Alabaster is one of the oldest building materials, known to masters for more than 5 thousand years. And it is still in demand, despite the emergence of numerous dry building mixtures and stricter requirements construction industry. Why?

Plaster = alabaster?

People who are not involved in construction sometimes have confusion in terms: some people think that gypsum and alabaster are synonyms, everyone simply calls it as they are used to, while others think that alabaster is the best and highest quality variety of gypsum.

Some even believe that alabaster is a stone from which statues are sculpted, and when crushed it is used for finishing work, so it is harder and whiter than plaster.

So what is alabaster?

This is really a “subspecies” of gypsum. Like building gypsum, it is obtained from a natural mineral - gypsum stone, both of them are calcium sulfate, onlythe first is dihydrous (CaSO4 2H2O), and alabaster is hemihydrous (CaSO4 0.5H2O) .

The mineral is crushed and then fired at a temperature of about 180C.

The grind of alabaster is finer than that of building gypsum, and therefore this material has less ductility, but greater hardness.

Also his unique feature are the drying times - alabaster mortar sets on average in 5 minutes, that is, much faster than other building mixtures.

These properties narrow the range of applications of alabaster to construction and finishing works, while gypsum can be used in many industries, including medicine, jewelry, casting, art, etc.

Characteristics and types of alabaster

The main average characteristics of alabaster are presented in the table below:

Since one of the main features of the mixture is the rapid development of strength, three types of alabaster are distinguished according to the speed of hardening:

Benefits of alabaster

• Fast and smooth! Thanks to the speed of setting, the surface can be leveled literally in minutes, and after an hour, and even then if taken with a reserve, it is already ready for further processing.
• Alabaster solution has high adhesion and fits perfectly on almost any prepared surface
• Frozen alabaster has good strength characteristics And. To this day, elements of palaces and temples that are more than 5 thousand years old have been preserved, and they are in excellent condition. When dry, the material does not shrink and is resistant to cracking
• Hardened Alabaster absorbs noise, therefore it can be used as auxiliary material for sound insulation. 6 hours exposure to open fire- this is exactly how much alabaster can withstand without significant deformation. It does not burn itself and prevents the spread of flame.
• In the composition of the material no chemical additives, it is environmentally friendly and can be safely used in bedrooms, children's rooms, etc.
• Democratic price compared to similar dry construction mixtures.

Application of alabaster

Due to the characteristics of the material, the range of applications of alabaster in construction is wide: it is relevant for the production of drywall and is in demand professional builders, and is also often used by private owners for minor repairs.

1. Correcting cosmetic defects in walls, ceilings and gypsum plasterboard/gypsum board surfaces. Alabaster mixture is traditionally used to repair various chips, dents, cracks, etc.
2. Preparing surfaces for finishing The alabaster mixture is excellent for puttingtying walls and partitions in rooms with normal humidity; it is used to prepare surfaces for wallpaper of all types, as well as decorative plaster. Some builders even use alabaster in bathrooms, under tiles, but in this case it is necessary that the material is completely hidden by the cladding and not in contact with water. This principle is also true for the kitchen, since alabaster absorbs moisture vapor.
3. Electric installation work Alabaster is an electrician's joy, most comfortable material, allowing you to quickly fix the cable in the wall without the risk that it will move while the mixture dries. In addition, many people use it when installing socket boxes, because... even if the plug is roughly pulled out of the socket, the structure, thanks to the hardness of alabaster, is guaranteed to remain in the wall, which sometimes more expensive and modern dry mixes cannot provide.
4. Interior decoration. When decorating rooms with stucco, a specific problem often arises: cast gypsum elements have considerable weight and therefore must be firmly fixed to the base. This is especially true for ceilings. And alabaster in this case - perfect option. It will also come to the rescue for masking and repairing small flaws in stucco molding and is indispensable for restoration work.

Preparing for work

When working with alabaster, half of the success depends on the quality of preparation, namely, on the selection of containers and tools.
To make the process easier, consider the following principles.

• There are no metal containers right away! Alabaster will stick tightly to the iron walls, which means loss of material, inconvenience and damaged container. Plastic dishes fits better, but most a comfortable option It is, after all, rubber: the solution does not stick to the springy walls, and after finishing the work, the dried residues can be easily shaken out; to do this, it is enough to squeeze the mold several times and then turn it over. In addition, if desired, construction stores You can purchase special buckets for working with plaster.
• The container with the remaining solution is not immediately available! The dried solution accelerates the hardening of the new batch being mixed.
• As for the spatula, they are very convenient modern instruments from plastic or rubber, the mixture does not stick to them. But a classic steel spatula is also quite suitable, preferably a new one: according to the observations of some craftsmen, rust accelerates the setting of the already fast-hardening solution

For small volumes of mixture

It is convenient to seal small portions of alabaster in nylon buckets or compact rubber containers. Often builders use halves of ordinary children's balls of suitable diameter.

A spatula is optimal for stirring “small doses” of the alabaster mixture.

For large volumes

Plastic or rubber bucket line with a single piece of cellophane, dense and without holes, pin the “tails” to the edges of the container so that the polyethylene does not move during stirring; After use, the film is simply removed from the bucket and thrown away.

It is convenient to stir the solution with a construction mixer, or, if it is not available, with a drill with an attachment.

Mixing and working with the solution

Here it is important to answer three questions: in what proportion to mix, how exactly to mix and what nuances should be taken into account when mixing?

Actually, the proportions depend on the purposes for which the solution is planned to be used. SNiP recommends the following ratios:

In order not to ruin the material and get a high-quality solution, stick strictly to technology.

• remember, that the mixture is added to the water, but in no case vice versa!
• Powder needed sprinkle gradually like flour in pancake dough, and mix thoroughly until the mass is homogeneous.
• The correct putty solution has the consistency of mousse or yogurt.
• If the solution begins to harden, and you didn’t have time to use it up or do what you planned just throw it away, without trying to “reanimate” by adding water. With alabaster, the principle “it died like that” is 200% correct; the set solution is no longer suitable for anything.
• When applying the solution, keep in mind that when it dries, the material increases slightly in volume.

Tips from the experts:

Theory and SNiPs- this is, of course, good, but in practice, alas, the dry mixture can behave differently, it all depends on the brand and even the batch. Therefore, before closing the entire required volume, conduct a test with 100 grams of material.

For shuttering use cold water .

When mixing the solution, it is certainly worth strive for uniformity. However, overdoing it is also fraught: there is an opinion that mixing too long and thoroughly, especially with a mixer, disrupts the structure of alabaster, as a result of which it loses strength.

How to extend the life of alabaster solution?

Beginning craftsmen, as well as private owners without experience or construction skills, when working with alabaster, often wonder whether it is possible to slow down the hardening of the solution a little.

And there really are such ways. Some of them are quite scientific, some relate to “folk” methods, which, nevertheless, have shown themselves to be quite good in practice.

Method 1. Bone glue.

A good old remedy, approved by more than one generation of builders. When mixing, add any bone-based glue, be it slightly diluted painter's or carpenter's glue. The main thing is the dosage: 2% of the total weight of the mixture.

Method 2. Citric acid

The recipe is as follows: for 0.5 cups of alabaster, take 4-5 grains citric acid and throw into cold water while mixing. However, masters note that, despite its apparent simplicity, the method is not universal, since the amount of acid must be selected for a specific alabaster mixture, that is, tests and experiments are required.

Method 3. PVA glue

This is where builders are divided into two camps. Some say that 3% PVA by weight of the mixture gives an excellent result, that is, it extends the viability of the solution almost several times and in the future does not affect its strength in any way. Others object to them - they say that the film that PVA forms on the surface when drying can block the evaporation of water, so that recrystallization and enlargement of sodium sulfate hydrate crystals are likely, and this leads to a deterioration in strength characteristics.

How to choose and where to buy?

It would seem that alabaster is a simple mixture, without chemicals, without plasticizers, take the first package of any brand you come across and go ahead, because it is difficult to spoil the material. However, there are still nuances in the choice.

1. Since alabaster is extremely susceptible to moisture, it must be stored in dry areas. So it is advisable to purchase the mixture in stores, and not in markets, where the tightness of containers often leaves much to be desired, and certainly not in areas where open air
2. Check the integrity of the packaging carefully, because at the slightest violation, there is a chance that the material has partially or completely lost its properties.
3. No matter how simple the alabaster mixture may be, You should choose not only by price, but also by manufacturer: large manufacturers are given priority, since, thanks to well-established and regulated production, they are ready to ensure stability of quality, while for noname brands the quality can “dance” greatly from batch to batch.
4. Give back preference for brands whose packaging indicates the proportions for mixing their mixture, because, despite SNiP standards, recommendations may vary.

Most ordinary buyers do not see any significant difference between alabaster and plaster. In fact, this is far from the same thing.

This is a fine-grained variety of gypsum produced by firing. Most often used in construction and finishing works. According to its properties, it is harder than gypsum. Also to distinctive features This can be attributed to its drying time, which is much faster than that of plaster. That is why, in order to extend the “working” properties of alabaster, many builders mix special additives into the solution.

Distinctive features of alabaster from gypsum

• The solution is white with a grayish tint.
• Working with alabaster is not at all difficult, but with plaster it is more difficult.
• Alabaster contains a smaller amount of molecular water.
• The solution consists of elements of various impurities, such as glue, paraffin, wax and other elements.
• It has a more elastic structure (gypsum has a soft structure).
• When applied to the wall surface, it does not chip or crumble.
• Has a rapid increase in strength.
• Allows you to regulate the humidity in the room.

Scope of application

Gypsum has a wider range of applications. Compared to alabaster, it is used not only as a construction and finishing material, but are also actively used in the medical industry, in particular in traumatology and dentistry.

Alabaster is a quick-drying material, and therefore you need to work with it quickly and without interruptions. Therefore, many builders add special additives to the solution to increase working time. That is why this material is used only in the construction industry. Before you start working with alabaster, the powder must be diluted cold water to a viscous consistency. The amount of solution depends on specific situation. There is no point in kneading alabaster “for future use.”

Alabaster is incredibly popular in the construction industry. It allows you to perform high-quality renovation work. With its help you can eliminate almost any defects and unevenness on the wall surface. The solution can easily be used to cover cracks, chips, seams and holes.

Due to its quick-drying properties, alabaster is suitable for electrical installation work. The resulting mixture is used to cover the grooves and fasten the sockets.

Alabaster is also suitable for interior decoration.

Gypsum, alabaster, lime

During construction and renovation, gypsum or alabaster is often used to finish walls, ceilings, and even floors. What is the difference between alabaster and plaster? These materials are similar in many ways, alabaster is a derivative of gypsum, however, their qualities and properties differ, so that in some cases only gypsum (Rotgypsum) can be used, and in others - alabaster. In this case, you need to know their main characteristics. Perhaps only then will you decide which of these materials will be used. Let's take a closer look at what each material is.

Construction gypsum - what is it?

Gypsum is a natural, environmentally friendly material with excellent binding characteristics, rapid hardening and subsequent strength. It is safe in case of fire. When moisture accumulates in a room, this material absorbs excess and, if necessary, releases it back into dry air. This property makes gypsum a unique finishing material.

Construction alabaster - what is it?

Alabaster is a building material that is obtained after firing crushed gypsum. Alabaster is used to repair room surfaces, and panels and slabs are also made from it. This soft material, it is easy to work with a saw. Like gypsum, it does not burn and is environmentally friendly.

• Quality of building gypsum.
• Quickly sticks to the surface and hardens.
• Withstands high temperatures without destruction.
• Open fire begins to act on plaster after 6 hours.
• Hardened plaster is not afraid of mechanical damage.
• Qualities of alabaster.
• Hardens within 5 minutes.
• Protects against crack formation.
• Levels the surface.
• Soundproofing.
• After drying, alabaster increases in volume.

Alabaster adheres firmly to almost any surface except rubber. In this regard, it is advisable to line the container in which alabaster is diluted inside with polyethylene.

What is the difference between plaster and alabaster?

Compared to the use of alabaster, gypsum is a universal building material. To the touch you can feel that gypsum is softer than alabaster, and it hardens more slowly (about half an hour). The high drying rate of alabaster is not always positive. An additive is often added to dry mixtures and liquid mortars to increase the hardening time. This increases the working time with the solution.

What is stronger: plaster or alabaster?

In plaster mechanical strength higher than alabaster. A serious drawback of alabaster - under It fades due to moisture. It is no coincidence that gypsum is used in different areas, including medicine - it is more environmentally friendly and safe for health, while the use of alabaster is limited to the construction sector.

Application of building gypsum

Gypsum is used as the main component for a wide range of materials: dry construction mixtures, plaster, putty, adhesives. The gypsum itself (Rotgypsum) is excellent for sealing seams, cracks, and irregularities. Natural stucco moldings, cornices, decorative elements interior For interior decoration, gypsum has also found use as a base for decorative stone, which you can even make with your own hands and facing tiles.

Gypsum has been known since ancient times, but has not yet lost its popularity, even many modern materials cannot compete with him. It is used in construction, porcelain, ceramic, oil industry and in medicine.

Description of building material

Gypsum is produced from gypsum stone. To obtain gypsum powder, the stone is fired in rotary kilns and then ground to form a powder. Gypsum is most common in construction.

Walls plastered with gypsum mortar are able to absorb excess moisture and release it when the air is too dry.

Gypsum formula

The name gypsum comes from Greek word gypsos. This material belongs to the class of sulfates. His chemical formula CaSO4?2H2O.

There are two types of gypsum:

1. Fibrous - selenite;
2. Grainy - alabaster.

Photos of gypsum varieties

Selenite Alabaster

Technical characteristics and properties

For all gypsum mixtures specifications have great similarities, let us dwell on the properties and features of building gypsum.

These include:

• Density. Gypsum has a dense, fine-grained structure. The true density is 2.60-2.76 g/cm?. When loosely poured, it has a density of 850-1150 kg/m2, and when compacted, the density is 1245-1455 kg/m2.
• How long does it take to dry? The advantages of gypsum include rapid setting and hardening. The gypsum sets in the fourth minute after mixing the solution, and after half an hour it completely hardens. Therefore, the finished gypsum solution must be used immediately. To slow down the setting, water-soluble animal glue is added to the plaster.
• Specific gravity. Is the specific gravity of gypsum measured in kg/m? in the MKGSS system. Since the ratio of mass is equal to the volume it occupies, the specific, volumetric and bulk weight of gypsum is approximately the same.
• What temperature can it withstand? t melting). Gypsum can be heated to 600-700°C without destruction. The fire resistance of gypsum products is high. Their destruction occurs only six to eight hours after exposure to high temperature.
• Strength. Construction gypsum has a compressive strength of 4-6 MPa, high-strength - from 15 to 40 MPa or more. Well-dried samples have two to three times higher strength.
• GOST State standard gypsum 125-79 (ST SEV 826-77).
• Thermal conductivity. Gypsum is a poor conductor of heat. Its thermal conductivity is 0.259 kcal/m deg/hour in the range from 15 to 45°C.
• Solubility in water. R dissolves in small quantities: 2.256 g dissolves in 1 liter of water at 0°, 2.534 g at 15°, 2.684 g at 35°; with further heating, the solubility decreases again.

The video talks about building gypsum and how you can improve its properties by giving additional strength:

Types of gypsum

Gypsum has the greatest variety of uses among other binding materials. It allows you to save on other materials. There are many varieties of gypsum.

Building

It is used for the production of gypsum parts, partition boards for plastering works. Work with gypsum mortar must be carried out in a very short time - from 8 to 25 minutes, it depends on the type of gypsum. During this time it must be completely used up. When hardening begins, gypsum already gains about 40% of its final strength.

Since cracks do not form in the gypsum during hardening, when mixing the mortar with lime mortar, which gives it plasticity, you do not need to add various fillers. Due to the short setting time, hardening retarders are added to gypsum. Construction gypsum reduces labor intensity and construction costs.

In deposits by blasting gypsum-containing rock. The ore is then transported to factories in the form of gypsum stones.

High strength

By chemical composition high-strength gypsum is similar to building gypsum. But building gypsum has smaller crystals, while high-strength gypsum has large crystals, so it has less porosity and very high strength.

High-strength gypsum is produced by heat treatment in a sealed apparatus into which gypsum stone is placed.

The scope of application of high-strength gypsum is extensive. Various building mixtures are prepared from it and fireproof partitions are built. It is also made from various shapes for the production of porcelain and earthenware sanitary products. High-strength gypsum is used in traumatology and dentistry.

Polymeric

Orthopedic traumatologists are more familiar with synthetic polymer plaster; plaster bandages are produced on its basis for applying bandages for fractures.

Advantages of polymer plaster casts:

1. three times lighter than conventional plaster;
2. easy to apply;
3. allow the skin to breathe, as they have good permeability;
4. resistant to moisture;
5. allow you to control bone fusion, as they are permeable to x-rays.

Cellacast

Bandages are also made from this plaster; their structure allows the bandage to be stretched in all directions, so very complex bandages can be made from it. Cellacast has all the properties of a polymer bandage.

Sculpted or molded

This is the most highly durable gypsum, it does not contain any impurities, it has high natural whiteness. It is used for making molds for sculptures, plaster figurines, sculpting souvenirs, in the porcelain and earthenware, aviation and automotive industries.

This is the main component of dry putty mixtures. Molding gypsum is obtained from building gypsum, for this it is additionally sifted and ground.

Known for several centuries, it still remains relevant in our time. The most common rosettes are gypsum, they are easy to make with your own hands.

Acrylic

Acrylic plaster is made from water-soluble acrylic resin. After hardening, it looks similar to regular plaster, but is much lighter. Ceiling stucco and other decorative details are made from it.

Acrylic gypsum is frost-resistant and has little moisture absorption, so it can be used to decorate building facades, creating interesting design solutions.

Working with acrylic plaster is very simple. If you add a little to the solution marble chips or aluminum powder or other inert fillers, products made from acrylic plaster will closely resemble marble or metal.

This is what acrylic plaster looks like

Polyurethane

Gypsum stucco can also be made from polyurethane or polystyrene gypsum. It costs much less than ordinary gypsum, and its qualities are almost no different from it.

White

Using white gypsum, seams and cracks are sealed, stucco is made and other types of construction and repair work are carried out. It is compatible with various types of building materials. White gypsum hardening time 10 minutes.

Fine grain

Fine-grained gypsum is also called translucent. It is used to fill seams, joints in slabs, etc.

Liquid

Liquid gypsum is prepared from gypsum powder.

It is prepared using the following technology:

• Pour water in the required quantity.
• Pour in gypsum and mix immediately.
• The density of the solution can be varied. A liquid solution is made to fill the molds

Waterproof (moisture resistant)

Waterproof gypsum is obtained by processing raw materials according to special technology. To improve the properties of gypsum, stillage, a waste product from the production of ethyl alcohol, is added to it.

Refractory

Gypsum is a non-flammable material, non-flammable, but plasterboard sheets, made from it are quite flammable. To give them fire resistance, tongue-and-groove gypsum is used. It is used wherever it is required to increase fire resistance.

Architectural

Architectural gypsum does not contain toxic components, it is very plastic. Its acidity is similar to that of human skin. Classic modeling from architectural plaster is very popular among designers; there is a very high demand for it.

It requires certain knowledge, so you should first carefully study the features of such work, and only then proceed to practice.

Stamps

Plaster marking is carried out after testing standard samples of sticks for bending and compression two hours after they are molded. According to GOST 129-79, twelve grades of gypsum are established, with strength indicators from G2 to G25.

Plaster substitute

An analogue of gypsum is a fine grayish powder white- alabaster. It is also popular in construction. Alabaster is obtained from natural gypsum dihydrate by heat treatment at temperatures from 150 to 180? C. Externally, alabaster and gypsum are no different from each other.

Alabaster is used to plaster walls and ceilings at low indoor humidity. Gypsum panels are produced from it.

What is the difference between plaster and alabaster?

Gypsum and alabaster have the following differences:

1. Alabaster is more limited in application, as it is used only in the construction industry. Gypsum is also used in medicine.
2. Alabaster dries instantly, so it is not suitable without the addition of special substances.
3. Gypsum is safer for environment and human health.
4. Alabaster has greater hardness than gypsum.

Currently there are many various mixtures and materials that are used to create construction products. The choice may be different, depending on the goals and capabilities of the buyer.

The most famous materials in this area are gypsum and alabaster. Frequently asked question: plaster and alabaster - what's the difference? Many professionals associated with construction sector, consider these species to be almost identical. There is some truth in this, since alabaster is considered a subspecies of gypsum. Still, there is a difference between these types of construction products, even a significant one.

Alabaster

It is a fine white powder. Sometimes it happens in gray color. It is actively used in construction. Gypsum stone undergoes a firing procedure after thorough grinding.

Perfect like this the material is suitable for plastering walls or ceilings. This is best done if the humidity is low. This powder is also the basis for building materials. For example, it is used to make gypsum panels.

It is important that the material has extremely low density. This allows you to use it for repair work.

Alabaster can serve as a means of creating noise insulation in a room.

Note: alabaster does not tolerate moisture. Therefore, it is recommended to store it in a dry place.

The construction industry knows the following types:

• Normally hardening;
• Slow hardening;
• Fast hardening.

Gypsum

The concept of gypsum is much broader than alabaster. He is natural material. It has no odor and is absolutely safe for human health. Considered environmentally friendly clean look construction powders. It is obtained from gypsum stone.

This material tolerates moisture and is able to absorb it. In very dry rooms, on the contrary, it highlights it. This is a significant advantage during construction. By fire safety he comes first.

The material has many varieties:

1. Building;
2. High strength;
3. Polymeric;
4. Cellacast;
5. Sculptural;
6. Acrylic;
7. Polyurethane;
8. White;
9. Fine-grained;
10. Liquid;
11. Waterproof;
12. Refractory;
13. Architectural;

Thanks to these various types, this powder can be used in a variety of areas.

Scope of application of materials and their properties

Gypsum is used in several areas:

• construction;
• porcelain making;
• ceramic industry;
• oil industry;
• medicine.

It is also used as a basis for many different building materials. These include mixtures, plaster, various glue, putty. Thanks to its excellent properties, it can be used to seal cracks, remove uneven surfaces, and caulk seams.

Alabaster is primarily a finishing material. Most often it is needed to level any surface.

It hardens almost instantly, so it is actively purchased as a binder. Needed for repairs or to create products.
Other features:

• needed to firmly fix the cables when electrical installation work is carried out;
• for creating beacons and various slopes;
• in order to putty the enclosing structure.

The scope of application of gypsum is much greater than that of alabaster.

Main Differences

These materials have many differences. Not everyone will be able to identify them and see them right away. They differ mostly in their properties.

1. Gypsum is a deeper and broader concept than alabaster. Gypsum is often used in the medical field. Various casts are made from it. It is also actively used in dental prosthetics, and impressions are also made. Careful work is being done, the quality of the material allows. It has been used in medicine for a long time. As soon as its discovery took place.
2. Alabaster has the ability to dry almost instantly. This sometimes becomes his disadvantage. Therefore, professionals have to purchase special additives that are added when mixing the powder.
3. Gypsum is deservedly considered an environmentally friendly product. It is completely safe for human health and the environment in which it is located. This is why it is so popular in the medical field. Alabaster is such a safe and environmentally friendly product. For this reason, its use is limited to construction work.
4. Another significant difference between the materials is that they feel different to the touch. Gypsum has a very soft structure, it is almost smooth. Alabaster is rougher and inferior in softness to gypsum.

All this proves that plaster and alabaster really have some differences.

Breeding technology

It is not that difficult to dilute these powders. The technology is somewhat reminiscent of diluting glue. The ratio of material and amount of liquid (water) is important. This ratio is 1:0.5.

For one kilogram of alabaster, approximately 0.5 liquid is needed. This solution must be mixed thoroughly. As soon as it becomes similar in consistency to sour cream, you can stop kneading. After this, you can start using it. Do not forget that the material dries very quickly.

The technology for diluting gypsum is approximately the same. The amount of powder should be more. Two parts – one part liquid. For 1.5 kilograms of material, an average of one liter of water is required. When kneading, do not allow lumps to remain. The powder should be evenly distributed throughout the water.

To learn about all the differences between alabaster and gypsum, watch the following video: