Painting works take up a very large part of the budget in the finishing complex, and putty mixes are almost always used on objects. Putty(putty) is a paste-forming building material that is used for leveling, preparing the base, fixing lighthouses and in other works. Due to its consistency and technical properties, it provides a long-lasting coating that can be further processed.
What is putty?
Putty is most often used in the form of powder material, which is then diluted with water to produce a plastic solution. Then this material is applied to the prepared surface after dedusting or applying a primer. It is used for the following tasks::
- Surface preparation before painting;
- Manufacturing based on decorative coatings;
- Leveling large surface differences;
- Providing a solid foundation for further finishing;
- Finishing of drywall joints;
- Fixing of electrical boxes, sub-sockets, profiles, beacons, various structures;
- Finishing of facades.
In general, we can talk about the universal use of this material, but there are some types of special-purpose materials.
Main components of putty solutions:
- Gypsum;
- Cement;
- Chalk;
- Lucky ones;
- Synthetic Resins;
- Latex;
- PVA.
Each of these components gives special properties to the solution, which provides the desired characteristics of the putty after it dries.
Types of putty
Varieties of putty are determined by the method of application:
- Leveling-starting) – has a large fraction of filler, allows you to work with a large layer thickness, is used for forming slopes, leveling walls, ceilings, openings. It has high adhesion, which is very useful for further finishing with other materials. The average thickness of the layer reaches from a few millimeters, up to 2-3 cm.
- Finishing putty-more plastic, stronger, used for perfect alignment of the surface before pasting wallpaper, applying decorative plaster, painting. The average thickness of the applied layer can be 0.2-1 mm, which is enough to fill the pores after using the starting putty. Due to the fact that the composition uses a filler with a smaller fraction, it easily fills in pores and irregularities after using the “start”, it levels out scratches and minor defects in putty work well. In some cases, it is necessary to apply several layers of finishing putty sequentially to achieve the best effect of finishing walls or ceilings. It is convenient to use it on drywall, but for working with cement-sand plaster, finishing putty is rarely used due to the high consumption. Please note that the strength of the dried putty significantly exceeds the starting one, so for surfaces with intensive use, it is advisable to use the finishing putty. The disadvantages include the high price, difficulty in grinding, and high setting speed. The finished surface has the appearance of polished, sometimes after the completion of painting work, no further processing is required. In some cases, paint mixes are also added to the finishing putty to create the effect of decorative plaster.
- Universal putties-medium fraction size and medium strength ensure low production costs and versatility of the material. Such solutions are useful to use with minor changes in height, if the budget is limited, to strengthen the base. Less often, putty of this category is used when laying gypsum blocks during surface decoration. Its strength is sufficient for use in residential and commercial buildings, and the overall budget savings can be 20-30% compared to multi-layer finishing “start” and “finish”.
- Special purpose putties are building materials that have pronounced specific characteristics (elasticity, heat and sound insulation, vapor permeability, high strength). They can be used at the junctions of various materials to compensate for linear extensions, for surface reinforcement, overlap of vibrating nodes, and other special tasks. Prices for such putties vary greatly depending on their composition and properties.
From the entire list of putties listed above, two types are used everywhere in housing construction: gypsum and cement putties.
- Gypsum-does not shrink, is ideal for use in residential areas, participates in the regulation of the indoor climate, and has a low cost. Disadvantages-low strength, high consumption of putty, poor resistance to moisture, can be a breeding ground for fungi, mold and other microorganisms.
- Cement-has increased strength, can withstand prolonged contact with water. Disadvantages-the cost is higher than that of gypsum putties, the material shrinks, which can cause defects in the form of microcracks on the surface after drying.
Please note that the key property of different types of putty is the filler used, or rather its dispersion. Coarse solutions have a grain size of 80 to 200 microns, medium – dispersed solutions have a grain size of 20-80 microns, “thin” putty has components with a grain size of up to 20 microns.
Technical characteristics of putty
Different types of putty are used for different tasks due to the difference in their properties.
The average values for dry building mixes are as follows:
- Water consumption at the rate of 25 kg-3.5-4 liters;
- Compressive strength-4-8 MPa;
- Bending strength-1-3 MPa;
- Recommended layer thickness-1-20 mm;
- Consumption per 1 mm layer-0.7-0.9 kg per m2;
- Pot life of the solution-10-120 minutes;
- Adhesion-0.3-1.0 MPa;
- The density of the ready-to-use solution is 1900 kg / m3;
- PH-12-13 units.
Many manufacturers, in order to increase sales with additives, try to give certain properties and characteristics of their products. For example, it can be frost resistance, increased ductility, increased strength, and so on.
Scope of application of putty
- Sealing joints in drywall structures;
- Fixing drywall fragments and lighthouses;
- Fixing the reinforcing mesh;
- Continuous plastering of walls made of brick, concrete, gas block, expanded clay and other structural materials;
- For filling joints in masonry materials;
- For sealing strobes when laying wiring, other communications.
The versatility of use is due to the good performance properties of putties after they dry.
What kind of putty should I buy?
To choose a putty and not overpay at the same time, it is important to start from the technical specifications. For example, gypsum putty is not suitable for use in a wet environment, if you use a finishing solution, you can significantly exceed the cost of painting. The rules for using putty are regulated by GOST, but it is easier to consult with the builders who will apply the solution before buying the material.
Recommendations for choosing a putty:
- Give preference to well-known brands;
- Keep track of the shelf life and storage conditions of the material;
- Carefully study the composition and purpose of the materials. For residential areas, it is not allowed to use putties with toxic or harmful components;
- Putties with sand are perfect for starting processing and working with large layers, but they are poorly suited for finishing, since the thickness of the applied layer may be less than the size of the grains of sand that make up the solution;
- If there is high humidity or poor ventilation in the rooms, give preference to putties with a hydrophobizer;
- For ceilings and walls, different putty is usually used, which is due to the different thickness of the applied layer;
- Low material price-low cost of components. This may mean that the solution is not uniform, that there is a large filler fraction, or that the quality of the viscous substances is poor.