No finishing work can do today without this material. The primer is a liquid composition designed to improve the adhesion of various materials. This bond is called adhesive.
Adhesion is the ability of various building materials to firmly bond together. If we talk about the primer of the floor, such a composition improves the adhesion of the screed to the base, strengthens the laying of tiles, etc. The primer also prevents moisture from being absorbed into the substrate, resulting in the screed drying more evenly, reducing the risk of cracking.
And that's 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 construction dust. Floor primer is needed for different surfaces. Which composition is suitable for a particular surface, we will tell in this article.
Do I need a primer?
Not all people who are far from construction work understand why a floor primer is needed, for example, before laying tiles, creating a bulkcoatings, etc. It would seem that the finishing layer completely hides all the flaws of the base, and the entire load ultimately falls on it.
That's true, but only partly. The thing is that the quality of the finish coating just 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 behind over time and most likely deform. To prevent this from happening, a floor primer is required. Let's take a closer look at what other functions this material performs.
Strengthens structure
For example, if the base of the floor is loose, porous, layered, before screeding, a floor primer is necessary to fill all existing voids, creating a continuous homogeneous structure. For this, deep penetration soils are produced, which are designed to strengthen the base to a depth of several centimeters.
Free from building dust
It's no secret that huge amounts of dust are generated during construction work. Its small particles create a layer between the surfaces to be glued, preventing their adhesion. The floor primer 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 mold growth
This is true when creating high-quality flooring in rooms withhigh level of humidity or for unheated buildings - gazebos, summer kitchens, terraces, balconies, etc. Such protective properties of primers are given by fungicidal and water-repellent additives.
All this applies mainly to bulk and glued coatings, as well as when preparing the base for painting. In these cases, it is important to ensure good adhesion of the materials. Naturally, the question may arise: “Do I need a floor primer before laying linoleum, laminate or wood flooring?”
Under linoleum and laminate, the base is primed if the coating is planned to be glued to the surface so that it completely absorbs the glue. This must also be done if linoleum is laid on a cement screed - to strengthen the surface and prevent its destruction under mechanical stress.
A primer for a wooden floor (plywood, chipboard) is also needed. It should have antiseptic properties, especially in wet rooms, in which linoleum is often used. It is not always necessary to prime the floor before laying laminate flooring, but it is necessary before leveling the subfloor. It depends on how firmly the leveling mixture will connect with concrete, and as a result - its durability and quality of the coating.
Types of primers
These materials according to the mechanism of action can be divided into compositions for surface application and deep penetration. You already have a general idea about the latter - they make the loose surface of the base more durable, strengthen it. Surface primersdesigned to give the substrate good adhesion characteristics.
Most of these compounds contain very fine sand, which gives the base 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, 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 renovations in new buildings. This is a primer for the floor under the tiles, drywall. The most popular among these compositions are mixtures from manufacturers Ceresit, Elf, Olympic.
Alkyd
Primer for wood and metal surfaces. There are several varieties of such compositions:
- Zinc phosphate based - excellent and according to experts the best anti-corrosion primer to coat surfaces before applying alkyd paints.
- Based on zinc chromate, which has similar properties, but it has an extended range of applications. Excellent primers in this category are produced by Lazur, PoliFarb, Belinka.
Epoxy
This is a primer for floor screeding and concrete flooring, especially when moisture protection is required. The compositions can be diluted with solvents, they have high chemical resistance.
Polystyrene
Compounds used for wood flooring. This type of primer is toxic, so you must strictly follow the safety instructions and ventilate the room well.
Shellac primer
This is a special composition that is designed to impregnate a floor made from fresh softwood. It does not allow resin to come to the surface.
Multiprimers
Reliable compositions that are produced in small series - Evro Primer Multi, Forbo 044, Uzin Pe 260. Primer for self-leveling floors, screeds from poured asph alt, stone and ceramics, mineral plates 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 some 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. No solution should be placed on it. For this reason, it must be sanded or (preferably) primed with a primer designed for slightly absorbent surfaces. As a rule, they have a milky color.
Sometimes finishers for safety net replace it with the composition "Betonokontakt". It is pink in color. This is a very popular primer. Under the self-leveling floor, it can also be successfully used, since it forms a waterproof film, whichprovides waterproofing of the base, which is very important when creating self-leveling floors, which are characterized by a very liquid structure.
Primer for polymer screeds
For epoxy self-leveling floors, polyurethane or epoxy primers are used. When buying, be guided by the recommendations of floor manufacturers. When purchasing a self-leveling coating, read the manufacturer's recommendations for a primer for floor screed. This is especially important for resin floors.
For sand-cement substrates
Such bases, as well as cement-based screeds, are primed with deep penetration compounds. They are almost colorless and slightly cloudy. Fragile bases and old screeds are covered with such materials.
Compounds for tiles
Do I need to prime the floor before laying tiles on it? Experts will answer this question 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, one of two types of compositions can be applied:
- Perchlorovinyl - when dried, it creates a film with water-repellent properties. The composition prevents the appearance of mold, the reproduction of fungus inside the concrete.
- Glyphthalic is a general purpose primer with excellent anti-corrosion properties. Good adhesion and significantly increases the strength of the base.
Application rules
Usually, applying a floor primer is no problem. It is much easier to process horizontal surfaces. Butbefore starting work, they must be prepared:
- dry well;
- clean up dirt and debris;
- if necessary, sand;
- degrease oil stains (if any) with solvent;
- finally vacuum.
Having done this preparatory work, immediately proceed to the primer before finishing the floor with the selected material. This is usually done in two or three steps. 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 cannot reduce it, even if, in your opinion, the surface is already completely dry. At the same time, do not stretch the breaks between applying layers too long so that the dust does not settle on the surface. It is more convenient to apply a primer on the floor with a long-handled roller or a flat brush.
Primer floors: prices
Perhaps you can do this work on your own, but if you turn to professionals for help, they will appreciate 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 subfloor and the composition used. The average price is within 65 rubles per square meter.
Summarize
Whatever flooring you choose for your home, of course you want itdelighted you with beauty and strength for many years. Such a 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.
