Primarily in the case of public buildings, but often also in residential buildings, it is possible to create façade cladding from high-quality materials in addition to or instead of a simple render.
1. Bonded wall claddings
The claddings can be installed by glueing them directly onto the wall. Common coverings include:
The cladding is installed in a similar way to ceramic floor coverings:
First, the factory-made dry mix is diluted with water and stirred. Then the elements are affixed to a thin adhesive bed applied to the wall with a notched trowel. The cladding is installed from the bottom up, using tile spacers to maintain an even distance between the tiles. External wall corner profiles are used at the outside edges corners. Flexible adhesive must be used outdoors, and the appropriate expansion joint requirements must consider how to eliminate stresses caused by thermal movement. The coverings can also be installed on thermally-insulated wall structures; in this case, we use the same method as rendered thermally-insulated walls to install the thermal insulation.
2. Masonry wall claddings
Brick cladding is a masonry structure independent of the wall; that is, the cladding must be built in the same way as if we were erecting a separate brick wall. As per the rules of bricklaying, horizontal and vertical mortar joints should be created.
However, the area behind the cladding can be constructed as a mixed structure, typically with a 4-centimetre-thick cement mortar backing and the brick wall built directly in front of the load-bearing structure.
It is more common - especially in multi-storey buildings - for the supporting structure and the cladding to be completely separate from each other. In this case, there are three options:
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Simple air gap cladding
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Thermally insulated cladding without an air gap
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Multi-layer thermally insulated cladding with an air gap – the latter is the most common solution.
To start, we build a one-brick wide wall for the brick cladding on a common foundation with the load-bearing wall. Alternatively, we can begin from steel support brackets which we attach to the base of the walls with dowels or anchor bolts. This is only feasible if the lower wall consists of reinforced concrete, and this section is appropriately dimensioned as a ring beam to support this load.
The connection between the wall structure and the brick cladding is achieved by steel wall ties, whose hooked ends are placed in the horizontal joints of the cladding. These must be placed every third row, 50-70 cm apart. The hanger bracket attached to the ring beam supports the brick cladding from below and supports the bricks above wall openings, which are also held in place by the metal rods.
3. Mounted wall claddings
a) Wooden claddings
Mounted wooden cladding can be created in various ways. One less common option is shingle cladding, made from spruce or Scots pine and nailed onto a wooden sheathing or batten frame to form a double lap cladding.
A more common solution is horizontal panelling made of tongue-and-groove boards, which are attached to a batten frame with hidden nails. Board cladding is usually applied vertically in two rows that partially overlap and is also fixed to a batten frame.
A modern solution is an impregnated, 15-20 mm thick laminated veneer lumber (lvl) cladding, with a metal support frame constructed for the large panels. When installing the cladding, care must be taken to ensure that the area behind it is ventilated and that there is space for the required thermal insulation (rock wool is advised). It is recommended to protect the thermal insulation layer with a vapour control layer on the outside.
b) Metal cladding
Similar to flat-sheet covering of the roofing, metal cladding can be installed on façade walls in conjunction with the roofing system. Aluminium, zinc, or stainless steel sheets are commonly used. To create traditional flat metal cladding, continuous sheathing is required, onto which double-lock standing seam or single-lock (angle) standing seam metal cladding is formed from pre-profiled sheets. Metal cladding can be made from corrugated, trapezoidal, or other profiled sheets, which are typically available in large panels for order or purchase. The sheets can be fastened to a wooden or metal support frame using exposed screws, rivets, or concealed fasteners. Finally, metal cladding can be made from panels or cassettes, with interlocking flanges and made of solid or even perforated sheets. For metal cladding, the metal support frame must also be designed in a way that ensures sufficient space for thermal insulation and an air gap.
3. Ceramic tile cladding
There are two known types of mounted ceramic panels. Solid panels are around 1 cm thick, while hollow-core panels are around 3 cm thick. The difference is also reflected in the method of fastening:
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Solid panels are fastened using steel hooks protruding from vertical support members which grip the four corners of the square or rectangular panels.
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Hollow panels have vertical support members which carry horizontal mounting rails, onto which we clip the fastening profiles. The flanged design of the panels allows the fastenings to remain hidden and the horizontal joints to be invisible. Joint closure profiles are used for vertical joints.
Thermal insulation is fitted between the support members in the case of ceramic cladding.
4. Fibre cement slate cladding
Small-element fibre-cement slate cladding is only 4 millimetres thick, while large-format, meter-long fibre-cement slate slabs are 8-12 millimetres thick. The panels or slabs can be fixed to vertical timber battens or metal support rails, between which a few centimetres of air gap provide thermal insulation for the wall. The fixing method can be exposed (riveted or screwed) or concealed (bonded or hooked).
5. Stone panel cladding
Mounted stone cladding is typically made of standard, sawn stone panels, 3-6 centimetres thick, with open-joint installation. The stone type can vary: limestone, granite, sandstone, or even marble panels. The surface finish of the panels can also vary: For example, polished, honed, or split-faced etc.
There are two basic types of fixing methods:
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Point-load bracket fastening can be achieved with tongue-and-groove elements at the top and bottom.
The head of the bracket is located in the horizontal joints, from where the pins extend into the pre-drilled holes in the stone panels.
In certain cases, only side fastening is possible (e.g., above openings).
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In the metal frame version, pin fasteners are applied to horizontal mounting rails supported by vertical metal support profiles.
Thermal insulation requires a minimum air gap of 3 centimetres to be maintained between the thermal insulation batts and the back of the cladding.
6. Cast stone cladding
Cast stone tiles are often used as plinth claddings. The plinth cast stone panels typically start from the same strip footing as the clad wall; behind them are concealed extruded polystyrene thermal insulation, as well as vapour or waterproofing membranes. The panels are typically fixed using adhesive bonding or mechanical hangers.
