DOUBLE FIRED TECHNICAL CHARACTERISTICS

UNI EN 14411 (ISO 13006) - BIII (Appendix L) GL

Double fired tiles are made with clays obtained from our own quarries and with fireclays (chamotte). These raw materials are submitted to dry grinding and suitably mixed and wet and then pressed with hydraulic presses.

Quick-cycle support firing is obtained via roller kilns reaching temperatures of approximately 1100 °C. After biscuit glazing, the vitrified product is sintered in a single-layer roller kiln at approximately 1030 °C. The resulting wall tiles have an average bending strength that is higher than 15/ mm2 in accordance with the UNI EN ISO 10545-4 standard and a water absorption level that is higher than 10 %; they belong to the BIII (GL) group according to the UNI EN 14411 standard. This class of products shows virtually no shrinkage during firing; therefore such dimensional consistency results in extremely easy laying.

ADVICE ON LAYING

Double fired tiles can be laid using either tile adhesives or cement mortar. Under no circumstances should the tiles be wet before laying when using acrylic or vinyl resin based adhesives or two-component organic solvent based adhesives. When laying large sized tiles it is best to adopt the two layer spreading method and, when the laying surface is very large, to provide for suitable expansion joints which must not be spaced more than 4-5 linear meters apart from one another.

To follow is a list of laying conditions to be avoided in that they could bring about problems:

• When laying on wet concrete or plaster, leave to dry for at least one week for each centimetre of thickness.
• When laying on brick, never lay on tile adhesive measuring more than 4-5 mm in thickness.
• For laying on flexible supports (for example plasterboard, panels, polymer panels, ect.) which may bring about a movement of the tiles we advise laying on tile adhesive measuring no more than 2-3 mm in thickness and to use class C2 or D1 glues.
• For laying on waterproof brick, which prevent the release of damp, we advised laying on the tile adhesive measuring no more than 3 mm in thickness and to use class C2 or D1 glues.
• Avoid laying without expansion joints or joints, where the stress due to expansion is released directly onto the tile.