Sandstone for the facade: characteristics of the stone and installation instructions

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.

What is sandstone?

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.

Sandstone specifications

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.

Sandstone in facade works: advantages and Cons

Like any other facing material, sandstone has a number of advantages and disadvantages. The positive aspects of sandstone facade finishing include:

• stone availability, especially in comparison with marble or granite;
• sufficiently high strength;
• attractive appearance and interesting structure ;
• light weight, due to which the sandstone finish significantly reduces the load on the building foundation;
• good heat and sound insulation characteristics.

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).

How to choose sandstone?

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.

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.

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.

Prices for various types of sandstone

Sandstone

Types of sandstone facades

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.

1. Facing under the masonry from the die. In terms of cost, this option is the cheapest, as it allows the use of raw stone, but its implementation requires some skill and patience. The difficulty lies in the fact that for facing the facade you will have to choose stones of different sizes and shapes so that there are no large gaps between them.

   

   Facade cladding for brickwork

2. "Castle" cladding . It is a decoration of the facade with tiles with a convex, embossed surface, as a result of which a flat surface is obtained that imitates the masonry of medieval castles.

   

   Castle cladding

3. Plateau cladding . For cladding of this type, you need to take rectangular or square tiles with processed ends and select them in size so that you get a solid surface.

   

   "Plateau" facing

4. "Assol" facing . The most original and unusual option, which differs from all of the above in volume and relief. It is carried out from thin long elements and is considered one of the most difficult to perform: stones of different thicknesses must be selected so that the differences look holistic and harmonious.

   

   "Assol" cladding

5. "Rondo" cladding . Visually, such masonry resembles a panel made of rolled sea pebbles, it looks very impressive and is easy to perform. The only drawback is the rather high cost of the material, since a special stone with processed ends is needed to complete the work.

   

   "Rondo" cladding

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.

Step-by-step instructions for facing the facade with sandstone

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:

• do not use too small stone during work, otherwise the appearance of the facade will ripple in the eyes;
• if the cladding implies open seams, do not use too large slabs, otherwise the visual effect will worsen;
• it is allowed to use tiles of different sizes, since in this case the walls will acquire an original and unusual look;
• sandstone is optimal for facing stone and brick houses, but for a tree it is better to choose another option - firstly, the stone is held on wooden surfaces very bad, and, secondly, the facade finished in this way does not look very attractive;
• if the building is new, it is better to start work at least six months later, so that it has time to shrink.

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.

Stage one. Preparation of tools and materials at hand

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.

1. Bulgarian . Required for cutting material, and cheaper and simpler cutting discs can be used than is necessary for ceramic products.

   

   Angle grinder

2. Notched trowel . The surface of the stone is not uniform, so it is best to use a notched trowel to distribute the adhesive evenly.

   

   Notched trowel

3. Mixer for mixing adhesive mixture .

   Sandstone glue can be mixed by hand, but using a special mixer will create the most homogeneous mixture.

   

   Mixer drill bit

4. Sealant gun . It is recommended to purchase a gun or syringe for filling the joints if a large area is to be covered with sandstone. In the case of small volumes of work, this will be impractical and too costly - it is better to use a regular plastic bag or even a pastry syringe.

   

   Sealant gun, closed for tubes with smooth stem

5. Cord .

   Used to create a clean visual line for the cladding.

Prices for angle grinders (grinders)

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.

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.

Step two. Preparation of stone

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.

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.

Stage three. Surface preparation

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.

Prices for deep penetration primer

Deep penetration primer

Stage four. Laying sandstone

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.

1. Wet facade technology . The main feature of this technology is that, before facing, a reinforcing mesh must be laid on the surface, securing it with dowels.

   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.

   

   Wet facade

2. Mechanical cladding . Such fastening of sandstone is not very popular in Russia, but in the West it is used quite often. Laying is done using metal elements - a slot is made on the back of the stone, into which fasteners are inserted. Additionally, the material can be treated with glue, the main advantage being that the consumption of the glue mixture will be much lower than with other facing methods.
3. Ventilated facade .

   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.

   

   Ventilated facades

4. Decorative masonry . The simplest, but not always reliable way of facing facades, as it involves the use of raw elements. Accordingly, installation requires precise adherence to the proportions of the adhesive solution and the laying technology.

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.

Step 5. Take a stone or slab, apply the adhesive mixture to the back side and spread it well with a spatula.

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.

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.

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.

Stage five. Grouting and finishing

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.

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.

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.

Prices for grouting materials for stone

Grout for stone

Restoration and maintenance of a sandstone facade

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.

Video - Sandstone cladding