must be squeezed with your fingers. On a high-quality, dense material, no traces will remain from such probing, but a "weak" sheet may well deform - a dent will remain, up to broken partitions.
Why do greenhouses need transparent cellular polycarbonate??
When it comes to gazebos, pergolas, terraces and other awnings, nowadays increasingly covered with cellular polycarbonate, colored varieties are preferable. They not only look more presentable, but also less translucent. If we are talking about a greenhouse, in which the plants should feel comfortable, then the coating should be transparent. Any shades automatically reduce the amount of light entering the greenhouse, which negatively affects the plants.
How to install the cladding correctly?
- The sheets are mounted upward with the side with a protective colored film with markings. It is not worth removing the film before installation, but immediately after it is necessary. Otherwise it can happen as with plastic windows, when the protection "sticks" to the base.
- The honeycombs in the sheets should be located parallel to the arcs or frame elements so that moisture condensing in the honeycomb flows down and out through them without hindrance.
- When assembling, it is advisable to use specialized extensions - connecting, ridge, end, corner profiles.
- Holes for fasteners are drilled between the stiffening ribs, at a distance of at least 40 mm from the edge of the sheet.
- The panels are fixed to the frame with self-tapping screws with wide gaskets, the diameter of the self-tapping screw should be several mm less than the drilled hole.
- The upper ends of the sheet are closed with an impermeable tape, and the lower ones, perforated, so as not to lock moisture inside the honeycomb. Holes are also drilled in the end profiles, which additionally protect the panels, to drain the condensate.
What is the best sheet thickness for a greenhouse?
One of the most important parameters when choosing a cladding for a greenhouse is the thickness of the honeycomb polycarbonate sheets. If we take too thin, they, firstly, are less resistant to stress, and secondly, they will keep heat worse. Excessively thick, this is a significant increase in the budget, and difficulties with fasteners and extensions, and less flexibility. The optimal panel thickness is selected based on the specifics of the greenhouse.
- Seasonal - 4–6 mm (if the weather does not abound in large hailstones, the lower limit is sufficient, in unfavorable conditions it is better to play it safe and put thicker).
- Winter - installation of a two-layer shell, where the lower layer is 4–6 mm thick, and the upper one is 10–16 mm (20 mm in Siberia).
To a greater extent, the strength of the material is influenced not so much by the thickness as by the quality. If the products of responsible manufacturers (GOST, standard) correspond to the declared characteristics, then sheets with a rank worse than criticism do not stand up to criticism. That is, with the same thickness, say, 6 mm, panels made according to GOST will calmly withstand snow, wind and hail, and those that cost very little will become unusable after the first season.
If you are using cellular polycarbonate - support it like!
Read also: How to choose and use cellular polycarbonate in the construction of sheds, greenhouses, winter gardens and canopies of country houses.
Watch the video: How to make an insulated greenhouse in harsh conditions.