Good plaster serves for decades. Nowadays, cement finishing coatings have been replaced by gypsum mixtures. But not all plasterers abandon the usual materials. Let's look at the strengths and weak sides gypsum and cement mixtures and figure out which plaster is better.
Features of cement-based plaster mixture
The word “plaster” comes from the Italian term stuccatura, which denoted finishing materials familiar to the Romans (lime, alabaster, gypsum). Under modern plaster refers to a hardened building mixture intended for leveling walls. It is impossible to say clearly which solution is better and which is worse. Compound optimal coverage depends on many factors.
Plaster mortars have been used for thousands of years to decorate houses, apartments, and building facades. The sought-after finishing material has evolved along with humanity. In recent decades, builders have used predominantly cement coatings when constructing and renovating houses.
The mixture consists of cement (main component), sand (filler), plasticizers. Limestone, gypsum or combinations thereof are used as the latter. Solutions are distinguished by the proportions of the components and depending on the surfaces being finished. Coatings on cement based cover the walls outside and inside buildings. Moreover, in the latter case, the premises may be unheated and with high humidity.
TO strengths cement finishing mortars include:
- versatility;
- plasticity lasts for several hours - you can immediately prepare a large volume, consuming it as needed;
- strength of the finishing layer;
- affordable price.
However cement plaster far from ideal. Masters note the following disadvantages:
- the mixture does not fit well on a concrete base:
- the layer dries for about 14 days, which reduces the pace of finishing work;
- increased humidity when working with the mixture - to crystallize cement particles, the surface to be finished must be sprayed with water;
- the main component cement gives the finished surface an unsightly gray color;
- on final stage finishing putty is required;
- When working, a suspension of sand and cement rises into the air and enters the respiratory tract.
The main problem when working with cement coatings is a cracked finishing layer. In addition, as the composition dries, it will shrink, which will lead to the appearance of unevenness. By the way, for this reason, additional equipment (heating elements, hair dryers, heat guns) is not used for drying rooms.
Thus, cement finishing solution suitable for walls in technical rooms, facade works, in apartments with rough and.
Advantages and disadvantages of gypsum coatings
Despite all the advantages cement mortar, for interior decoration, gypsum plaster confidently competes with it. As the name suggests, the main component of the mixture is gypsum powder, made from a natural mineral. During the production process, after long-term heat treatment, this powder is crushed. As a result, the finer the fraction (grain size), the better the quality of the processed surface.
In addition to gypsum, the solution contains natural or synthetic fillers, polymer additives. For leveling walls, the shape and size of the grains are of no small importance. In addition, fillers reduce mixture costs and increase the strength of the finishing layer. And polymer ingredients increase the adhesion of the solution and make it more elastic.
Based on the technical characteristics of the finishing coating, its advantages can be highlighted:
- High adhesion – the solution adheres to any base;
- Leveling ability - a surface finished with a gypsum coating is immediately ready for painting, whitewashing, or wallpapering;
- The consumption of this mixture is lower than that of cement. True, for this you need to comply with the regulations and work technology;
- Solid thickness of the finishing layer - sometimes it reaches 6 cm;
- The mixture is easy to work with - it fits well on the surface, is leveled, smoothed;
- The surface treated with such plaster acquires additional sound and heat insulating qualities.
Despite all my positive traits, gypsum coating is not used everywhere. There are reasons for this:
- Price. Gypsum mixture costs 1.5–2 times more than cement;
- Strength. The surface plastered with gypsum coating does not withstand mechanical damage;
- The solution sets quickly, so to avoid overspending it will have to be prepared in small batches;
- Need for use additional materials. For example, when treating a concrete surface it is necessary to use primer solutions, and plastering metal surfaces without a waterproofing layer is unacceptable. Moreover, to this decorative coating It is not recommended to lay tiles. Upon contact adhesive composition with the finishing material, ettringite is formed - a mineral that destroys gypsum.
The main disadvantage of this mixture is that it is undesirable to use for treating surfaces outside the house.
Among gypsum finishing coatings, there are three types. The first is a fine-grained solution; it contains carefully ground sand. It is recommended to apply this material in layers 0.5–0.8 cm thick. For leveling, apply a second layer. The main area of application is finishing ceilings.
Medium-grained gypsum building mixture is the most popular and, as a result, widespread. This is the main competitor of cement-based mortars. Allowable thickness 5 cm.
To hide significant surface defects, coarse-grained gypsum plaster is used. As a rule, it is used to repair broken slopes and renew facades. By the way, in the latter case, the selected mixture must be checked for resistance to water. Sometimes, despite manufacturers' statements, it is better to play it safe and apply protective layer.
Working with gypsum and cement plaster - comparative analysis
The main factor that determines which plaster is better and which is worse is the characteristics declared by the manufacturer. But along with them, you need to take into account secondary factors - ease of use, the need to use additional materials.
At first glance, the advantages of gypsum coatings are obvious - they are elastic, stick to any surface, and are easy to grip. And the faster the layer hardens, the faster the work moves. But if you lack skill, the prepared batch of plaster will dry out. Her reuse impossible. In other words, the price of a mistake is additional costs, and the cost of gypsum plaster is not affordable.
Cement plaster mortar dries for at least two hours, allowing you to cover it in one go large areas. However, the adhesion of such a composition is lower and in some cases (ceiling, corners) the surface will have to be reinforced with plaster mesh. On the one hand, this entails additional labor costs, on the other, the strength of such plaster is many times higher.
As you can see, the answer to the question of which plaster to choose will be ambiguous. For outdoor use the best option will become cement plaster. And here gypsum mortar – great option for work inside the apartment (except for the kitchen, bathroom, etc.). In rooms with high humidity, you will have to coat the finished surface with varnish.
Alabaster is a building material widely used for leveling and filling walls. It is a type of gypsum, so these concepts are often confused. Let’s sort these materials “on the shelves.”
Are plaster and alabaster the same thing?
Gypsum is calcium sulfate hydrate, natural material, widely used in many sectors of life and industry. Made from plaster building mixtures, it is used by sculptors, gypsum is also known in medicine.
Gypsum is a wide group of materials with different admixtures, compositions and applications.
Alabaster - what is it? This is a type of gypsum mineral used in construction and has a narrow specific application. That is, there is, by and large, no error in substituting concepts. It’s just that gypsum is a broad concept, and alabaster is a narrow one.
Characteristics of alabaster
When choosing building and finishing materials, professionals primarily pay attention to technical indicators dry mixtures and working solutions.
Properties building gypsum:
- Composition - calcium compound hemihydrate;
- Compressive strength (average) - 4.0 MPa;
- Bending strength - 2.0 MPa;
- Brand of binder (gypsum) - G4 and higher;
- Color - white or light gray (almost white);
- Water consumption per 1 kg of dry mixture is 0.65-0.70 liters;
- Setting time is 6-30 minutes from start to finish.
General performance properties of building gypsum (alabaster):
- The solution fits well on a prepared surface of any material;
- High adhesion;
- The surface can be given a perfectly flat state in short time(up to 5 minutes);
- When dried, alabaster does not crack, does not dry out and does not change its volume at all;
- The hardened layer of mortar absorbs noise, so it can be used as an additional means of protecting rooms from sounds;
- Alabaster is warm to the touch and prevents heat loss.
Application of alabaster
We have already found out that alabaster is a building material used in the repair and construction of residential and public buildings, namely:
- As dry mixtures for preparing plaster and putty solutions;
- For repairing cracks and potholes;
- Alabaster is part of gypsum plaster partitions for interiors and apartments.
Construction gypsum has found application in finishing and repair work due to its properties of rapid setting and ideal surface leveling, as well as good adhesion. An alabaster layer prepares the base for wallpaper, tiles, decorative plaster in bathrooms, toilets and living rooms, bedrooms.
The surface of the hardened building plaster should not be exposed to moisture. When arranging walls in bathrooms, alabaster should be insulated with tiled cladding.
How to grow alabaster
The overall finishing result and ease of use depend on the correct preparation of the working solution. There are several subtleties in this matter.
Proportions
SNiP regulates the amount of water for mixing alabaster plaster solution in the amount of 1 kg of dry mixture per 0.65 liter of liquid. This proportion is appropriate for preparing putty and plaster mortar.
For mixing installation and repair mortar, the appropriate proportions are 1 kg of dry alabaster per 0.5 liter of water.
To make a liquid putty solution, you need to take water and the mixture in a 1:1 ratio.
To extend the setting time of the solution, you can add 2% of the volume to it wood glue animal origin, for example bone.
Selection of cookware
Before diluting alabaster, you need to choose the right dishes. A metal container is definitely not suitable for mixing - the solution will stick to it as it dries, and it is not easy to clean such deposits.
A plastic or, better yet, a rubber container is suitable for preparing the working mixture. In order not to stain the vessel, you should lay a thick layer in it. plastic bag, hooking it onto the edges of a bucket or basin.
Professionals note: alabaster does not stick to rubber. If you need to prepare a single portion of the material, use a cut rubber ball.
Correct mixing
How to dilute building plaster:
- Pour the required measured amount of water into the container;
- Gradually introducing the dry mixture, stir the solution with a spatula; for large volumes, use a construction mixer or drill with an attachment;
- Add the dry mixture until you obtain a suitable paste consistency.
For plaster, the mixture should have the consistency of sour cream - equally plastic and moderately soft.
Working with solution
With diluted alabaster you can plaster a wall, fill a gap or pothole, or fill a groove.
How to cover cracks with alabaster:
- The groove/crack/pothole should be cleared of flaking material with a stiff brush, and dust should be swept out with soft bristles.
- Handle work surface deep penetration primer. It will improve the adhesion of materials and protect the repair area from further delamination.
- Mix the working solution. For repairs we use a mixture to water ratio of 1:0.5.
- Use a spatula to apply the solution in the direction of the crack, remove excess mixture with a transverse movement and level the surface.
Working with alabaster is no different from using other plaster mixtures. To cover the surface of the structure, dilute the solution 1:1 and apply a thin layer using a spatula.
How long does it take for alabaster to dry?
As stated in technical specifications, the drying time of alabaster from the moment of initial setting to hardening is 5-30 minutes. That is, the solution needs to be worked out in 5 minutes. If the gypsum begins to harden in the bucket, it is useless to dilute it; such material must be thrown away.
Experienced craftsmen mix up to 5 kg of mixture at a time; for local repairs, you should prepare a little alabaster.
As already mentioned, glue of animal origin will help to extend the setting time of the solution. For 1 kg of dry mixture, it is enough to add a tablespoon of bone glue. For quality finished material it will have no influence.
It is difficult to imagine a renovation without using this material. Alabaster, whose use is very wide, is one of the most common materials used in repair, construction, decorative design interior IN trading network it is sold as a white powder, diluted with water before use. From others similar materials it is distinguished by rapid hardening.
Concept, types, properties
It is called building alabaster or gypsum, consisting of a dry mixture of components. Gypsum is considered the main substance among them. The elasticity of alabaster is provided by polymer components. This material is classified as non-flammable, environmentally friendly natural materials. It has excellent soundproofing properties and water resistance.
Advantages and disadvantages
Before you start working with a mixture prepared from alabaster powder, you should study the characteristics of the material used. The powder is inexpensive and is in deserved demand among buyers for its excellent technological performance. In general, construction alabaster has the following properties:
- dries quickly upon contact with water (sets in 5 minutes, completely hardens in 30 minutes), which makes the material indispensable when you need quick and high quality finish surfaces;
- preventing the appearance of cracks;
- an even film is formed on the treated surface;
- good fire-resistant properties (difficult to ignite);
- high sound insulation.
This finishing material has light weight and does not shrink during the hardening process. If the question arises as to whether alabaster is harmful to human health, then we can absolutely say that it is safe. The powder is predominantly white in color, but it also occurs in other colors: light gray, yellow, and sometimes it has greenish and pink shades.
What temperature can alabaster withstand? It can withstand exposure to significant temperatures. Resists heat up to 700° without destruction. The destructive consequences of interaction with open fire will be visible after 6 hours.
Negative characteristics of the material include its insufficient strength and inability to withstand heavy loads. Due to the fact that alabaster can absorb water when hardening, it should not be used in particularly damp rooms. The frozen alabaster mixture does not like it when the air around is dry and hot, then the material will simply crumble due to loss of moisture reserves and a decrease in viscosity. Such disadvantages are eliminated by introducing various additives into the alabaster solution.
Features of the material
When working, you must remember about the characteristics inherent in this substance. In addition to the rapid hardening characteristic of it, it is capable of increasing in volume. Distinctive feature This material also lies in the fact that it does not stick to the surface of rubber products. It is even recommended to prepare a solution from it in a regular rubber ball. The material is stored in a dry place with humidity not exceeding 60%.
Currently Based on the rate of hardening, the material is divided into the following types:
- with rapid hardening;
- with normal hardening speed;
- with slow hardening.
In the first case, the mixture used will begin to set a few minutes after its preparation, and after a quarter of an hour it will completely harden. The solution of the second type will begin to harden after preparation after 7 minutes, and will finally harden in 35 minutes. For the latter type of mixture, hardening begins after 20 minutes. from the moment of preparation, and the solution will finally harden after 40 minutes.
The difference between alabaster and plaster
Often people who do not own necessary information, Both alabaster and gypsum are considered the same material. In fact, alabaster is obtained from gypsum after its thorough processing. First, the gypsum is crushed, converted into powder, then heated until a temperature of 180° is reached. As a result of all operations, alabaster is obtained.
A little about plaster
It is a natural material, environmentally friendly, odorless. Unlike alabaster, it has a wider range of uses. Its frequent use in construction is due to its good viscosity, fast, durable drying, and significant resistance to fire.
WITH positive side gypsum is characterized by the fact that it is able to absorb excess moisture in room; and if there is a lack of moisture, it can give it back. Such unique property others don't building materials, which allows gypsum to become widespread in internal works for finishing of residential (industrial) premises.
Differences
Visually, the difference between these two substances may not be detectable. You need to look for her soon in the properties of each material, and not in a simple inspection of the result of their application. Gypsum, unlike alabaster, has greater versatility in use. Gypsum is used in various fields of human activity. Among them is medicine, where it is used in the making of casts.
Such plaster casts in dental clinics they are needed in the manufacture of dentures. Casts have high quality. This promotes precise work that results in a person being comfortable with artificial teeth. Making dental impressions is just one of the uses of gypsum in the medical field, where it has been used almost since the discovery of the material.
For example, it is well known that when an arm (leg) is broken apply a special bandage (plaster). In addition to medicine, gypsum is used in architecture and art. Gypsum was used to create various bas-reliefs, for internal and exterior decoration classical stucco buildings. In sculptures applied arts Gypsum-based decorations are also popular.
The alabaster mixture dries and hardens faster than plaster. This property prevents the use of alabaster in the field of medicine and art. Often even with construction work components are added to the alabaster solution to prevent it from hardening. There are no such problems when working with gypsum. Gypsum, unlike alabaster, is softer.
Application of alabaster
As finishing material it is used in construction:
- Production that produces dry plaster, plasterboard panels, stucco molding, and other products cannot do without it.
- It is used to seal cracks, holes, chips, and seams on the walls and ceilings of rooms.
- The use of alabaster helps to fix electrical cables inside special grooves.
- It is used in the production of slopes, beacons, puttying walls and other fences.
Often, due to rapid hardening, alabaster is added to mortar cement in order to slow down the hardening process of the solution. At the final stage, the surface treated with alabaster mortar is often polished, ground or scraped. It should be remembered that no contact between the alabaster product and water should be allowed, otherwise any polish will become dull.
Selecting containers for preparing the mixture
Since the mixture obtained from alabaster powder tends to rapid hardening, diluting this material with water somewhat different from other similar solutions. If you prepare the mixture in a bucket or bowl, then when the alabaster hardens in it, the container will have to be constantly cleaned of it, which is problematic. In this case, experienced builders try to dilute a small amount of alabaster using rubber containers.
The remains of alabaster can be easily removed from there by squeezing an elastic thing. This convenient device it can be made from a simple chamber, half a rubber ball. When breeding large quantities mixtures at one time, inner surface containers are covered for their safety plastic film, the edges of which are securely fastened.
Preparation of working solution
Anyone working with alabaster should know how to breed it. The process of preparing a working solution of alabaster is reminiscent of the procedure for diluting dry glue before gluing wallpaper. To do this, take the components at the rate of: for 1 kg of alabaster - 0.5 liters of water. The selected container is filled with water, into which dry alabaster is carefully poured. The components are mixed, preventing the formation of lumps, until the consistency of sour cream is achieved. After about 2 min. the mixture is ready.
Freshly prepared alabaster solution is used immediately after preparation. If it dries out, it will be unusable. In order to use the solution longer, you need to know what to add to the alabaster to make it harden more slowly. Adding glue (carpentry, wallpaper) to the solution in an amount of 2% of the total weight of the mixture and a lime solution will help delay the drying process of the material.
To ensure that the result of the work meets the requirements, you need to know how to dilute construction alabaster in relation to a certain type of work. Water resistance of alabaster product improved by applying paint or a special moisture-proof layer to its surface. To apply the prepared alabaster mixture, use a spatula or trowel. Upon completion of work, the tools used are thoroughly washed.
Alabaster solution for various types of work, done correctly
To obtain good result work, certain proportions should be observed when preparing the mixture. Otherwise, the mixture will either harden quickly or not dry at all. To avoid such situations, you must adhere to a proven recipe.
First, 0.5 liters of water is poured into a rubber container, and 1 kg of alabaster from a bag is gradually poured into it. The bag with the material is held with one hand, and the mixture is mixed with the other. When mixing, no powder should remain on the walls of the container. The result will be a homogeneous mass without lumps. It should not be stirred for too long to avoid loss of strength.
After 5 min. After cooking, the mass will thicken. It will take 20 to 30 minutes for the solution to completely harden. Taking this fact into account, you should take the amount of alabaster for kneading that can be used in 5, maximum 7 minutes. work performed. The prepared solution is used for covering formed cracks, fixing wires, and other minor work.
Applied to plaster used for walls requires a slightly different preparation of the mixture. To begin with, the type of work to be done is determined. It is better to level the outer walls of buildings using cement mortar. Internal walls covered with a mixture of lime. If you use alabaster for plaster, using it with lime is suitable for eliminating all kinds of errors on the walls: cracks, cracks.
A dry lime mixture is first prepared, to which water and alabaster substance are then added. Instead of containers, you can use the remainder of a rubber tire (another container) more than 10 cm in height. First, a certain amount of sand (1 part) is poured into it, then lime (5 parts). Next, use a spatula (construction mixer) to mix these substances until smooth.
Then add water, stirring the mixture until it reaches the consistency of rich sour cream. After this, they begin to make an alabaster “dough”, 1 part of which should account for 4 parts lime mixture. Next, the alabaster “dough” is poured into a container with lime. All components are mixed briefly but thoroughly. Having prepared the substance, they proceed directly to the construction work itself.
The first step is to “spray” the surface when a small amount of mixture is taken with a construction shovel, sudden movement hands rushes to the surface of the wall. Do this carefully so that the material does not splash the entire wall.
The next step is to apply primer using a wide spatula. The soil layer is leveled. A thin layer of plaster is placed on top. They cover the soil until it dries, using a roller (brush). When the plaster itself has dried, it is processed counterclockwise with a construction plastic trowel, using circular movements of the hand.
Having an idea of what alabaster is, its use in performing certain construction and repair work can be obtained in high results from its use. You only need to know approximately how much alabaster powder is needed to complete a given amount of work, in addition, you should follow the recommended proportions when diluting it.
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 has White color 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 is 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