When preparing for the formation of a PAVING or WALL COVERED by natural stone, it is essential to have a perfect knowledge of the support, i.e. of that structure, horizontal or vertical that will be completed with the application of natural stone.
The support can be made up only of load-bearing elements but much more commonly it also includes other layers having different functions.
The most common load-bearing layers of external horizontal supports are: ballast; cast-in-place reinforced concrete.
Stone covering layer
it is the surface finish consisting in the stone elements. This layer must be installed with the utmost care, as this work consists in what the user will enjoy and see.
Installation bedding layer
placed in a position immediately below the paving elements, it has the function of binding the stone to the underlying layer, for example for interiors in a cement screed (which often acts as a regularization + levelling + system integration layer) or for exteriors in a reinforced concrete casting (acting as a load-bearing layer). The bedding can be composed of cement mortar and have a thickness of several centimetres, or by adhesives of various nature for a thickness of a few millimetres and never greater than one centimetre;
Foundation layer
The installation foundation is the surface of the layer immediately below the mortar or adhesive bedding layer that must guarantee a solid adhesion. For example, it may consist of the loadbearing layer slab surface or of the levelling layer surface, or, in the case of exteriors, of the stabilized ballast surface or of the reinforced concrete casting.
A good foundation is the essential prerequisite for any paving: it guarantees the adhesion of the mortar or adhesive bedding, distributes the concentrated loads to the underlying layers avoiding local yielding and alterations, reduces the risk of fractures or cracks and preserves the integrity of the paving over time.
THE SUPPORT
The support can be made up only of load-bearing elements but much more commonly it also includes other layers having different functions.
The loadbearing layer
In traditional constructions the main types of load-bearing layers that make up internal horizontal supports are: mixed brick-cement slab; cast-in-place reinforced concrete slab; slab with prefabricated concrete panels also light type ("predalles"); floor with prestressed prefabricated elements and brick; steel slab; mixed steel and brick slab; wooden slab.The most common load-bearing layers of external horizontal supports are: ballast; cast-in-place reinforced concrete.
The other layers
With reference to the standard UNI 7998:1979 “Building. Floorings. Terminology.” and UNI 8381:1982 Building. Flooring support layers. Instructions for design and execution.” the presence of the supporting layers interposed between the load-bearing layer and the walking surface must be taken into consideration, such as: draining layer, regularization layer, levelling layer, slope layer, separation layer, stiffening layer, system integration layer, waterproofing layer, thermal insulation layer, insulation layer, as well as specifically for stone pavings:Stone covering layer
it is the surface finish consisting in the stone elements. This layer must be installed with the utmost care, as this work consists in what the user will enjoy and see.
Installation bedding layer
placed in a position immediately below the paving elements, it has the function of binding the stone to the underlying layer, for example for interiors in a cement screed (which often acts as a regularization + levelling + system integration layer) or for exteriors in a reinforced concrete casting (acting as a load-bearing layer). The bedding can be composed of cement mortar and have a thickness of several centimetres, or by adhesives of various nature for a thickness of a few millimetres and never greater than one centimetre;
Foundation layer
The installation foundation is the surface of the layer immediately below the mortar or adhesive bedding layer that must guarantee a solid adhesion. For example, it may consist of the loadbearing layer slab surface or of the levelling layer surface, or, in the case of exteriors, of the stabilized ballast surface or of the reinforced concrete casting.
A good foundation is the essential prerequisite for any paving: it guarantees the adhesion of the mortar or adhesive bedding, distributes the concentrated loads to the underlying layers avoiding local yielding and alterations, reduces the risk of fractures or cracks and preserves the integrity of the paving over time.
Example section view of a roadbed