Natural stones emerge as the best-known building material, which has been the basis of building materials since the beginning of time. These natural materials, which have completed their evolution over the centuries are geologically inherited. Most of the natural stones, which we see frequently used indoors today, are actually excellent candidates for exterior cladding in terms of strength and durability. It also doubles the value of projects with its aesthetic appeal and sense of luxury.
We collect the natural stones used in exterior cladding under 3 main groups according to their formation conditions. These are sedimentary rocks such as limestone, travertine and sandstone, metamorphic rocks such as slate, quartzite and marble, and finally igneous rocks such as granite.
Architects have to consider a number of factors when creating their projects, choosing materials and methods, and choosing the best type of stone.
Factors such as the purpose of use, the size of the project, the method of application of natural stone coatings, the durability and hardness of the stones, the level of workability, the response to climatic effects, homogeneity, polishing features, absence of cracks, color and texture properties are among the issues to be investigated.
Marble: Rocks with carbonate composition, such as limestone dolomite, which undergo metamorphism and carry traces of metamorphism, are called marble. With a strong historical background, marble was once the indispensable material of famous architects and has been the main hero of countless architectural wonders of the world. We frequently come across the use of marble in ancient temples, palaces, city walls, stadiums and public theaters.
Today, we see less use of marble as an exterior cladding material. The most important reason that directs architects to different natural stones or materials is undoubtedly that marble is relatively more expensive and some cheaper alternatives have been discovered. However, some architects, who know that marble is a status symbol, still prefer marble as building covering material in their prestigious and spectacular projects. You ask why? Because marble promises an indestructible, solid, majestic, smooth and luxurious appearance.
For the application process, dry hanging model should be preferred. This is the most reliable method in terms of both durability and convenience for future restoration processes. Technical calculations for marble, which is a heavy material, must be done with great care. Although it is a material that is resistant to atmospheric effects, its physical and technical analyzes should be done beforehand to prolong its life and ensure its freshness for many years. Details such as hardness, water absorption, expansion, etc. should be determined on a product basis. If the joints and anchorage are carefully calculated and protective solutions against water are taken during the application, water intake into the stone will be prevented. Marble, an important material for sustainable green lives, enables us to gain advantages in energy saving with the natural thermal insulation it provides. Selecting A quality stones for the use of marble on the façade and eliminating unwanted yellow veins contribute greatly to the homogeneity of the project. In addition, although we have said that marble is an expensive material, when you consider ir price / performance basis, you will always be advantageous.
Limestone: Limestone, which is the raw material of lime, usually consists of calcium carbonate (CaCO3). According to the classification based on the calcium carbonate ratio in it, the limestone types are listed as follows: very high calcium limestone, high carbonated, calcite, magnesium, dolomitic, high magnesium dolomite.
Limestone, which we frequently encounter in nature in white, beige, cream, bluish gray and brown tones, is an extremely flexible material and its workability is easier than other natural stones. Its texture ranges from creamy and soft to slightly hard-veined. Being readily available, easy to work with, and a good material for fine details makes it a great façade material. In fact, we can say that the most frequently used natural stone as an exterior material in the building sector is limestone. We can see that this stone is frequently used in many public buildings, shopping malls, mass housing, business centers, train stations and banks.
When we compare it with marble, it is possible to say that it is easier to maintain. It is a long-lasting material that is resistant to environmental factors, resistant to heat and cold. We would like to remind you that the Pyramid structures in the Egyptian city of Giza are limestone and have been able to maintain their integrity until today. Considering the weight of the material, it is necessary to use it as thin plates in multi-storey buildings.
Limestone used on building facades or on the outer walls of similar structures show a permeable, matte and spongy feature. This stone is especially preferred on the airy surfaces of constructions.
Travertine: Travertine is a chemical sedimentary stone formed as a result of the precipitation of calcium carbonate in cave cavities or places where calcium bicarbonate underground waters rise to the surface. They are the steps formed by the precipitation of lime, usually near hot water sources and in areas where calcium carbonate waters spread and flow. The best examples are in Denizli-Pamukkale and Yellowstone. It has been a preferred stone type in buildings for many years. It is one of the most frequently used stones in modern architecture.
Travertine is found in a wide variety of colors such as ivory, beige, brown, walnut, red, gray and yellow in nature. It typically has a strong plane. Its porous and spongy structure makes it a lighter building material compared to other natural stones, and it does not lose anything from its strength.
Travertine, which is relatively easy to work and process due to its structure, provides good acoustic and heat insulation. They can be used for many years without any deterioration. It is highly resistant to environmental conditions, especially to the effects of rain. Travertine, which is intertwined with water due to its natural structure, is one step ahead with its water-tolerant feature compared to other natural stones. Due to its abundance in nature, its price is more suitable than others. While there are architects who use travertine alone to achieve a flat and clean appearance in building façades, there are also architects who create decorative images by mixing it with other natural stones such as marble.
Granite: Granite is an igneous rock type rich in alkali and feldspar, formed from crystalline minerals, formed during the cooling of molten rocks. Granite, which is famous for its durability, homogeneity in color and being one of the most common stones in the world, has been used as an exterior coating material for many years. It has a very hard structure and is a much more difficult product to process when compared to other natural stones, but it is a stronger material than all of them. Granite is often used as a facing stone in public and commercial buildings and monuments.