Mechanical Stone cladding is a process that deals with the application of a thin layer of real or simulated stone to a building surface or other structure made of a material other than stone for beautification and aesthetic purpose. Stone cladding is found to be applied occasionally to concrete and steel buildings as a part of their original architectural design.
Cladding means the application of one material over another to provide a skin or protective layer. In the construction sector, the cladding is used to provide an extent of thermal insulation and weather resistance, and to improve the beautification of the buildings.
Natural stone cladding on concrete is generally carried out with mechanical fixing arrangements using expansion bolts and is termed as dry fixing.
The following seven points are very important and should be taken into consideration when designing a fixing system for natural stone cladding on building surfaces:
- Dimensions of the stone
- Position size and
Nature of Cavity
- Installation of horizontal or vertical joint
- Load carrying capacity of Structural
- Height of façade
- Expected dynamic loads such as wind and seismic loads
- Other design criteria of the project
Purpose of mechanical stone cladding
Typically, the stone cladding is used:
- To impart a stone finish to an existing structure.
- To create a stone finish at a lower weight, and for the purpose of reducing structural support
- To allow faster with a lower cost of installation.
- The advantage of off-site manufacturing, with minimum site construction.
- To reduce waste.
Mechanical stone cladding process
The mechanical stone cladding is carried out by quarrying natural stone and grinding or milling the stone into thin pieces or particles. A range of sizes, thicknesses, shapes, and patterns can be generated according to the design requirement. Cladding can be applied either as single stone pieces, or as large and bespoke panels fabricated from a number of pieces, such as story-height type panels, or as a shaped part like reveals and lintels.
To tolerate the weight of natural stone, the cladding system should be fixed mechanically to basic structural substrate layers. This can be done using mechanical shelf angles or can be specially-manufactured and designed with special stone clips.
As an alternative, cladding panels can be manufactured by laminating thin pieces of stone onto a secondary carrier panel made by using lightweight concrete. Because the two materials have similar physical characteristics, they can be joint well together as a composite stone piece and provide good weather protective feature.
In the situation of the requirement of very thin stone pieces, about 1 inch thick stone pieces are used, providing a final finish to a structure such as blockwork, this may be termed as a ‘stone veneer’.
There are wide verities of stone cladding are used such as:
- Natural stone tiles.
- Patio stone.
- Pebble dash.
- Stone dressing.
Other design criteria and advantages of mechanical stone cladding:
- 3-dimensional compatibility
- drying time not necessary
- 304 and 316 stainless steel grades can be used for mechanical clipping
- layout sheets preparation with detailing
- complete façade cover with every designed anchor
Alternate cladding procedure use:
- timber stud type frame
- waterproof layer as a barrier
- fiber type cement sheets
- expanded metal mesh
- mortar scratch coat.
Subsequently, a mortar mix is normally applied for affixing the stone cladding to the wall. In the USA, a typical installation uses plywood backing as an alternative to fibre cement sheet.
Mechanical stone cladding is a simpler procedure of cladding, requires less time and is a cost advantage compared to the conventional stone cladding.