Putties. How to choose the right material for work

Recommendation points

• Starting and finishing putty
• Subdivision of putty by type of base
• Gypsum putties
• Cement putties
• Polymer acrylic putties
• Polymer latex putties

After reading this article, you will learn how to correctly apply different types of putties: you will learn how the finish differs from the starting one, acrylic from latex, and gypsum from cement. We will also tell you about the features of working with each type of this material..

Starting and finishing putty

All putties are subdivided into starting and finishing. This division is conditional, because the finishing putty can be applied, for example, before wallpapering the walls. Whereas the starting putty can serve as an excellent basis for applying texture to the surface.

From a technical point of view, the finish and start in putties differ in the size of the aggregate fraction. In human terms, the starting putty has grains of quartz sand, which is usually the filler of the putty, much larger than the finishing one. This difference allows you to apply the starting putty in a much thicker layer than the finishing one, without fear that when it dries it will shrink and crack. But starting filler cannot be rubbed to a perfectly smooth surface, even with grouting grinding tools. The surface treated with the starting putty will still remain rough to the touch, while the finish can be sanded to a mirror-like smoothness.

Typically these two fillers are used in tandem. First, one or more layers of starting putty are applied to the surface of the walls or ceiling, and after it dries, the surface is finished. However, this technology is optional. It all depends on the surface and the expected end result.

As mentioned above, starting putty allows you to create a certain texture on the surface. This is used by master finishers – with the help of a special tool and application technique, they create interesting effects. Such textured surfaces can be obtained by working with a starting putty from any material and from almost any manufacturer. It all depends on the skills of the master and the quality of the putty itself. Some brands have separate lines of decorative putties, supplemented with modifiers and plasticizers, and even with additional fractional fillers.

Subdivision of putty by type of base

Start and finish are the separation of absolutely all putties existing in nature. But their main classification is carried out according to the type of base from which they are made. There are gypsum and cement dry putties, ready-made polymer, which, in turn, are subdivided into acrylic and latex.

Each of these types has its own field of application and method of application, has special technical and physical characteristics and even requires different skills from builders-finishers. Some of them can only be used inside buildings, while some are not intended for mineral substrates, but for wood or wood-based panels. In order to understand what is what, it is necessary to consider each type of putty separately..

Gypsum putties

These putties for most people, both professional builders and ordinary consumers, are synonymous with the very concept of “putty”. For a very long time in the post-Soviet period, the Turkish gypsum plaster ASB was widespread, which created this image. I must say that it was a fairly universal and high-quality putty, with which the professional masters managed to work miracles. For example, rub it down to an almost mirror-like surface. Therefore, the requirements for other brands that appeared on our market later were made on the basis of the prevailing opinion about this particular putty. However, very often the expectations turned out to be unjustified..

Gypsum putty is now produced by a large number of domestic and foreign manufacturers in the form of a dry mixture, which is based on gypsum. Best of all, when it is a snow-white plaster, similar to the one used in the notorious ABS. However, domestic producers use gypsum from local deposits, and it usually has a yellowish tint. The exception is putties of the KNAUF concern, which are produced on a fairly white plaster. The filler of the gypsum putty is white quartz sand or marble flour, and the application features depend on the size of the particle fraction of these materials – the smaller the size, the thinner the putty layer can be when applied to the surface. It is the fractional nature of the filler that divides the putties into start and finish, as already mentioned above. Putties filled with marble powder have a much thinner layer of application than with sand filler. It can even be tenths of a millimeter.

But in gypsum putties, the concept of “universal” is very often found. This is due to the astringent base, i.e. gypsum. It is its properties that make it possible, with a thin filler fraction, to apply the putty with a sufficiently thick layer. Other ingredients of any gypsum putty are various modifiers and plasticizers. They are the main know-how of each manufacturer and form the basis of the putty recipe. Their purpose is to impart certain properties and qualities to the composition. For example, extra ductility, preventing curing too fast or too slow, protecting against cracking on the wall or shedding.

Plaster putties have a huge number of positive qualities. They are ideal for residential premises due to the fact that gypsum is an environmentally friendly material, does not emit any harmful substances into the atmosphere during operation, and has the ability to maintain an optimal indoor climate. This ability is due to the fact that gypsum is a very hygroscopic material. It absorbs excess moisture from the atmosphere, which it gives back when the humidity in the room decreases. But precisely because of this property of gypsum, putties, which are based on it, cannot be used for outdoor work..

Cement putties

These fillers have been well known to builders since Soviet times. Of course, then they had a slightly different recipe and were made most often in a handicraft method with the addition of lime mortar. Now such putties are produced in the form of a dry mixture by almost all manufacturers of building materials of this kind..

The basis of the cement putty is, of course, cement. It can be either regular gray cement or white. The brand of cement can also vary depending on the manufacturer and the purpose of the putty mixture. As with other cement mortars, the grade affects the strength of the final surface. Obviously, cement of a higher grade is needed for facade putties. The filler of the cement putty is various types of sand or marble flour. As in gypsum putties, it is the aggregate fraction that affects the thickness of the layer that can be applied. The formulation of cement putties also includes modifying and plasticizing additives, which give the putty additional properties. Many manufacturers also add antifreeze to their mixtures, which makes it possible to work with cement mortar at sub-zero temperatures..

Cement putties are frost-resistant and can be used both inside and outside buildings. They are not as environmentally friendly and useful for the microclimate of the room as gypsum, but they are more durable and resistant to mechanical damage coating. True, such putties also have a significant drawback, which manufacturers are trying to avoid with the help of modifiers – shrinkage. As it dries on the surface, the putty shrinks and cracks. Sometimes this happens a long time after its application. To prevent this from happening, it is necessary to very carefully follow all the technological requirements of the manufacturer, both when preparing the solution and when applying it to the surface. At the same time, it is very important that the base of the surface on which the putty is applied is a material having a higher grade strength or equal to the putty. For this reason, cementitious fillers must not be applied to wood or plastic surfaces, or over plaster substrates. In this case, the putty is guaranteed to shrink and crack..

Polymer acrylic putties

Polymer putties are offered by manufacturers in a ready-made form. This is undoubtedly a big plus, because in this way mistakes are excluded that can be made when diluting and preparing a solution. However, there are some disadvantages in this form. For example, if storage conditions are not observed, such putty may partially or completely lose the technical characteristics and properties declared by the manufacturer..

The binder base in such putties is a polymeric substance, in particular acrylic. Being not natural, but synthetic material, it has a number of significant advantages over gypsum or cement. The main one is the ability of acrylic to interact with other components of the solution, which allows you to get a more uniform and dense structure and avoid shrinkage or cracking due to non-compliance with the application technology.

It is much easier to work with such a putty than with dry analogs. Indeed, regardless of the addition of plasticizers, the acrylic mixture is very plastic in itself. In addition, acrylic putties have a fairly versatile field of application. They can be used to putty on almost any surface, be it wood, drywall or concrete. Acrylic is a frost-resistant material, therefore, putties based on it can be used both indoors and on the facades of buildings.

The thinner for acrylic-based putties is water, therefore, if the material dries out too much, it is permissible to slightly dilute it with cold water. The filler for polymer finishing materials is usually marble flour or fine marble sand. Putties, like gypsum, are subdivided into starting and finishing, but usually in ready-made solutions such a division does not depend on the aggregate fraction, but on modifiers and their quantity. A significant disadvantage of acrylic putties can be attributed to their rather high cost, especially in comparison with cement and gypsum analogues. However, this disadvantage is slightly offset by the economical consumption and ease of application of this type of material..

Polymer latex putties

Latex is another type of polymer that acts as an astringent base in ready-made polymer putties. It differs from acrylic in its greater resistance to various types of loads that the putty can expect during operation. After all, latex is, in fact, rubber, so it gives the putty a special elasticity. The putty can be either completely based on latex or on its combination with acrylic – acrylate. This practically does not affect the properties of the putty. You can use latex putty on absolutely any, even metal, surfaces, which is absolutely unacceptable for other types of putties.

Its disadvantages include the high cost and the fact that the surface, which has been treated with such a composition, practically does not “breathe”. Also, latex materials have low vapor permeability, so it is not recommended to finish walls or ceilings with this type of putty in residential premises. Otherwise, it is an excellent versatile finishing material that is very easy to work with. It absolutely does not shrink and is suitable for use over a wide temperature range. In addition, manufacturers add various antiseptic substances to polymer putties that prevent the formation of mold, mildew, the appearance of corrosion or efflorescence on the finished surfaces..

This overview of putties gives a fairly general idea of ​​this diverse finishing material. For a broader understanding of putties, you need to familiarize yourself with the manufacturers and the assortment that they offer to consumers..