- Features and facts from the history of the material
- Suitable architectural styles
- Insulation system and suitable types of substrates
- Open plane cladding
- Base / plinth finishing
- Working with architectural elements
It is becoming more and more difficult to get a presentable and outstanding appearance of the facade. If it is decided to bypass the traditional finishing methods, pay attention to the Dagestan shell rock. We will tell you about the intricacies of working with this material and reveal the secrets of the cladding process.
Features and facts from the history of the material
Dagestan shell rock is a very popular material for external and internal decoration in the countries of the Caucasus and the Middle East. In structure, the Dagestan stone is very similar to ordinary building shell rock, but it has a denser structure, due to which it lends itself well to precise cutting and grinding.
In Dagestan itself, the stone is not called Dagestan, but they can be called Akushinsky, Derbenstky, Rukelsky, etc. depending on the region of origin. Although most varieties of such stone are represented by shell rock, limestone and dolomite are also mined in some deposits. The appearance of different types of stones can be very different, but it inevitably gives the building a special oriental flavor.
The uniqueness of this material is given by its structure: for thousands of years of being in the rocky depths, the shell rock has been well mineralized, while weak sections of the layers have collapsed under the influence of erosion. As a result, it became possible to cut solid, strong and at the same time lightweight blocks with excellent heat-saving properties. At the same time, the Dagestan stone has an impressively varied palette of colors: from sandy and almost white to pink, ivory, gray and rich beige.
In construction, the Dagestan shell rock has been used for a very long time. Take, for example, the most ancient citadel of Naryn-Kala: although this part of the Derbent fortress was built thousands of years ago and now belongs to the class of ruins, many sections of the walls made of shell rock have retained their original appearance. Traces of the use of the Dagestan stone are everywhere caught the eye of tourists traveling in the mountain villages of the Caucasus: from ancient watchtowers to modern residential mansions and administrative buildings.
Suitable architectural styles
Dagestan stone as a building material accompanied the architecture of the peoples of the Caucasus at all stages of its evolution. Starting from small sakel settlements of Rutul settlements and ending with later buildings with high cultural value – mosques, libraries and fortifications.
The culture of the Caucasus was influenced by many ancient peoples: from the most ancient Roman Civilization to the later ones: the Tatar Khanate and other states of the Islamic world. The most recent impact on cultural heritage has come from the Soviet Union and Russia. Tellingly, the architecture of mountain dwellers has always organically adapted to new types of buildings, builders have successfully used and are using local materials in buildings of completely different types.
Due to the time-tested ability to adapt to various architectural solutions, cladding with Dagestan stone will look appropriate on most private residential buildings in all corners of the immense. This finish looks good with small windows, when there are open high gables of the roofs and a solid plane of the walls from the basement to the wind boards. In general, the moderate color tone of the stone makes the finish light and discreet, does not attract undue attention..
Dagestan stone is also great for a more elaborate facade design: it is quite easy to make crowns and cornice strips, figured elements of rustic stones, balustrades, columns, pilasters and slopes from it. Almost all of these products are available in the assortment of Dagestan stone suppliers; elements of especially complex shapes can be made to order.
Small shades of oriental style will be quite appropriate for both modest one-story buildings and large mansions with terraces on the upper floors. The category of exceptions can be, perhaps, houses whose design can be called futuristic, however, for them, such a stone finish will be quite appropriate in landscape design.
Insulation system and suitable types of substrates
The technique of laying Dagestan stone is in many ways similar to working with dolomite or textured sand concrete. But there are a number of not entirely obvious subtleties, most of which relate to the formation of the correct wall cake and the assessment of the compatibility of dissimilar materials.
To begin with, the Dagestan stone loads the load-bearing system of the facade quite heavily. The load from the cladding plates is at least 40-45 kg / m2 and can be significantly higher depending on the thickness and density of the stone. Of the materials for insulation, only properly glued extruded polystyrene foam and hardened basalt wool with a density of 120 kg / m can boast of resistance to such loads3. Such mineral slabs for external insulation are quite problematic to acquire, and very careful observance of the technique of their installation is required. The risk of failure of such a project is extremely high, therefore a very rare contractor will take up the sticker of the Dagestan stone on the insulation.
Basically, lining with shell rock plates is carried out on solid foundations. This does not mean at all that when using Dagestan stone, the house cannot be insulated, but it is somewhat more difficult to do this than when using more popular types of facade decoration. The most suitable are walls made of warm ceramics and porous concrete blocks. If necessary, their adhesion can be easily increased by plastering on a polymer mesh. Using frost-resistant glue, the facade will retain its durability even in the northern regions of Russia.
For stone houses made of small-sized elements, walls of a well or composite type are most preferable. This method of constructing enclosing structures is very versatile for preparing the facade for finishing with Dagestan stone; it can even be used for frame buildings. But there are a number of mandatory requirements: the presence of a protrusion of the required thickness on the outside of the grillage or tape, careful calculation of moisture accumulation, sometimes a ventilation duct device in the composite structure is necessary.
Open plane cladding
Due to its porous structure, the Dagestan shell rock has excellent adhesion, therefore, the adhesive mixture must be selected according to the material of the rough preparatory facade finish. As practice shows, without preparatory plaster, it is possible to glue the shell cladding on porous concrete, silicate and ceramic backing bricks, wood concrete or cinder block. Materials such as PCB or clinker bricks have low hygroscopicity, so it is better to prepare walls from them with reinforced plaster. Laying stone cladding on the plaster layer requires packing a reinforcing mesh, the cell of which is 1.5-2 times smaller than the long side of the stone used.
There is an almost unlimited number of techniques for laying the Dagestan stone when forming the facing layer. The final coating may not have seams at all, since the accuracy of cutting shell rock tiles is quite high. This is usually done when there is significant color variation in the delivered batch, as a result, a beautiful iridescent surface is formed..
If the lot of the facing stone is carefully selected in color, you can make the appearance of the planes more “noisy” and interesting by highlighting the seams. This is done by combining a stone with a chamfer and a straight unedged end. Visual jointing can be formed only on horizontal joints, including those with a pass in several rows, or also on vertical ones. Naturally, this method of cladding requires more careful preparation and calculation of the material..
Base / plinth finishing
Facade cladding is not limited to filling flat areas, although even these can be arranged with a high degree of variety. For example, one of the most effective uses for Dagestan stone is dividing the wall into vertical stripes using narrow pilasters and filling the space between them with diagonal masonry with visually embroidered seams. What can we say about the need for the correct arrangement of abutments at the corners, basement and under the eaves overhang of the roof.
Finishing with Dagestan stone looks the most elegant when contouring the facade with relief elements. Traditionally, the outer and sometimes the inner corners are decorated with rusts. For these purposes, manufacturers supply wide stones that are laid in vertical stripes with a small indent in the absence of a chamfer or close to one if there is one. With straight edges of stones, their joints converging at the corners are formed by an oblique undercut.
The mating with the protruding base and the final top row is easiest to perform with straight small-sized elements that form curbs during horizontal sequential laying. Since the size and weight of such stones is somewhat larger than that of ordinary ones, they need at least a small support board from below so that the element does not slip until the glue sets. In the device for the abutment of the base, it will be enough to remove the flat starting plane with plaster and lay the first row of curly elements. But the final row is laid only after finishing the wall plane, while the upper row elements must be pre-cut to the desired height.
Working with architectural elements
Dagestan stone provides ample opportunities for experimentation and the embodiment of architectural design delights. And although an ordinary builder very rarely has complaints about the pretentiousness of the facade, standard additional cladding elements can be extremely useful. In addition to the already considered linear elements for the formation of cornices, curbs and window sills, wedge-shaped ones are widely used, intended for laying out arches and vaults of niches, and brackets and key stones are also available from most suppliers..
Balusters and handrail stones can be purchased to equip terraces. Columns and columnar pilasters are made of half-rings, the inner cavities of which are filled with lightweight concrete. The joints between piece products are usually sanded after completion of work: unlike ordinary cladding, relief elements have practically no visual joints.
After finishing the cladding, the facade is given time to dry. For sunny summer weather, this period is 3-4 days, in the autumn-spring period, the hardening of the glue can take up to a week. One of the prerequisites for the correct cladding with Dagestan stone is the subsequent treatment of all surfaces with a water repellent.
Usually it does not change the color of the finish, but it can be tinted if it is necessary to smooth out the uneven color of the stones or to give the facade a non-standard shade. The need to use a water repellent is due to the low frost resistance of porous shell rock, artificially imparting water-repellent properties to it ensures the safety of the finish for several decades without any maintenance, prevents its darkening.