Without this material, no finishing work is done today. The primer is a liquid composition designed to improve the adhesion of various materials. This clutch is called adhesive.
Adhesion is the ability of various building materials to bond firmly to each other. If we talk about the primer of the floor, this composition improves the adhesion of the screed to the base, strengthens the laying of tiles, etc. The primer also prevents the absorption of moisture into the base, as a result, the screed dries more evenly, thereby reducing the risk of cracking.
And this is not all the purpose of the primer. It strengthens the surface, enhances vapor permeability. Another important purpose of this material is to rid the surface of building dust. Primer floors are required for different surfaces. Which composition is suitable for a particular surface, we will tell in this article.
Is a primer necessary?
Not all people far from construction work understand why a primer is needed for the floor, for example, before laying tiles, creating a bulk coating, etc. It would seem that the finish layer completely hides all the shortcomings of the base, and in the end the whole load falls on it.
This is true, but only in part. The thing is that the quality of the finish coating depends on the strength of its adhesion, the quality of adhesion to the base. When it is not enough, screed, self-leveling floor, tile adhesive and other coatings will lag over time and, most likely, become deformed. To prevent this from happening, a floor primer is required. Let us consider in more detail what other functions this material performs.
Strengthens the structure
For example, if the base of the floor is loose, porous, layered, before screeding the floor primer is necessary to fill all the voids that exist, to create a continuous homogeneous structure. For this, deep penetration soils are produced, which are designed to strengthen the base to a depth of several centimeters.
Frees from construction dust
It is no secret that during the construction work a huge amount of dust is generated. Its small particles create a layer between the glued surfaces, interfering with their adhesion. The primer of the floor binds them.
Reduces base permeability
In other words, it does not allow the base to absorb moisture. This, in turn, reduces the consumption of leveling mortar, paint, glue.
Protects against fungal mold
This is true when creating high-quality flooring in rooms with a high level of humidity or for unheated buildings - arbors, summer kitchens, terraces, balconies, etc. Fungicidal and water-repellent additives give such protective properties to primers.
All this applies mainly to bulk and glued coatings, as well as in the preparation of the base for painting. In these cases, it is important to ensure good adhesion of the materials. The question naturally arises: "Do I need a primer on the floor before laying linoleum, laminate or wooden coatings?"
Under linoleum and laminate, the base is primed if it is planned to stick the coating to the surface so that it completely absorbs the glue. This must be done if linoleum is laid on a cement screed - to strengthen the surface and prevent its destruction during mechanical stress.
A primer for a wooden floor (plywood, chipboard) is also necessary. It should have antiseptic properties, especially in wet rooms, in which linoleum is often used. Before laying the laminate, the primer is not always necessary, but before leveling the base it is necessary. It depends on how firmly the leveling mix will combine with concrete, and as a result, its durability and coating quality.
Types of primers
According to the mechanism of action, these materials can be divided into compositions for surface application and deep penetration. You already have a general idea of the latter - they make the loose surface of the base stronger and strengthen it. Surface primers are designed to give the substrate good adhesion characteristics.
Most of these compounds contain very fine sand, which gives the surface a roughness: it is necessary for normal adhesion. Consider the classification of primers by composition.
Acrylic
This is the most common, universal primer for concrete floors and wooden surfaces. The material is very easy to apply, dries quickly, does not have an unpleasant pungent odor, dilution with water is allowed. It is used for repairs in new buildings. This is a primer for a floor under a tile, gypsum cardboard. The most popular among these compounds are mixtures from manufacturers Ceresit, "Elf", Olympic.
Alkyd
Primer for wood and metal surfaces. There are several varieties of such compounds:
- Zinc phosphate is an excellent and, according to experts, the best anti-corrosion primer for coating surfaces before applying alkyd paints.
- On zinc chromate, which has similar properties, but it has an extended range of applications. Excellent primers in this category are produced by Lazur, PolyFarb, Belinka.
Epoxy
It is a primer for screeding and processing concrete floors, especially when moisture protection is required. The compositions can be diluted with solvents, they have a high chemical resistance.
Polystyrene
The compounds are used for wooden coatings. The primer of this type is toxic, therefore it is necessary to strictly observe the safety instructions and to ventilate the room well.
Shellac soil
This is a special composition that is designed to impregnate a floor made from fresh coniferous wood. It does not allow resins to surface.
Multi soil
Reliable compositions, which are produced in a small series - Evro Primer Multi, Forbo 044, Uzin Pe 260. Primer for poured floors, screeds made of cast asphalt, stone and ceramics, mineral slabs, impregnated with bitumen, etc.
Features of choice
From the foregoing, it becomes clear that the primer should be selected in accordance with the characteristics of the material on which it will be applied. But at the same time, several factors should be taken into account - operating conditions and surface condition.
Concrete floor primers
Monolithic concrete does not absorb water well. This is evidenced by a shiny film on its surface. It is impossible to lay some kind of solution on it. For this reason, it must be sanded or (preferably) coated with a primer designed for poorly absorbent surfaces. As a rule, they have a milky color.
Sometimes finishers for safety insurance replace it with the composition "Concrete Contact". It is pink. This is a very popular primer. Under the bulk floor, it can also be used with success, since it forms a waterproof film that provides waterproofing of the base, which is very important when creating bulk floors, which differ in a very liquid structure.
Primer for polymer screeds
For epoxy bulk floors use polyurethane or epoxy primers. When buying, be guided by the recommendations of floor manufacturers. When purchasing a composition for bulk coating, read the manufacturer's recommendations for a primer for floor screed. This is especially important for polymer floors.
For cement-sand substrates
Such bases, as well as cement-based screeds, are primed with deep penetration compounds. They are almost colorless and slightly cloudy. Unstable bases and old screeds are covered with such materials.
Tile Compounds
Do I need a primer before laying tiles on it? Specialists will answer in the affirmative. Alkyd primer in this case is a universal composition. It is used for application on concrete, wood and other substrates. In this case, you can apply one of two types of compounds:
- Perchlorovinyl - when dried, it creates a film with moisture repellent properties. The composition prevents mold, the growth of fungus inside concrete.
- Glifthalova is a general-purpose primer with excellent anti-corrosion properties. It adheres well and significantly increases the strength of the base.
Application Rules
Usually with the application of a primer for the floor there are no difficulties. Processing horizontal surfaces is much easier. But before you start work, they must be prepared:
- dry well;
- clean from dirt and construction debris;
- if necessary, polish;
- degrease oil stains (if any) with a solvent;
- vacuum in conclusion.
After such preparatory work, immediately proceed to the primer before finishing the floor with the selected material. This is usually done in two to three stages. Their number depends on the degree of absorption of the base. When coating with the first layer, the primer is diluted so that it fills microcracks and pores.
The second and third layers are applied only after the previous one has completely dried. Typically, the manufacturer indicates the drying time on the packaging. You can’t reduce it, even if, in your opinion, the surface is already completely dry. At the same time, it is not necessary to stretch the breaks between the application of layers too much so that the dust does not settle on the surface. It is more convenient to apply a primer on the floor with a roller on a long handle or with a flat brush.
Primer floors: prices
Perhaps you can do this work yourself, but if you turn to professionals for help, they will evaluate their services as follows. In Moscow, the price range for this service is from 15 to 500 rubles per square meter, depending on the condition of the floor base and the composition used. The average price is within 65 rubles per square meter.
To summarize
Whatever flooring you choose for your home, of course, you want it to please you with beauty and durability for many years. This result can be achieved only with a responsible attitude to the preparatory work, in particular to the choice of composition and priming of the base.