Nowadays, cellular polycarbonate is the main material used for the manufacturing of roof skylights, sheds and PC glazing. In some constructions and for different requirements, solid or multiwall polycarbonate sheets can also be used.
Cellular polycarbonate
Cellular polycarbonate is a great solution for minimizing the weight of a skylight, maximizing thermal parameters and keeping all the properties of polycarbonate. Cellular PC sheets are usually manufactured in dimensions of 2,1 m in width and 6 or 7 m in length, although sheets of some thicknesses come in 1,25 in width and up to 13 m in length. In the case of bigger orders, it is also possible to manufacture PC sheets of a given length.
Cellular polycarbonate consists of two or more parallel polycarbonate layers divided by a number of partitions which create hollows, or cells. The hollows run along the longer edge of the sheet, so their ends are visible from the shorter edge. The main task of the hollows is water drainage — one should bear in mind the proper arrangement of the sheet when drawing up plans for skylights. The hollows, or cells, should also be protected from dirt and insects by a self-adhesive film.
The most popular polycarbonate sheets are those of 10 mm in thickness (one, three and four layers) and 16 mm in thickness (two and five layers). Thicker PC sheets and a bigger number of layers provide better thermal insulation, slightly better elasticity and slightly worse illumination. PC sheets are perfect for barrel vault constructions due to their plastic properties. Installed within light aluminum profiles and plugged with EPDM gaskets, they are a perfect replacement for heavy and dangerous reinforced glass skylights.
Multiwall polycarbonate
In multiwall polycarbonate sheets, the edges are profiled in a way that enables to connect them without the use of aluminum profiles. They are used for polycarbonate glazing of larger areas, both vertical, horizontal or sloped and can be used for the glazing and illumination of halls or swimming pools. Multiwall PC sheets are usually manufactured in dimensions of 6 m in length, 0,5 m in width and 30-40 mm in thickness; they can have three or five layers and their heat transfer coefficient U=1,15 W/m2K.
The installation of multiwall sheeting is quite simple: only side profiles and small metal clamping bars are needed for fastening them.
Solid polycarbonate
Solid polycarbonate is extremely resistant to mechanical damage — it is almost unbreakable. It is a few times more expensive than cellular polycarbonate and has worse thermal insulation parameters, but provides a much better illumination and is a perfect solution for acoustic screens, shields or elegant awnings.
Solid polycarbonate is manufactured in sheets of 2,05 m x 3,05 m and can be transparent, opaque or brown. It can be easily cut to pieces of specified dimensions and drilled in.
UV protection
PC sheets installed on the outside of the building are inevitably exposed to solar radiation. That is why they need a UV protection layer, used as a standard by the majority of manufacturers. New polycarbonate sheets are packed in protective foil with an inscription indicating the side which should be installed on the outer side of the building, towards the sun. An incorrect installation of the sheet, i.e. upside down, might cause its quick dilapidation, so in order to avoid a mistake, we remove the protective foil after the installation is complete. It is important to remember, however, to remove it as quickly as possible to avoid its sticking to the sheet and damaging the skylight.