The substrate must be flat, smooth, clean, (free from loose material, dust, greases, oils, waxes, paints, detaching agents and any other items which may reduce adhesion), and free from cracks. Moreover the substrate must be compact, dry, mechanically strong, cured and dimensionally stability. The tiles must be laid on cured screeds which have already completed most of their shrinkage due to water loss, ensuring that there will be no cracking after the floor covering has been installed, with the consequent risk of broken or loose tiles.
The tiles must be installed using high-performance, elastic cement adhesive. Any uneven points will require excessive grinding, which may spoil the whole floor.
In case of polishing after laying, regardless of the type of material and thickness, it is essential to use the double-spread technique.
Existing expansion joints and laying joints must comply with the reference standards before grunting the joints. The laying joints (grouts) have to be clean, free from dust and have to be sufficiently large to let the grout penetrate deeply and last in time.
Joints may be sealed with grunting cements or suitable fillers with color as similar as possible to the color of the terrazzo tile. It is essential to remove sealant residues from the tiles while still fresh.