Of fundamental importance are correct analysis and consequent profound knowledge of the mechanical specifications and state of conservation of the substrate, with particular attention paid to existing ones.
Type of substrate
Technically the wall substrate is not a constituent element of TermoK8®; however, as it has to provide adequate support for the system, which is in turn subjected to stresses of various kinds (its own weight and that of any loads, wind, thermal expansion and contraction…) it requires special attention and specific treatments: it is therefore necessary to consider it as one of the components of the system.
Characteristics of the surfaces
- The surfaces must be on the same plane and must not be too rough or uneven (with a four-metre bar the differences must not be more than 7-10 mm). Otherwise, the substrate has to be rectified.
- The surfaces must be dry and free from permanent humidity, including rising damp.
- The surfaces must be coherent and offer good mechanical resistance and adhesive capacity.
- The surfaces must not be too absorbent: the adhesive applied could later dry out and lose adhesion and coherence.
- The surfaces must be free of foreign bodies (nails, dowels, tie rods…), cleaned of dust and residues of any kind.
Irrespective of the condition and characteristics of the surfaces, it is always possible to guarantee perfect adhesion of the coating by adopting specific restoration solutions and/or choosing the system best suited among the many solutions that TermoK8® offers, depending also on the type of substrate.
In both cases, careful planning will ensure that correct mechanical fixing of the system is identified.
Preparation of the surfaces
In the case of surfaces covered with mortar made with hydraulic binders, check carefully the condition, verifying the adherence and cohesion; any parts which are deteriorated and detaching must be removed and then made flat again.
The substrate must first be cleaned perfectly using the most appropriate methods for the purpose (mechanical brushing, washing with hot water and detergents, pressure washing, sandblasting).
In the case of painted render, any paint peeling off must be removed and the surfaces treated with a special primer, taking care not to ''vitrify'' the treated surface.
In the case of new constructions, sufficient curing time must be allowed for the surfaces: this is variable from 30 to 45 days from the cast; then, if necessary, the support must be washed. In the case of intervention on degraded surfaces it is necessary to repair them with suitable treatments and to clean them carefully.
In the case of walls tiled with stoneware, clinker or glass paste elements, it is necessary to examine the entire surface, remove any loose parts, recreate a flat surface with cement mortar and clean the substrates.
In the case of glazed tiles a treatment to ''roughen'' the surfaces is recommended.