Ventilated facade technology has been successfully used in construction for many years. Among the target objects are business centers, railway terminals, entertainment complexes and other buildings with high aesthetic and functional requirements for exterior decoration. A new stage in the development of ventilated finishing technology has become a cassette facade, the photo of which is presented below. This technology greatly simplified the configuration of the formation of a multilayer cladding, slightly changing the rules for its installation.
Technology Features
The basic arrangement of a ventilated facade involves the use of three main elements - a supporting profile (metal lathing), insulation and outer skin. Slabs are usually used as the last component.porcelain stoneware, corresponding to the overall design of the building. The installation of such a system is carried out manually in stages, which requires careful technological calculation. This approach has been corrected by cassette metal panels. For facades of this type, functional frame-sheathing slabs are used, which perform not only an external decorative role, but also fastening and fixing tasks.
If a porcelain stoneware panel is absolutely devoid of any elements for installation and an individual base for fastening must be developed for it, then metal structures are maximally optimized for connection with the base profile frame. But for fastening to the wall and crate, sets with anchor bolts, butt elements and bearing clamps are also used. Of course, the central part also retains its functionality, allowing the space to be filled with thermal insulation materials, hydro and noise barriers.
Cassette Specifications
Panels are necessarily produced from metal with anti-corrosion coating. The thickness of the sheets is small and averages from 0.7 to 1.5 mm. A technological gap of 40 to 100 mm is maintained between the wall and the sheathing. Layout parameters will largely be determined by the type of structure and the height of the building. For example, for objects up to 40 m high, a standard cassette facade is used, the dimensions of the panels of which can be as follows:
- For bearing and guiding profiles (vertical and horizontal) - 60x27x1 mm.
- For supporting profiles(vertical) - 75x20x0.7 mm.
For buildings over 40 m high, panels of the following formats are used:
- Bearing and guiding profiles (horizontal and vertical) - 60x27x1.5 mm.
- Bearing profiles (vertical) - 75x20x1 mm.
In some cases, additional leveling brackets are used, from 125 to 250 mm long and 1 mm thick.
The function of insulation is usually performed by mineral wool with a density of up to 100 kg / m3 and a thickness of 100-150 mm. By the way, laying can be done in two layers. If the calculation of conventional ventilated facades can cause restrictions in the depth of the structure due to the thickness of porcelain stoneware panels (15-20 mm), then sheet metal sheathing provides additional space for technological niche filling. The fastening of the heat insulator is carried out using a dish-shaped glass-polyamide dowel, which minimizes possible gaps between the base and the mounted plate.
Classification of cassette facades by guides
Sheathing elements may assume a different installation configuration - vertical or horizontal. From the point of view of the ventilation facade concept, this is the basic structure, which is formed by panels fixed with galvanized steel rivets. Particular attention is paid to gaps, seams and all kinds of joints between the cladding components and the fixing parts of the cassette facade. The design device technology provides for the preservation of space to compensate for temperature deformations, therefore they are not completely sealed. In other words,some layers of a structure, like an insulator, can expand under conditions of increasing temperature, and in order to avoid deformations, a technological gap of about 10 mm is left. More importantly, the vertical guides do not have attachment points to each other.
The horizontal rail system is used less often and usually as a supplement to the vertical structure. Fastening is realized using the same additional elements in the form of rivets. The most important node in such a cassette facade is the convergence nodes of horizontal and vertical guides. It is recommended to use the “overlapping” technique, which may require trimming of the side contours. Directly mechanical hitch is also made with galvanized rivets. Thin metal allows, in particular, the use of hardware format 3, 2x8 mm.
Classification by type of load-bearing members
Guides can be duplicated by a supporting structure, but this is not necessary. In this case, the division is based on the number of levels. That is, both in the layout of vertical / horizontal systems, a combined two-layer version can be implemented, and when installing a carrier base, both a single-level and a two-level configuration are mounted.
The simplest systems are based on a vertical single-level supporting structure. Decorative inserts made of the same material that was used in the manufacture of metal cassettes are superimposed on the visible area of the profile. The facade, by the way, can be sheathed not onlyanti-corrosion galvanized steel alloys (the most reliable option). In some cases, copper and aluminum are used.
As for the two-level carrier system, U-shaped profile elements are additionally superimposed on the vertical base. If oblong cassettes longer than 700 mm are used, then an auxiliary PS-shaped profile in the central area of the cassettes can also be included.
Types of cassettes
Metal panels also differ - in terms of mounting methods, finishes, textured and textural qualities, etc. For example, the most affordable elements have a flat surface, are made of anodized thin aluminum and are provided with typical groove nodes for fixing. In more complex versions, cassette facades are formed from rectangular steel plates, the outer side of which can have various patterns and even 3D visualization tools. In terms of technical and structural device, the variety is small. Most panels have perforated areas at the edges for fixing to the base with hidden hardware. The side mounting method is considered the standard, although there are also installation methods using universal additional fittings - that is, installation is carried out by means of a transitional profile lining that connects the panel to the crate. However, the installation technique deserves a separate discussion.
Installation of the structure
Work activities are carried out according to a previously prepared project with a technical solution. Further workcarried out in the following order:
- Material is being prepared with mounting hardware and consumables. The integrity of the elements is checked, their compliance with the design requirements and the terms of reference.
- The base for the cassette facade is being installed - the installation of guides and profile elements that will form the supporting base.
- Laying insulating material.
- Installing panel cassettes.
Initially, the flatness of the target surface is checked using a theodolite, level or plumb line. Next, points are marked for installing leveling brackets. The installation of the initial strips is carried out, a system of vertical guides is formed, on the basis of which the panels will stand. The insulation is fixed with a special fixing dowel, and in the future its position will be controlled by intermediate guides from the crate system. It is enough to lay the same mineral wool in the prepared niche without rigid fixation.
Panels are fastened in the direction from bottom to top and from left to right. Particular attention is paid to the installation of the cassette facade in the lower corners. Here, ebbs are used, which perform the functions of supporting and corrective additional elements in relation to the entire cassette field. The starting strips at the bottom can also adjust the position of the panel rows. In case of deviations, a small space of temperature gaps can be used to compensate. The mounting edges of the cassettes overlap and are closed with mounting hardware -bolts, dowels or screws. The choice of hardware will depend on the characteristics of the crate and the material of the base to which the fasteners are made.
Facade operation rules
After installation work, a control check of the quality of fastening, ventilation systems and the integrity of the skin is carried out. In the future, it is recommended to observe the following rules for the operation of cassette ventilated facades:
- It is not allowed to attach equipment and third-party mounting elements to the cladding.
- The risks of water getting from the roofing into the niche of the facade are excluded. For drainage, special trays and drains are provided in a separate order.
- About every 4 years, scheduled inspections of the facade structure are organized. In particular, the cladding elements, the condition of thermal insulation and fasteners are checked. Moreover, control and verification activities should be trusted to specialized firms with the appropriate license.
- For residential high-rise buildings from 75 m and public buildings from 50 m, regular monitoring of the condition of the cladding is required.
Features of caring for a cassette-type facade
The surfaces of metal panels do not require special care in terms of maintaining technical and physical properties. The material is initially designed for harsh conditions of use in contact with atmospheric precipitation, wind loads, etc. However, in order to maintain an aesthetically attractive surface of the cassette panels for the facade, it is recommended to periodically washbrushes by hand. Coarse-grained abrasives should be discarded. As cleaning and washing chemicals, you can use ordinary soap or specialized non-aggressive products for metal coatings. Moreover, during care, it is important to ensure that the liquid does not penetrate into the ventilated space - contact with water is detrimental to thermal insulation.
Technology reviews
The concept of a ventilated façade, as such, deserves a mostly positive user experience. If the design advantages of the structure can be appreciated by every visitor of a building with such a cladding, then the direct owners praise its technical and functional advantages. These include the same undemanding maintenance, ensuring an optimal microclimate in the premises, maintaining the dryness of the walls and, in principle, protecting the base of the supporting frame. It is due to the possibility of air circulation that the walls are ventilated and condensate with unwanted moisture is removed.
Of course, there are disadvantages. They are usually associated with the complexity of installation work and unpleasant consequences already during operation. In particular, the smallest errors in the assembly of the cassette facade lead to the appearance of a hum and whistle. This is how improper air circulation with interference in the structure makes itself felt. Not all developers decide to use such cladding and because of the high cost. The usual one-layer finish, regardless of the material, will cost less and many are ready to give up the functional advantages of the ventilated facade as such. Otherthe fact is that the replacement of porcelain stoneware with metal panels, in addition to facilitating installation work, nevertheless made it possible to reduce the cost of the structure as a whole.
Conclusion
Problems of using new construction technologies in Russia are often caused by low qualification of their performers and unsatisfactory quality of building materials. In part, this also applies to the technology under consideration, so it is initially important to contact trusted companies whose specialists understand the smallest technical subtleties of using cassette facades. The manufacturers of the first link, in particular, include the enterprises Alga, INSI, Armaks, etc. Their main advantage is the use of products from leading developers of ventilated facades as components. In particular, Finnish-made Ruukki cassettes (Liberta series) are widely used. This line is distinguished by both design and technical and structural advantages. The cost is also acceptable, although we should not forget about other components of the ventilated facade. Thermal insulation and fasteners are also important.
