Time dictates its conditions, presenting new requirements, both to the aesthetic and technical solutions of the facades of buildings. The main directions of development of enclosing structures is an orientation towards the use of energy-saving, durable materials and technologies that allow you to quickly and conveniently carry out the necessary work in a short time. Structures that combine these requirements include ventilated facade systems.
Today ventilated facades are one of the most demanded facade structures. The company "TATPROF" offers ventilated facades designs with its own technological solutions, fully focused on the modern Russian market, therefore, objects with such facades can be seen in many cities of Russia and neighboring countries.
Such a success of the TATPROF system has led to the competent design of profile systems for different types of facade materials and surface shapes, compliance with GOSTs and strict technical production requirements, as well as the joint work of the profile manufacturer, the facade structure itself (converters), construction and installation work manufacturers and design and architectural bureaus in the implementation of unique projects that have not been built in Russia before (a vivid example is the "Olympic Stadium SOCHI 2014" Big Ice Arena "where the entire surface of the enclosing structures of the facade - the roof is assembled from a profile)
Let's figure out what makes up the algorithm for the success of the application (and choice by the Customer) of TATPROF facade systems at facilities throughout Russia.
Basic concepts.
Currently, more than 20 types of hinged facade systems are recommended for use on the territory of the Russian Federation. Modern hinged facade systems with an air gap represent a layer of thermal insulation, a metal substructure (frame), a decorative screen (cladding) installed at a distance from the thermal insulation layer.
The material and thickness of the insulation are selected according to the heat engineering calculation. At the same time, a layer of thermal insulation is not an obligatory element of the LFS in the event that the heat-shielding properties of the outer fence are provided by the mass of the main wall and the curtain facade is used for architectural and decorative purposes.
The metal substructure includes brackets and guides, perceives and redistributes loads from the decorative screen and transfers them to the main structures of the frame of a building or structure.
The decorative screen (cladding) performs architectural functions and protects the thermal insulation layer and the supporting structures of the building from atmospheric influences. For the device of a protective and decorative screen (cladding), plates, panels, cassettes or sheet materials with visible or hidden fastening are used:
- ceramic;
- from porcelain stoneware;
- made of natural stone;
- fiber cement (including asbestos cement);
- made of metal, composite or aluminum materials.
General principles of design
As with any building structure, a design stage is required before installing a curtain ventilated facade. Design documentation for each specific building with a ventilated facade is developed on the basis of a design assignment, which is approved by the customer.
The design assignment should include the following initial data:
- architectural drawings of the facades of the building, including data on the texture and color of facing materials, drawings of architectural details (cornices, framing of openings, etc.);
- working drawings of external walls, including nodes;
- data from the developers of foundations on the value of the permissible additional load on the walls of the building;
- plan of the site where the building is located.
The design assignment must be completed with a Technical Certificate with the appendices: "Technical assessment of the suitability of products in construction" and "Album of technical solutions".
The design of a ventilation facade begins with the placement of guides and brackets on the facade of the building relative to the existing openings. The minimum permissible distance from the axis of the anchor bolt (or dowel) to the edge of the stone structure (outer corner, window slope, etc.) must be at least 100 mm. The minimum depth of anchoring into concrete is 50 mm; in brick - 80 mm; in lightweight concrete - 100 mm. The building system "TATPROF" provides 3 options for fixing the brackets of the ventilation facades to the supporting base: only to the walls; to walls and ceilings; only to interfloor ceilings (if the wall material has a low density and insufficient bearing capacity. The minimum overhang of the brackets and the dimensions of the guides are determined by the results of a static calculation, the thickness of the insulation and possible deviations of the outer walls from the vertical. To safely compensate for thermal deformations of the system, the length of individual guides it is not recommended to carry out more than 3.6 m of aluminum profiles. The size of the gap between two adjacent guides vertically is determined by calculation based on the coefficient of linear thermal expansion of the guide material. The air gap between the thermal insulation layer and the cladding, as well as the gaps between the individual cladding elements, ensure moisture exchange processes in the external enclosing structures of the building The design size of the gap between the heat-insulating layer and the cladding should not be less than 40..60 mm and not more than 200 mm. insulation, type of disc dowels and a diagram of their installation. It is allowed to install a single-layer moisture-proof membrane from the outer surface of the insulation. At the same time, in most cases, for the purpose of fire-prevention measures, it is necessary to provide for fire-prevention cut-offs, covering the air gap with a certain height step. The use of windproof membranes in combination with mineral wool boards with a "cached" outer surface is prohibited.
It is not allowed to attach signs, advertising installations, lighting fixtures, etc. to the frame and LFS cladding structures. In the case of using a hinged facade system on buildings with a height of more than 75 m, it is necessary to develop technical specifications for each specific building, which should take into account the requirements of the technical certificates of the NSF for buildings of lower height.
Requirements for materials
The ventilated facade is a responsible engineering structure that forms the outer protective shell of the building. The durability and normal functioning of the NSF is ensured by the use of materials and components that correspond to the list of materials of the technical certificate for the system and have documents confirming the quality of the materials and indicating their manufacturers.
The material for the TATPROF ventilation facades substructure is an aluminum profile made of 6060 T66 (T6) alloy, manufactured in accordance with the requirements of GOST 22233-2001. Based on the state of delivery, in accordance with SNiP 2.03.06-85 "Aluminum structures", the design resistance of the material to tension, compression, bending is determined for the subsequent performance of strength calculations.
The load-bearing elements of the ventilation facade (brackets, guides, anchors, fasteners) and the heat-insulating layer must have a standard service life of at least 30 years for buildings of the II level of responsibility and at least 50 years for buildings of the I level of responsibility. For the aluminum profiles of the TATPROF building system, which are part of the nomenclature of ventilation facades, tests were carried out and a conclusion was obtained that their service life without additional protection in a non-aggressive and slightly aggressive atmosphere is 50 conditional years; in a moderately aggressive atmosphere - 40 conditional years; in the seaside atmosphere - 30 conditional years. The use of additional protection in the form of electrochemical anodizing and painting with polymer powder paints helps to increase the service life.
Facing materials must have physical and mechanical characteristics that ensure the possibility of their use in LFS, including sufficient bending strength and frost resistance (150 cycles).
When installing thermal insulation in one layer, non-combustible mineral wool boards with a density of at least 80 kg / m3 should be used. When installing a two-layer thermal insulation, the inner layer can be made of mineral wool boards of the G1 grade (low-combustible), and the outer layer of mineral wool boards of the NG grade (non-combustible). In this case, the inner layer of the slabs can have a density of 30 - 80 kg / m3. The standard service life of thermal insulation in this case is determined by the service life of the inner layer. The standard service life of the disc dowels must be at least the standard service life of the heat-insulating layer. The characteristics of the wind-waterproof membrane used must comply with the requirements of the Customs Union for these products.
Carrying out calculations for bearing capacity and heat engineering
When calculating the substructure of the ventilation facade for the bearing capacity, depending on the type of fastening and the placement of the brackets, one of three schemes is chosen:
Type I - one-, multi-span continuous beam with consoles, rigidly fixed to the upper support;
Type II - multi-span continuous beam, fixed in a universal bracket (rigid and movable fastening in one unit);
Type III - multi-span continuous beam rigidly fixed to the second support.
When calculating the load-bearing elements of the frame, the most unfavorable loading should be selected from 2 options:
Option 1 - the sum of the total wind load, dead weight of the substructure and cladding;
Option 2: the sum of the 25% calculated wind load, the own weight of the substructure and cladding, as well as the ice component.
In this case, the calculated wind load consists of two components - the main and the pulsation - and is determined by the formula for finding the peak wind load in accordance with SP 20.13330.2011 “Loads and Impacts”. The snow load should be taken into account when calculating the protruding or falling sections of the cladding screen.
Based on the minimum required inertial characteristics obtained from the results of calculations, the profile of the guide is selected. The TATPROF ventilated facades have a wide range of guides with a height of 60 to 180 mm and a moment of inertia from 6.65 to 335.38 cm4, which allows placing brackets on the facade of a building with the maximum possible height step.
The heat engineering calculation of a wall with a hinged facade system is performed as for a homogeneous multi-layer structure according to the formulas of SP 23-101-2004 "Designing thermal protection of buildings". In this case, the heat transfer coefficients of the outer and inner surfaces of the enclosing structure and the total thermal resistance of the wall itself and the thermal insulation layer of the ventilation facade are taken into account.
The maximum possible thickness of insulation in TATPROF ventilated facades is 320mm. Depending on the thickness of the insulation and taking into account the minimum air gap of the curtain wall system, a bracket of the required overhang is selected. The building system "TATPROF" has brackets with an outreach from 60 to 220 mm, as well as extension cords. At the same time, there is also the possibility of performing ventilation facades without insulation, if, according to the results of the thermal engineering calculation, the heat transfer resistance of the bearing wall is sufficient.
Requirements for the supporting base for the installation of the ventilation facade
Acceptance of external walls intended for the installation of LFS is carried out in accordance with the requirements of SNiP 3.03.01-87 "Bearing and Fencing Structures" and is drawn up by the corresponding "Act". The permissible values of deviations from the vertical and horizontal between the monolithic sections, from the design lengths of the elements, the magnitude of local irregularities should not exceed those indicated in table. one.
The verticality of the edges, corners of brickwork and blocks, as well as the places where the masonry adjoins the concrete frame, the horizontalness of its rows must be checked in the process of laying the masonry every 0.5 - 0.6 m with immediate elimination of deviations within the tier. The permissible deviations in the size and position of stone structures and wall filling should not exceed the values given in table. 2.
General provisions for installation
The schematic diagram of the installation of a ventilated facade is as follows:
- supporting elements (brackets) are attached to the wall surface using anchor bolts or dowels;
- install heat-insulating plates, which are fixed with disc dowels;
- heat-insulating plates are covered with a vapor-permeable wind-waterproof membrane;
- guides are mounted on the brackets;
- cladding elements are hung on the guides with the help of fasteners.
Installation of LFS is carried out in accordance with the project after its binding to the building envelope on the basis of the executive scheme (based on the results of geodetic surveys) and geometric measurements.
Installation of thermal insulation boards begins from the bottom row, which is installed on the starting perforated profile or base and is carried out from the bottom up.
If the slabs are installed in 2 layers, it is necessary to ensure that the joints of the 1st layer are covered with the slabs of the 2nd. Plates should be installed close to each other with filling (if necessary) the gaps between them with the same material. The permissible size of the unfilled joint is 2 mm. When installing thermal insulation boards, they must be trimmed with a special tool. It is prohibited to break the insulation plates.
Heat-insulating plates are mounted in accordance with the scheme specified in the technological map. The project must indicate the minimum permissible number of fasteners. With two-layer thermal insulation, it is necessary to ensure that the inner layer is tightly pressed against the wall surface. The number of disc dowels installed in the first layer on a plate with dimensions 1000 × 600 mm must be at least 4 pcs. Additional heat-insulating elements must be securely fixed to the wall surface with at least two dowels.
The sheets of the windproof membrane are installed with an overlap of 100 mm.
The windproof membrane is attached close to the plates with disc dowels at the rate of 4 pcs. per 1 m2.
In accordance with the project, vertical or horizontal guides are attached to the brackets. The position of each profile in the vertical plane is checked with a theodolite or plumb line. For the convenience of mounting T-, L- and Y-shaped guides in the ventilated facades of TATPROF, L-shaped brackets with “clothespins” are provided - elements for fixing the guide until the moment of final fixing to the brackets. When using U-shaped brackets, for the convenience of mounting box-section guides, there are skids that allow you to perform both a movable and a rigid connection.
Installation of cladding elements starts from the bottom row and is carried out from the bottom up. If the project provides for non-standard cladding elements, or special architectural conditions, the joint work of the profile manufacturer, the manufacturer of the facade structure and the project GUIs begins to design the necessary assemblies and fastening cards. So, based on the roof series TPSK-60500, TATPROF has developed a special design solution for pressure and rubber to implement the structural design of the roof of the Great Ice Arena SOCHI-2014. The series is designed without clamping strips, so that the joints are in the same plane with the glass, which made it possible to achieve the most smooth and uniform surface of the dome, while observing all regulatory and technical parameters.
Compliance with all these conditions allows TATPROF to be the leader in facade profile systems in Russia. According to Sergei Rachkov, Chairman of the Board of Directors of CJSC TATPROF: "Unswerving adherence to a precisely planned strategy, business principles, company mission - all this bears fruit in any market fluctuations. The trust of our clients and partners combined with a clear understanding of laws and market trends allows us to look to the future with confidence. Highly efficient production, modern management, unconditional fulfillment of contractual obligations - these are the components of our business success!"
Welcome to cooperation!
