in its natural state; unprocessed.

fissured longitudinally; natural appearance.

elongated notches or incisions that provides the stone a rustic appearance.

having surface indentations produced or appearing to have been produced by a special tool

high temperature treatment that granitic rocks’ surfaces are subjected in order to obtain a rough, cratered and vitreous surface. The final appearance of the stone is rustic.

roughen or clean (a surface) with a jet of sand driven by compressed air or steam.

polished but not shiny; rustic surface.

to cut the stone’s surface with a diamond teeth disc or steel strapping; the resulting surface is smooth but rough.

similar to the polishing process, but the surface is not shiny.

abrasive grain are applied with polishing machines, obtaining a smooth and shiny surface of the stone.


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Square or rectangular tiles. It is possible to use tiles of the same size or to alternate half tiles from row to another. Tiles could also be placed in a diagonal shape or any other shape, but the final appearance must be regular.

Straight Flight | Two Flights | Three Flights | Imperial | Four Flights | Curved Flight.

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German Formula: 2 rise heigh (h) + 1 tread depth (T) = 63 cm
Spanish Formula: 2 rise heigh (h) + 1 tread depth (T) = 64 cm
Comfortable rule: 1 tread depth - 1 rise heigh = 12 cm
Security rule: 1 tread depth + 1 rise heigh = 46 cm
Ideal step: h=17 cm ; T = 29 cm
THE "BLONDEL THEOREM" 2 rise heigh (h) + 1 tread depth (T) = 60 t 64 cm (module)or 2r + h = module (m)where: h: The heigh of the step; it is between 15 and 21 cm. For most cases, 17 cm is the ideal. T: The tread, the part of the stair that is stepped on. m: The module, is equal to the length of an average walking step.

The Harrow method --> L stairs. This method proportionally reduces the read on the well side but keeps it constant on the walk line. To be efficient, this method requires that at least seven steps are wedge shaped: The one in the angle and 3 on each side.

This L-shaped stair has 15 steps. The ninth being the one in angle. Steps are web shaped from the 3rd to the 14th. -> First, draw regular treads on the walk line. All the steps from A to C will be wedge shaped. - -> The BD line cuts the angle in the middle. E is the intersection point of BD and the walk line A'C'.

-> On a different drawing (figure a) trace an horizontal line on which the length of AB is reported. On the vertical line, the treads of the steps 3 to 8 are reported and the length of the portion of the tread from the ninth step which is cut by the line BD (Point E). -> Each tread on the line AE is then linked to point B. - -> Then trace an arc with A as a center, the radius is AB. This arc cuts the BE line on the point B'. -> The new length of the treads are found on the line AB'. This distances are to be reported on the AB line of the first drawing.

The mortars and the glues

Mix calculations
For 1 m3
of dry sand
  • From 800 kg to 1100 kg of cement.
  • From 400 kg to 1000 kg of hydrated lime.

Cementitious adhesive are used according to recommendations of the manufacturer.

Sand grain sizes


  • 1,5 – 2 mm
  • 2 – 10 mm
  • > 10 mm


  • 1,5 – 2 mm
  • 2 – 10 mm
  • > 10 mm


o To lay white or light coloured stones, use white lime or cement in the mortar mix.
o It is better to try the mortar mix on a sample of stone to see if stains appear before applying it to a great surface.
o It is better to use a low alkaline blinder.