• The broken natural stones are characterized by different shades of colours, varying thickness and by the structure of their surface (more or less smooth). In order to obtain the best natural effect and to enhance these characteristics, we suggest you, when lying, to take out of the packaging all the tiles and/or irregular pieces and to distribute them by mixing the different shades of stones;
  
  
• external lying can be only made when temperatures are > 0°;
  
  
• in order to protect the flooring from stains of oil or grease, you should treat it with the products of the Company FILA Industria Chimica S.p.A. (www.filasolutions.com), to be spread after the final laying and when the floor is clean and dry, i.e. 20-30 days after the laying. Water and oil-repellent products also make the cleaning easier, as they increase the water resistance of the stone. The application of these products must be made only  according to the suggestions on the label;
  
  
• however, the layer is always responsible for the laying.

Traditional laying with mortar

• suggested mixture of the mortar, to allow that it sticks well, notwithstanding low and high temperatures and as much waterproof as possible, is made up of:
  300 Kg. of  white cement  -  1 m³ of fine sand;
  

• the advantage of white cement is that it reduces considerably the probabilities of superficial efflorescence after the laying;
  
  
• mortar must be spread on a bed of cement, previously cleaned and wetted (no stagnation of water), in order to avoid adherence problems;
  
  
• the bed of cement must be made at a height which allows to contain both the thickness of the mortar, between 2 cm. and 5 cm., both that of the stone to be laid;
  
  
• the mortar should not be spread to the total area to be covered, but only to that required for the laying of two or three pieces. Before laying, it is necessary to wet with water the laying face, then to apply a layer of liquid cement. These two processes, in addition to improving the adhesion of the stone, allow to reduce the absorption of any substances which can cause stains, present in the mortar;

• before starting the laying, it is recommended to wait until the mortar has slightly hardened;
  
  
• sometimes opus pieces must be cut before being laid, so that they can fit perfectly. This can be easily obtained with the use of a hammer;

• the layer must always get the walking surface by using the smoother face of the stone;
  
  
• to avoid gaps and to allow that the stone rests entirely on the mortar, it is recommended to beat it gently with a rubber hammer;

• during the laying, it is very important keeping always clean the stone surface. To this purpose, we suggest using a sponge wetted with clean water;

• the joints between the pieces of opus must be between 15 and 25 mm. They must be sealed, after coating the entire surface. To this purpose, it is necessary to use a mixture made up of 1/3 fine sand, 1/3 of white cement and 1/3 of clean water. It is necessary to fill the joints with this mixture until they are full. As soon as the mixture begins to dry, it is recommended to remove the excess with a trowel first and then to wash using a sponge wetted with clean water;