To create interfloor ceilings during the construction of private houses and multi-storey buildings, panel constructions are used. They have different technical parameters, operational properties and installation capabilities, which ultimately determine the purpose of a particular product. There are also universal requirements for floor panels, which boil down to optimal mechanical strength, heat and noise insulation, durability, etc.
Panel Materials
The production uses concrete, metal, stone, brick and wood, as well as combinations of these materials. More often concrete is used as a structural basis in various designs. Stone and brick floors are used in individual construction and are considered the most wear-resistant filling for the shape of this structure. However, for the manufacture of such ceilings, special expensive technologies are used, so they are used less often. Usually, on this basis, small-sized wall panels are made. For horizontal structures, concrete with elements of metal reinforcement is mainly used. A group of panels is largely formed by lumber or wood-based waste. Solid wood is used for floor beams, and thin sheets act as a means of external cladding, covering themselves with insulating material laid in empty niches.
Panel structure
Concrete elements are usually made on a monolithic or prefabricated basis, but the structure in both cases is formed by cement-sand mixtures reinforced with metal rods. It turns out a reinforced concrete slab, which may include additional functional devices. Sandwich panels are made of wood material, which usually consist of several layers. Again, each layer can be made from solid billets or wood-based raw materials. In some models, the core is filled with an insulating material - insulation, waterproof or noise-canceling layer.
SIP Panel Features
Overlapping of this material was originally used in frame houses made according to Canadian technology. But their technical and operational advantages have expanded the scope. After optimization and adaptation to Russian conditions, SIP-panel technology has become popular in the segment of individual construction.
Today, such structures are made of a joining beam, which before processing passes chamber drying to humidity with a coefficient of 12%. According to the structure of the overlap of SIP panels, they are an insulating sheet, including a heat-insulating layer and two protective OSB coatings on both sides. The joints are made using polyurethane adhesive, which is pressed in the factory under a pressure of about 20 tons. Various variations of SIP panels also appear, which are made from wood-chip layers, chipboard and thermal insulation polystyrene.
Actually, the main operational advantages of such ceilings remain unchanged - effective thermal insulation, thermal barrier, ease of installation and low price. The disadvantages of SIP panels are expressed in flammability, exposure to biological damage and environmental hazards. The last negative factor is due to chemically unsafe binders like the same polyurethane. Conversely, protection against fire, fungus and mold is enhanced by the use of special impregnations for wood.
CLT Panel Features
Another, but more modern kind of wood-based multilayer panels, which is used both in the private and in the industrial sector. This is a structural element obtained in the process of cross-gluing solid wood slats also under a multi-ton press. Such slabs are closer to reinforced concrete floors in terms of strength and durability than SIP panels. But in addition to structural reliability, this material has many positive qualities - more precisely, combinations of operational properties. For example, the technical stability of the CLT floor panel is organically combined with protection against thermal influences and the influence of aggressive chemical environments. There are other advantages over hard concrete slabs. In particular, the flexibility of the lamella structure allows them to withstand both static and dynamic loads, which is especially important for regions with seismic activity.
Types of reinforced concrete panels
The traditional segment of concrete floors is also not limited to typical options. To date, the following types of floors of this class are used:
- Frequently ribbed. They are optimally suited for buildings with a large area where conventional concrete structures can bend. Stiffeners eliminate the risk of deformation.
- Monolithic. The element is quite difficult to manufacture and install, but it also gives more structural possibilities for the installation of interfloor partitions. For example, reinforced concrete floor panels with a monolithic structure can be installed in rooms without a single load-bearing wall.
- National teams. The basis can be laid both often-ribbed and standard monolithic segments of reinforced concrete slabs, and the feature will be precisely in their combination. The overlap can be formed in separate parts, both through reinforcing ligaments by welding, and by the technology of cement-sand joints.
Technical and operational characteristics
The parameters of the floors are approved by SNiP standards. So, with a thickness of insulation of 100 mm, the heat transfer resistance should be 2.8 W / (m ° C). If panels with a standard thickness of 224 mm are used, then the value of thermal resistance will already be 5.2 W / (m ° C). The optimal parameters of insulation and resistance to various microclimatic influences are achieved due to the material of the middle layer. As a rule, in multilayer constructions a heater based on mineral wool or polystyrene foam is used.
Ranges according to the size of the floor panels can be represented as follows: thickness is from 60 to 250 mm, length is from 900 to 3600 mm, and width is from 600 to 2500 mm on average. The mass index is also very important in the calculations. Depending on the materials of execution of the floor, the weight of 1 m 2 of the structure can vary from 220 to 450 kg. Again, we are talking about averaged normative values, but the standards, depending on the operating conditions of the structure, also allow going beyond these limits.
Panel Reinforcement
Wooden products in the traditional sense of this reinforcement technology are not reinforced. After installation, they can be strengthened with screeds, bandages or metal clamps with stiffeners, but the rods are not inserted into the structure itself. In reinforced concrete floors, thermomechanically hardened reinforcing steel of various types is used. It enhances structural strength and durability. There are also multi-hollow floor panels without reinforcement. Cylindrical voids with a diameter of 60-90 mm in themselves add mechanical resistance to the product, performing a function similar to the same stiffening ribs. Another plus of free niches in the structure of reinforced concrete floors is a reduction in mass.
Mounting technology
Reinforced concrete slabs and wooden panels are mounted in different ways. The first are installed with a crane on the prepared area with cement-sand mortar on the walls. Bearing supports are completely covered by a continuous construction platform without gaps. Crane operators, slingers, as well as a group of assistant workers participate in the work. It is easier to install floor panels, implemented by the groove joint system with the inclusion of self-tapping screws. For such structures, I-beams are pre-installed with profile grooves into which the ceilings are inserted. Then, using self-tapping screws, the structure is finally fixed in the technological niche.
Pros and cons of panel structures for overlapping
Among the advantages of wood panels, many note the low cost, ease of installation and resistance to dynamic loads. Although such structures lose strength and stiffness to reinforced concrete, in seismically hazardous areas, the flexibility of wood-based materials is a very valuable characteristic. If we talk about the shortcomings, then the floor panels of this type are very sensitive to fire and biological damage. Of course, technologists also calculate such nuances, appropriately processing the structure of the material. But even during operation, the user himself will have to regularly monitor the state of the structure, performing procedures for its comprehensive protection by special means.
Panel Applications
The target objects for using this design are wooden buildings. Initially, panel multilayer ceilings were introduced into prefabricated house kits, but today they are also used in traditional buildings from glued beams, and not only. Slag and aerated concrete houses with small frame loads can also be constructed using wooden floor panels. Concrete slabs just turn out to be an undesirable solution due to their high weight, and, for example, dense CLT lamellas will suit the builder both in terms of rigidity and weight. Use this material in the laying of foundation sites, forming the supporting base for small outbuildings.
Conclusion
It cannot be said that new technologies for the installation of ceilings displace the methods of their traditional device with reinforced concrete structures. Nevertheless, the capital construction of multi-storey buildings and large industrial facilities has not yet considered wooden floor panels as a complete replacement for conventional solid-state plates. But in the private segment, the transition to prefabricated frame structures naturally determines the use of the same SIP elements. They not only meet the requirements of individual suburban housing construction, but also organically fit into the concept of ecological houses, albeit with some nuances. Another thing is that there is also a technology for the installation of beam ceilings, which also has many advantages of installing wooden panels, making them a serious competitor.