In the past few years, thermal cladding has become increasingly widespread in Europe due to the growing statutory and technical requirements to ensure heat comfort in both new builds and renovations. The insulation of any building envelope is the first step to ensuring the reduction in energy flows and consumption in any building, and translates into improved comfort for users and financial savings due to lower energy consumption to heat and cool the inside.
The thermal cladding system using Ultra slabs changes the outer layer of conventional cladding systems which have mineral finishes, but adds greater value with the finishing layer in thin porcelain stoneware slabs.
The thermal cladding system involves the laying of a 6 mm thick porcelain stoneware slab on top of a heat insulating layer (the thickness of which is decided according to design calculations).
The proposed system requires a mechanically resistant support, designed using a covering and laying system on EPS or XPS (respectively, expanded polystyrene or extruded polystyrene) insulating panels with high mechanical resistance (to traction and compression) and low elastic modulus, able to support the weight and stress generated by the coverings and by thermal expansion.
The insulating layer must have a rough surface in order to allow the covering to grip, with square profiles and no ledges, of a thickness established in the design calculations. For covering slabs, pale colours with a reflective index of greater than 20% should be chosen.
Having said this, it should be underlined that the achievement of expected results in terms of heat insulation and durability of the outer covers is closely related to the careful and correct design of the construction details of the system, in all points which could create a thermal bridge, as well as the correct installation of the system.
CLADDING SYSTEM LAYING SEQUENCE
THE FOLLOWING RECOMMENDATIONS HELP TO ENSURE THE CORRECT INSTALLATION OF THE CLADDING SYSTEM:
1. The system should be laid using the double glue spreading method, spreading the glue on both the underlying surface and the back of the slab, to prevent voids between the covering and the support, where rainwater could filter in and (in the event of frost) create stress which could cause the slab to become detached. Moreover, this method ensures that the stress caused by the differential movements between the slabs and the support surface, due for example to variations in temperature, is spread more evenly, thus preventing efflorescence on the façade.
2. The slabs must be laid with wide gaps to suit the slab size and the local climatic conditions.
3. Structural joints must be fitted to suit both slab size and position. Expansion joints must also be inserted along string courses, corners and ridges (and in any case every 9-12 m2)
4. The covering must be protected against water infiltration and potential damage from freezing-melting by fitting suitable seals or metal
flashing on the top and bottom of the whole covering, as well as around doors and windows.
THERMAL CLADDING SYSTEM USE
The Cladding System is used in all new builds and renovations where the building envelope has to be insulated, and to meet statutory
requirements concerning the transmittance of vertical components and energy needs linked to the building.
It should be underlined that in the case of new builds or large-scale renovations, the above-indicated performance requirements are
obligatory and that incentives in the form of tax deductions may be available for energy efficiency measures (including thermal cladding systems).
The diagram below describes the size ranges and some key indications for gluing Ultra slabs on outer walls with thermal cladding.
The size range is purely indicative, as external coverings can be produced using Ultra slabs of all sizes (up to 150x150 cm).
NOTES: The size range is purely indicative, as external coverings can be produced using slabs of all sizes (up to 150x150 cm).
The key refers to the height above ground of the building.
EPS:Sintered expanded polystyrene