Traditional mortar screed

Fixing tiles on a mortar screed is the most traditional method.   It is used for both exterior and interior floors.   It allows the incorporation of plumbing and electricity piping.

It is composed of stable sand class 0,08/5 mm with minimum 100 kg of hydraulic binder per m3 of sand, or a weak mortar of 150kg. Typical composition of a lime/cement mortar: 175kg of white cement, 175 kg of hydraulic lime to 1 m3 of fine clean sand

The thickness of the mortar varies between 20 and 50mm according to the type and dimensions of the tiles to be fixed.

This can be applied on different supports :

Howewer it is prohibited on en recent concerte base

Do not soak the tiles before fixing as one should avoid any excess of water which is often the cause of the screed settling, as well as the reduction of its impermeability.  One must remember that while the mortar screed is drying water will evaporate through the stone.   Any particles in suspension or dissolved salts will penetrate to the surface where they will accumulate in the form of efflorescence.