Securing the thermal insulation boards


With the laying of the thermal insulating layer can be started only when:     

- all wet processes (applying coatings, plastering, etc.) inside the building are completed
- the door frames, window frames and window sills are installed (in order to avoid wetting the Thermal Insulation System)     
- the surfaces of all surrounding building elements are covered and properly protected (window, frames, window sills, etc.)     
- the base is checked and prepared     
- there are solutions and concrete plans for the implementation of all construction details

The application of the thermal insulation system should be performed so that it can bear all the loads in time without being destroyed or damaged.

The loadings, to which one Thermal Insulation System is exposed, are the following:     

- the proper weight of the system     
- loads of suction caused by the wind      
- thermal loads caused by the daily and annual fluctuations in the air temperature and the sunshine     
- hydro-loads cause by the contraction of the material, fluctuations in the air humidity and the influence of the heavy rains     
- loads caused by deformation of the walls

The proper weight of the completed system may vary, depending on its type and method of installation, from10 kg/m2 to 50 kg/m2. In a properly constructed system (through bonding and doweling) these loads are borne primarily by the adhesion strength of the adhesive to the base and the shearing strength of the thermal insulation material.

The strongest load, to which a thermal insulation system is subjected, is its suction from the wind that is formed in the parallel and opposite to the direction of the wind sections. These loads are borne mainly by the dowels in the system.

The thermal and hydro loads are commonly grouped under the term hydro-thermal loads (shrinkage of the mortars at drying, temperature and moisture loads). As a result, inside them are formed tensions and displacements of mortars and screeds from the base in the area of the edges of the facade, which leads to the appearance of cracks in it, or even to the separation of the entire system from the base.

The Thermal Insulation System loads, caused by the deformation of the walls must be taken by a constructive way through an installation of deformation joints or by selecting a Thermal Insulation System, installed by splints instead by bonding and doweling.

 

1 - Air pressure        2 - Air suction

When bonding the thermal insulation boards, the adhesive can be applied both on the board and on the base. There are three methods of bonding the boards: bonding balls, bonding over the entire surface and machine bonding.

When placing the balls, on the circumference of the board a strip of adhesive is applied, which fixes its edges and corners and thus it reduces the deformations, occurring at hydro-thermal loads. Thereby the movements of the air behind the boards are prevented. From 3 to 6 balls are applied in the middle of the board, which prevent its bulging forwards (protrusion). By this method of bonding the total surface, covered with adhesive, should be ≥ 40%, and at systems with ceramic coverings ≥ 60%. At one of the edges of the board is left a gap, so that when pressing to the base, the air behind it to be able to come out (otherwise an airbag is formed and the board cannot be adjusted and leveled well).

 

When bonding over the entire surface, the adhesive is applied on comb over the entire surface of the board with the help of toothed spreader with teeth width 20 mm. When applying, the teeth of the spreader should reach the board, so that a sufficiently enough channels will be formed, which will provide space for spreading the adhesive after pressing the board to the base. When bonding by this method is allowed applying of adhesive on the base too.

 

When machine bonding the adhesive can be applied both on the board and on the base. The total covered with adhesive surface should be ≥ 60%.

 

The arrangement of the plates is carried upwards. The boards are placed horizontally along the facade, close to each other, leaving no space between them. The forming of cross joints between the boards is not allowed, as for this purpose they diverge horizontally with half board. It is not allowed for the joints between the boards to continue the lines of the openings in the facade (windows, doors, etc.)

The surface of the places insulation layer should be smooth, without steps and unevenness.Irregularities between the levels of the boards should be removed through grinding.

In the gaps between the boards and their front sides should not get adhesive or it should be cleaned if any. Wrong places and large joints should be sealed with the same insulating material. Joints with width up to 5 mm can be sealed with polyurethane foam.

On the edges of the building the thermal insulation boards are tooth-crossed, thus ensuring the sustainability of the grip in these areas.

 

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