Sandstone is one of the oldest building materials donated by nature itself. The legendary Egyptian pyramids, which have survived for more than one millennium, are built from this stone. In modern construction, sandstone is also widely used, primarily for facade cladding. Such buildings look very attractive, and in addition, they have a number of advantages in terms of operation. True, before choosing sandstone as a facing material, it is necessary to study the features of the stone and the rules for working with it.
Yellow limestone facade - sandstone
Sandstone for the facade
The main component of the stone is densely compressed sand. In addition, its composition includes small shells, clay and other organic compounds - their ratio depends on the specific type of sandstone. For example, shell rock, as the name suggests, is an accumulation of small shells that create a porous material with cells, while marl sandstone consists mainly of clay and calcium carbonate. Stone is mined in almost all parts of the world and is used in any form, including chips, slabs for facing surfaces (processed or untreated), crushed stone, etc.
Compacted sand sedimentary rock
|Thickness||Strength||Frost resistance||Water absorption||Radioactivity|
|10-50 mm||800 kg / cm3||200 cycles||About 5%||Missing|
In other words, sandstone is environmentally friendly, safe for human health, which has high strength and resistance to negative factors.
Another advantage of sandstone is the wide range of colors, making it easy to match finishes to any style and landscape.
Natural sandstone is a unique natural decorative building material that has a reputation as an elite
Like any other facing material, sandstone has a number of advantages and disadvantages. The positive aspects of sandstone facade finishing include:
Sandstone does not have a negative effect on the human body, does not react with substances contained in other building and finishing materials
Natural stone is a very good material, and when used correctly in design, it cannot be replaced by any other material
Unlike granite and marble, sandstone does not require complex work, but is simply laid on a cement mortar
There are also disadvantages to the material, although there are not so many of them. Firstly, due to the rough surface of sandstone, it is impossible to polish it to smoothness, and, secondly, in terms of strength, it is inferior to a number of other natural stones (for example, granite and marble).
If we talk about colors, then most often in nature there is a stone of gray-green hue, which is the cheapest. Using the firing technology, sandstone of a reddish and brown hue is obtained - it has a higher cost, but at the same time it looks very attractive and is more durable. But the yellow color of the stone suggests that the material should not be used in facade work, since it is not sufficiently compressed and has a low density.
Tumbling sandstone slab thickness 2 cm color terracotta-red
Natural facing sandstone, yellow
To determine the quality of the sandstone, you need to lightly hit one a stone on another - if a dull sound is heard, it means that during operation the material will exfoliate into separate layers and quickly fall off.
As a material for cladding facades, sandstone slabs of regular geometric shape are usually used.
In addition, you can purchase unusual types of stone, including "torn", flaky and sawn sandstone - with their help you can implement any design solution and create original masonry.
High-quality sandstone is notable for its purity, not because it was washed after mining, but because it was probably taken from the lower layers that are not in contact with the ground
To make sure the quality of the stone, you should carefully examine it. Quality material is clean and smooth, as it is extracted from deep layers of the soil. Layering at the ends indicates that the sandstone has been exposed to the weather, so it can quickly crumble.
As mentioned above, sandstone has a wide variety of colors and processing options, which makes it possible to create cladding of different types and styles.
Facade cladding for brickwork
Among other things, sandstone can be combined with other types of natural stone and other finishing materials , as well as create ornaments and unusual motives from it.
Before proceeding with facing the facade with sandstone, you must choose the correct technology for performing the work, since each of them has its own characteristics.
It is possible to cover the entire structure with a stone, as well as its individual fragments, if it is provided for by the design project.
If the full cladding technology is used, the following features must be considered:
Partial façade cladding also gives a lot of room for imagination: you can highlight individual building elements, add interesting details or create a 3D effect using slabs of different thickness.
Since sandstone is a fairly soft material, it is easier to work with it than with other types of natural stone, and for laying you need a simple set of tools.
Sandstone glue can be mixed by hand, but using a special mixer will create the most homogeneous mixture.
Mixer drill bit
Sealant gun, closed for tubes with smooth stem
Used to create a clean visual line for the cladding.
Angle grinders (grinders)
Best for laying sandstone use a mortar of cement and sand (for spraying) and a mortar of cement, sand and glue - for example, Ceresit glue mixture is often used.
Glue for natural stone - Ceresit CM 117
Approximate proportions are as follows: two parts of the glue mixture are taken for two parts of the cement and sand.You can lay the material on a regular glue solution, but many experts believe that in this case it will hold up much worse. The amount of the mixture may be different depending on the chosen laying technology, but you should not save on it.
The fact is that sandstone is characterized by low water absorption, therefore, a sufficiently large amount of mortar is needed for a strong and reliable facing.
It is best to mix the solution with a mixer, so you will avoid lumps
The calculation of consumables is performed after drawing up a design project of the facade. It is necessary to determine the total area of the facade, taking into account the protruding elements and openings, and then divide the resulting figure by the area of one unit of material. In addition, the length of all outside corners should be summed and divided by the length of the material unit.
Add 10-15% to the total figure in case of additional costs.
In order for sandstone masonry to be durable and strong, it must first be well cleaned. For stone that has undergone preliminary heat treatment (the so-called fried sandstone), rinsing with running water will be sufficient. But the raw material, that is, the "wild" stone must first be soaked and well cleaned with a brush. Soaking not only ensures the cleanliness of the material, but also contributes to the fact that excess salt leaves it, and "salt" will not form on the surface.
Rinse the stone
If the surface of the stone is covered with a thin layer of clay, more serious cleaning is required, using an acid, otherwise the facing will quickly crumble ... An excellent result is also obtained by cleaning with a pressure washer, which not only cleans the material well, but also knocks out weak parts.
Once the sandstone has been prepared, it should be laid out on a clean foil to map out the future masonry.
Sandstone prepared for laying
An equally important step in facing the facade with sandstone is appropriate surface preparation. The wall should be well checked for strength, preferably by hand, that is, knock on it for damaged or crumbling elements. They will need to be beaten off with an ax or a perforator, otherwise they will eventually fall off along with the cladding. If the facade is finished with old plaster, it is better to remove it, as it will significantly reduce the adhesion of the surface to the stone.
Small cracks and chips formed during the preparatory work can be repaired with an adhesive mixture, and deep ones - with cement sandy solution. Next, you should well clean the wall from dust and grease stains with a broom or brush. The surface should be as clean, even and firm as possible.
The next question that will need to be resolved is the need to treat the walls with a primer.Some experts recommend treating only loose surfaces with such compositions, while others say that such a procedure is necessary in any case, so a decision should be made based on the characteristics of the facade.
The best option is a deep penetrating primer, which is applied with a large brush so that it covers the entire surface, including small gaps. On a porous material like shell rock, the primer must be applied in two layers, since the first one is completely absorbed into the pores. After the primer has dried, the wall should be slightly moistened for better adhesion to the stone.
An important condition is the temperature regime - the sandstone is laid at temperatures from +5 to +30 degrees, and work is recommended perform at the end of summer, when the temperature and humidity are not too high. It is impossible to veneer the facade with sandstone in frost, since in such conditions the solution will not be able to dry properly.
Deep penetration primer
Laying the material is a fairly simple task, but requires knowledge of some rules and subtleties of work. There are several technologies for cladding buildings with sandstone: wet and ventilated facades, mechanical installation, and ordinary decorative masonry.
After that, the wall should be leveled with a sand-cement mortar and wait for it to dry. In order to ensure 100% strength of the fastening of the material to the facade, additional wire can be used. On the back of each stone, a slot is made into which a metal wire is laid. When installing sandstone on the surface, the wire is threaded through the reinforcing mesh and provides additional strength to the cladding. This type of cladding is optimal for fixing heavy, massive slabs and stones that do not adhere well to the adhesive solution.
The advantage of a ventilated facade is the presence of a space between the stone and the wall surface, along which air flows. Such a system provides additional insulation and at the same time ventilates the masonry, preventing it from damp.
Laying the sandstone itself, regardless of the technology chosen, looks like this.
Step 1. Lay the slabs or stones on a clean dry surface, creating the desired pattern (this step should not be skipped, otherwise the work may be delayed).
Step 2. Prepare the spatter and adhesive mixture using a mixer wedged into a drill at low speed.
They should not be too thick, but not too liquid, so that the mass does not slide off the wall. If a mixture of sand, cement and glue is used for the work, it will be usable within two hours.
Step 3. Laying starts from the bottom row. In order for the material to lie flat, you need to pull a special cord and align the first plate along it.
Depending on the type of sandstone, it can be laid close or with jointing, that is, with a certain distance between slabs or stones. In order for the distance to be uniform, it is necessary to use spacers or "crosses", which are removed after the mortar has hardened.
Step 4. First, the wall should be treated with a cement-sand mortar, and at a time it is better to process no more than 0.5 m 3 surfaces, since the solution has property to freeze quickly.
The thickness of the layer depends on the thickness of the tiles - if they are thin, it makes no sense to apply a thick layer. The mixture is applied with a spatula, rubbed lightly into the wall and leveled well.
Glue is applied with a spatula, after which a relief is made with a comb
Step 5. Take a stone or slab, apply the adhesive mixture to the back side and spread it well with a spatula.
Apply the mixture to the stone
Press it to the surface, swinging slightly so that there are no voids filled with air under the sandstone.
For reliability, you can slightly knock it out with a rubber mallet. If the solution is on the front of the stone, it must be immediately removed with a damp sponge, as it will be problematic in the future, and the remains of the solution on the facing will look sloppy.
Hit the stone with a mallet
Step 6. Lay out the following slabs in the same way, trimming them if necessary grinder until you get one row, which should be aligned with the mounting cord. After laying 2-3 rows, work should be paused and the solution allowed to dry, otherwise there is a risk that the lower rows will slide under the weight of the upper ones.
Laying sandstone with your own hands
Facing the walls with sandstone
It is important to note that it is better to finish the sandstone cladding in one day.If it takes more time to complete the work, it is recommended to lay out 1-2 walls at a time, but in no case stop in the middle.
Grouting between the sandstone slabs is necessary to ensure that the cladding looks neat and attractive. Seams can be rubbed using special mixtures (the packaging should indicate that they can be used for natural stone), which are available in liquid and dry form.
The best quality grout is provided by a liquid mixture, but it is quite difficult to work with it.
Another option is to fill the joints with an adhesive mixture that was used to install the material. Its disadvantage is that after the solution dries, deep cracks appear on its surface, where water will subsequently accumulate.
Filling the joints with the adhesive mixture that was used to install the material
Grouting is performed after the cladding is completely dry in dry weather: the grout mixtures dry out for about 10 hours, and it is very important that moisture does not get to the surface during this time. The seams are filled with the solution with a gun or syringe so that it protrudes slightly above the seam surface.
After the mixture has slightly "set", it is necessary to smooth it with light movements and remove the residues from the surface of the stone.
Example of execution using a pastry bag
Using a sealant gun
When the grout is dry, rinse the stone with a brush
As a final touch, sandstone can be treated with a special water-repellent varnish - it will protect the facade from weather factors and will give it a beautiful shine.
Cover the stone with varnish
Grout for stone
During operation and regular temperature changes typical for some regions, sandstone can delaminate and crumble ...
Treatment with water-repellent and protective solutions can reduce the impact of negative factors on the material, but is not a panacea. If defects, chips and cracks appear on the surface of the stone, it is recommended to immediately repair them, since over time the scale of destruction will only increase. For these purposes, there are special adhesives that should be used to fill the resulting gaps.
Another feature of sandstone is that after a while, the seams of the facing may start to whiten, as various impurities and salts will be released from the material. It is quite difficult to get rid of this phenomenon - it is much easier to prevent it by cleaning the material well before laying.
As for regular maintenance, the sandstone facade does not require any special measures - it needs to be washed from time to time with plain water. The easiest way to do this is with a high-pressure car wash (some of the units even have special nozzles for washing natural stone). Before carrying out the procedure, it is better to cover the facade with a broom, since sand and dust often settle on the stone, and the abrasive particles they contain under the pressure of water can leave the smallest scratches on it. As a result, the surface will look dull and discolored over time.
Despite the emergence of new facing materials, sandstone, like any other natural stone, will always be popular among owners of private houses.
The correct laying of the material on the walls of the building, as well as the proper care of its surface, are the key to the fact that the facade will look impressive and attractive for a long time.
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