In interior finishing work, various filler mixtures are used to level surfaces. But what if the surface to be treated is outside? In this case, it is necessary to use a special putty for facade work, which has a greater level of wear resistance and lower sensitivity to temperature extremes.
Types of putty depending on the purpose of application
Putty is a dense mass consisting of binding elements, which when solidified forms a solid surface. Putty is used both in internal and external decoration. The main purpose of the facade putty is to align the elements with flaws, fill small voids to form a smooth surface.
It can be sold in two forms:
If a large amount of work is expected, then preference is given to a dry mixture, which is diluted with water according to the instructions to obtain a creamy mass. Facade putty for exterior work in the form of paste is intended for fine jewelry work, it is used in the restoration or filling of small gaps in the walls, as well as in the manufacture of decorative elements. The disadvantages of ready putty mixtures are their limited shelf life and quick solidification.
Depending on the place of work and material, different types of putty are used.
- on a cement basis;
- on a gypsum basis;
- acrylic;
- latex;
- oil-glue.
In facade work, putty is used on a cement, acrylic or latex basis. This is due to the high level of wear resistance of these materials and resistance to temperature changes, as well as due to resistance to moisture.
Features of facade putties
The main functions of putties for external work is the formation of a protective layer and decorative design. Materials for the exterior decoration of buildings should have a certain list of properties. Immunity to seasonal changes in temperature and precipitation makes the plastered surface strong and durable. These are the most important characteristics of facade putty. A significant role is played by a high level of adhesion, that is, the ability to adhere to any material. Compatibility with any paints and varnishes is a prerequisite when choosing a putty.
Due to the large surface area to be treated, preference is given to dry mixes, which are mixed using water to obtain a finished mass. According to reviews, the facade putty, which has gained the most popularity, is made on the basis of cement.
Cement-based putties
A great option for facade surface treatment. It is supplied in the form of a dry mixture consisting of cement, sand and some bonding elements. The cement, which is part of the putty, provides the future surface with a high level of strength and moisture resistance. One of the most popular in the construction environment is the facade Knauf putty. This company is engaged in the production of base and top coatings.
Preparing putty from the mixture is not difficult, the instructions are on the package. You can apply it yourself. There are two types of cement putty: base and finish. The basic facade putty can be applied with a thick layer of up to 1.5 cm and serves as a filler for large cracks and irregularities. In its composition, it is more granular, so the surface is rough. Finishing putty has a finely divided composition; when dried, it forms a smooth and even surface. The use of Knauf cement putty for facade work should be carried out at a temperature of at least +5 degrees and a humidity of 80%. To reduce the drying time, it is recommended to use putty at a temperature of +20 degrees. The finished mixture can not be mixed with paints, glue or other substances, it can lose its properties, which means that the quality of work will be low.
Both amateurs and professionals note in their comments that cement-based putty is one of the most popular materials in facade decoration, since the price is an order of magnitude lower than analogues and the quality of the coating is at a high level.
Polymer putties
Polymer putties in the field of construction appeared relatively recently. It is very convenient to use, and can be stored in diluted form for up to 12 hours. Long hardening makes it very comfortable to use. The advantages of polymer blends include:
- durability;
- strength;
- no shrinkage;
- plastic;
- lack of pungent odor.
All polymer putties can be divided into two groups: acrylic and latex.
Acrylic Putties
The surface of acrylic putty has a high level of strength and retains its properties at large temperature and humidity extremes. This material is very ductile and not subject to peeling. Apply a layer of not more than 3 mm and only on a primed surface.
A significant disadvantage of acrylic putty is its high cost, as well as incompatibility with wooden and metal surfaces. In the presence of deep irregularities, it is necessary to apply acrylic putty in several layers.
Latex Putty
It is delivered in the form of paste, ready for drawing. Depending on the purpose, two types are distinguished: leveling and finishing. Suitable for application on any surface, including wood and metal. The pre-treated surface must be primed.
Dilution of latex putty with water is allowed, but not more than 1% by weight. You can work only at temperatures above +5 degrees. The shrinkage of the material is minimal, this eliminates the formation of cavities in the form of bubbles. The mixture is resistant to temperature changes; during the seasons of the year, the coating remains as strong and does not deform.
A variety of colors will save on painting, and the finely dispersed composition of the latex putty will give the wall a smooth look. Such a surface does not need additional processing.
Mixture preparation
Each manufacturer gives detailed instructions for preparing putty from a dry mixture, the proportions are indicated on the package itself. To prepare it with your own hands you will need water, its amount must strictly comply with the instructions. If there will be more or less water, such a mixture will give a poor-quality coating. As containers, you can use a construction bucket or any other container of suitable volume.
Weight mixing is done using a special mixer nozzle on the drill. Make sure that the mass is homogeneous, with no visible fractions of dry material. After you knead the mass, you must leave it for 10-15 minutes and mix thoroughly again. Do not cook a lot of solution at once, it can dry out and will no longer be homogeneous. Ready facade putty should be used within 20 minutes. The speed of rotation of the drill should not be more than 800 revolutions per second, otherwise you can get a porous solution.
Homemade Putty Recipe
If you decide to make a cement facade putty with your own hands, then you will need:
Cement and sand are mixed in a ratio of 1: 4. The sand should be clean, sifted, without lumps of clay and stones. Cement needs to be taken with the M400 brand. First mix the dry mixture, then add water. The mixture should not be too liquid or thick. Suitable consistency of thick sour cream. To obtain a light putty, you need to use white cement. Such a mixture is suitable for applying the main layer, after drying it must be covered with a finishing layer of finely divided putty. Home-made putty is often used by experienced plasterers.
Putty Tools
Tool selection depends on the amount of work. The most important tool in carrying out these works is a spatula. It is better to immediately purchase a set of different sizes. If it is necessary to putty a large area of the wall, then the putty knife should be large, small and hard-to-reach places are putty small. Rubber and silicone spatulas are very convenient to use, they are easier to apply the mixture, and level the surface.
In facade works, it is worth giving preference to a better spatula, since the material is used rough and heavy. Carbon steel spatulas have proven themselves best, they are durable and will not bend even when working with heavy masses. For processing corners, it is more convenient to use a corner spatula. It will form a clear and even angle of 90 degrees.
To mix the mixture, you will need several plastic construction buckets. After the first stirring, when the mixture has stood and needs to be mixed again, the solution is poured into a clean container. This must be done so that the putty parts dried up at the edges do not get into the mass with repeated stirring.
Application technology
To obtain a neat and smooth surface and to fill in all the bumps, it is necessary to observe the technology for performing puttying work. If you skip or poorly complete the preparation of the working area, then the finish will not last long. Over time, delaminations will appear, the coating will begin to crumble. To prevent this from happening, it is necessary to perform all the steps without fail.
Putty leveling technology for facade work includes the following phases:
- Before applying the mixture, it is necessary to clean the surface, if necessary, treat the wall with a special antifungal solution.
- Apply a primer in 2 layers. This is necessary to create a protective moisture-resistant layer; puttying material will be better fixed on it.
- Apply the first coat of putty. To do this, you need two spatulas. Smaller material is applied to the wall, and large is needed to take a serving of putty.
- After complete drying, a second coat is applied.
- In conclusion, we cover with a finishing thin layer to form a perfectly smooth surface.
- We process the coating with a fine-grained sandpaper on the holder to remove the remaining bumps.
If it is planned to paint the surface, then at the final stage we use an abrasive skin of 120-150.
If you want the surface to have a texture, then you need to apply the technology of textured putty on the walls.
A regular long-nap roller can create a nice, rough surface. If you want to depict the texture as stripes, then you need to use a comb for tile glue. The direction of the stripes may be the same or chaotic. A sea sponge is also used to create the texture; it can be bought at a hardware store.
Unconventional use of putty mixture
The ability of putty for facade work during drying to create a solid and durable structure allows its use in the manufacture of various interior elements. From putty, you can make a relief panel or picture.
Compositions can be made using patterns. The house in the antique style is harmoniously complemented by frescoes made by hand, and ordinary flower pots after decoration with putty will become a work of art. In this case, it is necessary to use a facade putty, it will give a better product that is immune to the effects of water.
Cement-gypsum-based putties can be used to make figurines, decorative tiles and elements for facing vases. Make sure that the thickness of one layer does not exceed 3 cm, otherwise cracks may form on the finished product when it dries. Apply facade putty in several thin layers.
Conclusion
The processing of facade surfaces must be approached wisely. After all, this is not only the creation of a beautiful design of the house, but also the formation of a protective layer from external influences. If you decide to putty the facade of the house yourself, then do not neglect the important stages of the technology for performing this process. Indeed, the omission of one of them can lead to poor-quality results, as well as the loss of money and time.