The quality of a work performed using natural stone depends on good design, careful processing of materials and their correct installation.
In the design phase it will be necessary to provide an adequately dimensioned load-bearing layer designed to ensure solidity and integrity, as well as a compact foundation that supports a good and long-lasting adhesion of mortar or natural stone glue. The integrity of the flooring and the appearance of fractures or cracks on the stone surface will depend on the correct creation of these elements, as well as on the preparation of the necessary joints.
The “State-of-the-Art” installation of stone materials achieves an appreciable overall aesthetic harmony without unevenness, enhancing the nature of material and showing a uniform and well-identified installation texture; it achieves a sufficient surfaces flatness allowing regular drainage of the surface waters in external pavings avoiding any possible stagnation; it allows to preserve the work intact and undamaged over time reducing ordinary maintenance to the minimum necessary.
The experience, the hand and the eye of a good installer influence the result of a work, sometimes even in a decisive manner. The installer must have good skills, experience and appropriate technical equipment and he must also follow the instructions given by the manufacturer and the construction manager. It is therefore important for the operator to be fully aware of the overall executive drawings, of the dimensions, alignments, installation tolerances, of the cutting and processing instructions, making sure that they are in compliance with the actual operating conditions found on the site, taking care to make remarks or propose specific solutions if necessary.
At the construction site all the materials needed for installation must be stored, handled and treated so that they are not damaged or altered in any way and stored in suitable places, protected from possible impacts or contact with other construction site operations.
The weather conditions must be favourable to the required processing, in particular the air temperature must not be lower than the minimum prescribed by the glue used and not even lower than the freezing level if water is used in the mix.
The surface must be in proper conditions and all the materials used in the installation cycle must not cause stains, oxidation, efflorescence. In particular, the water must be clean, free of iron oxides, salts and any other impurities or substances capable of causing irregularities in the setting process or efflorescence; it must be used in the right doses, in order to avoid floating or the chalking of the beddings. Aggregates and binders must be free of earthy and clayey substances, salts and oxides and organic substances.
The sealing operations must be started at the end of the drying of the bedding layer and be completed, even by sectors but without visible restarts, respecting the setting times of the materials used. As the sealing is a finish particularly important for the success of the work, it must be carried out on clean surfaces, putting into practice all the necessary precautions. In the case of external paving, the sealing must fill all the empty spaces between the elements so as to prevent possible infiltration of water which, transformed into ice by winter harshness, could cause the detachment of the elements and the instability of the entire paving.
Experience shows that the time between the end of the installation operations and the end of the construction site is very delicate due to operations often performed on the finished surface without the necessary precautions to avoid breakage, scratches, stains and so on. It is therefore always advisable that the installation of natural stone (paving and stairs, especially outdoors), is performed when all or most of the other finishing construction works, including plasters, have been completed.
In the case of interventions on stone surface for the removal of marks or stains or the protective treatment with impregnating agents, it is absolutely necessary that each product used is suitable for the material and does not cause damage to the stone finish or to the sealing, the operations must be carried out by skilled personnel with the correct procedures and timing.