The advent of sandwich panels made it possible to construct buildings very quickly. Today, thanks to wall and roof panels, not only warehouses, pavilions, terminals and other industrial structures are erected, but also private houses. Such wide distribution of sandwich panels owe a lot of advantages: speed and ease of installation, lightness of construction, aesthetics and economy of material, excellent heat and sound insulation qualities. The constantly growing demand for the material has led to an increase in the assortment, and today, without preparation, you can only decide on the color, and more than 600 shades are presented. But here’s how to choose a sandwich panel with the right type of insulation, suitable thickness and profile?
# 1. Sandwich panel production technology
A sandwich panel is a multi-layer material consisting of a layer of insulation, covered on both sides with metal or PVC. Its quality depends not only on the raw materials used, but also on the method of production. At the moment, sandwich panels are produced in the following ways:
assembly from individual elements in the immediate vicinity of the construction site, where steel sheets, insulation and glue are brought. The process is convenient, but as a result, panels with not the best performance are obtained;
the foaming method consists in filling the cavity between two sheets of steel with polyurethane foam, which is foamed under pressure. If the insulation comes unevenly, but cavities will form that violate the thermal insulation;
the conveyor method is the most perfect and thorough, it allows you to create sandwich panels with the best performance. When choosing, you should pay attention to products manufactured in this way. There are not so many domestic companies working on this technology, one of these is Nelidovsky roofing plant.
# 2. Cladding material type
Sheets of steel, plastic, drywall or OSB panels can be used as facing material. Naturally, metal sheets are the most durable, their thickness varies from 0.5 to 0.7 mm, and performance largely depends on the type and thickness of the anti-corrosion coating. Usually steel sheets are galvanized, and the thicker the zinc layer, the more durable the panels will be. Alternatively, a zinc-alumina (galvalum) coating is used, which has been specially developed to protect sandwich panels and is highly resistant to atmospheric moisture and sunlight.
A coating of galfan (an alloy of zinc, aluminum, lanthanum and cerium) is also used, which, with a smaller thickness, surpasses the zinc coating in ductility and resistance to mechanical damage. Often the panels are also coated with polymer over a layer of protective alloy. Thus, an improvement in resistance to weathering is achieved.
Drywall allows you to get lighter sandwich panels, but they can only be used for installing internal partitions. OSB panels (oriented strand boards) are the basis of SIP panels, which also include expanded polystyrene insulation. The structural features of OSB boards allow you to securely hold fasteners, thereby increasing the strength of the finished structure. Such sandwich panels are used to equip floors, walls and roofs.
No. 3. Insulation type
The insulation layer can vary in thickness from 5 to 30 cm, moreover, sandwich panels with a thickness of more than 15 cm are used mainly for arranging refrigerating chambers. Materials such as the following can be used as insulation:
They all differ in a certain set of advantages and disadvantages. So, mineral wool does not support combustion and is environmentally friendly; rodents will not live in such insulation. Of the minuses, it is worth highlighting hygroscopicity, therefore, the tightness of the finished structure must be given great attention, because when moisture is absorbed, the thermal insulation properties deteriorate. Nevertheless, it is mineral wool that is most often used today by domestic manufacturers in the manufacture of sandwich panels.
Polystyrene is a durable moisture-proof material with high thermal insulation properties. It is exposed to the negative effects of sunlight, but thanks to the sheathing with steel sheets, this disadvantage can be avoided. Polystyrene burns easily, releasing toxic substances; rodents can live in it.
Polyurethane foam is in great demand in a number of European countries, as it has a minimum of disadvantages with a huge number of advantages, for which it is so loved in European countries. Among the advantages of the material, it is worth highlighting resistance to moisture: even if water seeps out to the insulation, it will not cause any negative consequences. This type of insulation is very light, which simplifies the transportation of panels, their installation, and reduces the load on the foundation. The main advantage is low thermal conductivity, 2 times lower than that of mineral wool, and 1.5 times lower than that of polystyrene. Polyisocyanurate, a type of polyurethane foam, has self-extinguishing properties, and it is today that it is increasingly used as a heater for sandwich panels. In addition, the insulation will not become a place for the development of fungus and mold. Among the disadvantages is the possibility of damage by rodents.
No. 4. What is the difference between roofing and wall sandwich panels?
The basic principle of the construction of wall and roof sandwich panels is the same, but there are still some differences in the design that make it preferable to use some panels for the construction of walls, and others for roofs.
The first difference is in the profile of the steel sheet. For the construction of walls, smooth sheets or profiled under a log, siding, microwaves are used. The roof panels are high profile for greater strength and stability so that the roof can handle heavy snow loads in winter. Steel sheets can be profiled on both sides for even greater stability. In addition, higher density insulation is used for roofing panels.
Another difference is the type of lock used to connect the panels. Roof sandwich panels are characterized by a more complex lock, which is necessary in order to overcome the pressure of the atmosphere and precipitation. Also, roofing panels have an even thicker anti-corrosion layer than wall panels.
No. 5. Required parameters of sandwich panels
For the construction of walls, sandwich panels with a width of 1.1 and 1.5 m are used, but the length can vary widely – from 2 to 18.5 m, so that you can easily and simply build a building with any necessary parameters. As a rule, the width of roofing sandwich panels is 1 m, the length is from 1 to 16 m. In addition, it is important to remember that when installing roofing panels, you must adhere to a slope of 7 degrees.
If everything is more or less clear with the length and width, and their choice depends on the parameters of the building that needs to be built, then the selection of the thickness of the panels is a more responsible process. This parameter is calculated on the basis of a heat engineering calculation: it is laborious, but not the most difficult, and requires many factors to be taken into account. The calculation method is easy to find on the Internet, and even easier – to use a special calculation calculator or seek help from specialists.
When choosing a panel thickness, it is necessary to take into account the purpose of the building, the planned internal temperature, the climatic features of the region, the coefficient of thermal conductivity, etc. For example, if a building is located in the Moscow region, and the temperature inside it is planned at + 180C, then the thickness of wall panels with mineral wool insulation should be 15 cm, with foam polystyrene insulation – 12 cm.Under similar conditions, the thickness of roofing sandwich panels with mineral wool insulation will be 25 cm, with expanded polystyrene insulation – 18 cm.
When choosing the required thickness, it is also important to take into account the cost of heating the room. So, with a thicker panels, heating costs will decrease, but construction will also cost more, but these expenses will pay off in the first 2-3 heating seasons.
No. 6. Appearance of sandwich panels
Among the more than 600 shades available in the manufacture of sandwich panels, everyone can choose the one that best meets the requirements. Moreover, in addition to material with a smooth surface, today there are panels with a rough texture that imitate the surface of wood or stone, and this brings the appearance of buildings built in this way to a new level. As for the geometry of the panels, specialists will be able to select the required height and shape of the ridges and other elements, taking into account the gaps, outlets, undercuts, abutments of the sandwich panels.