- Properties and composition features
- Garage Benefits
- Varieties of compositions
- Surface preparation before application
- Application technique, consumption and gaining performance
- Old floor restoration
- What are the alternatives
So that the concrete floor is not dusty and has high wear resistance, additional surface treatment will be required. In addition to the classic concrete ironing, there are a number of other ways to achieve high performance. In particular, we propose to discuss polyurethane and similar polymer impregnations.
Properties and composition features
Polyurethane impregnation is supplied as a ready-to-use, low viscosity liquid. The composition is one-component, and does not require any manipulations before use, with the exception of simple mixing.
The majority of polyurethane impregnations, due to their high fluidity, penetrate deep enough into an array of concrete or sand-cement screeds, about 5–10 mm. The impregnation grabs quickly, as a result, the smallest pores are filled with plastic polymer, and the concrete acquires a very high strength.
The polyurethane molecule has a length sufficient for reliable binding of the fine fraction of the cement-sand massif. Thanks to this, it is possible to refuse the inclusion of fibers or various kinds of plasticizers in the original composition of concrete. The coating becomes dense enough without them and does not form small cracks, even with cyclic heating / cooling.
After complete polymerization, not only compaction and bonding of the top layer of the screed is observed, but also the formation of a glossy crust. You can walk on the floor the next day after application, after the next 2–3 days the polymerization takes place completely and the coating is ready to receive the full mechanical load.
There are two main risk factors for a garage floor. The first is mechanical damage both from a collision with a vehicle, and through negligence of a dropped tool. Compared to untreated concrete, polyurethane flooring has a strength that is increased by 2–3 times, depending on the specific composition used. Abrasion resistance also increases very, very noticeably: a one-time application even at service stations is enough for 5-6 years of active use, later the coating is easy to renew.
The second type of damage can be called the spill of any kind of technical automotive fluids: from fuel and oils to Tosol. Where concrete is usually subject to absorption and chemical degradation, the polyurethane gloss remains completely inert to any kind of solvents. Even after partial abrasion of the gloss, the structure of the top concrete layer remains tightly sealed, which means that it does not absorb anything and does not get dirty.
In the autumn-winter period, the problem of applying snow and dirt to the garage on the inner surfaces of the arches and the bottom of the car is very urgent. There is no way to remove moisture from an ordinary concrete floor, it is absorbed and it takes time to dry. From the floor covered with polyurethane, moisture is removed with a rag, or simply swept out through the gate into the street.
Varieties of compositions
In the domestic market, polyurethane impregnations for concrete are known under the trademarks “Elakor”, “Protexil” or “Polyplan”. In ordinary stores with building materials, such compositions can be found quite rarely: the supply is carried out by enterprises specializing in the manufacture of self-leveling floors, including through a network of local dealers.
Strictly speaking, polyurethane impregnation is not an independent coating. This is a kind of primer, which is impregnated with a concrete screed before applying the base compound. But since the floor in the garage has no special claims to the aesthetics of the appearance, the second stage is safely bypassed, limited to dust removal, structural strengthening and hydrophobization..
It is important not to get confused here: some types of impregnation may require preliminary priming, although they themselves serve as deeply penetrating primers. This, as a rule, is the manufacturer’s requirement and it is worth adhering to it objectively only when providing a guarantee.
The cost of the composition fluctuates around 200-300 rubles per liter, which, with an average consumption rate of 350-500 ml / m2 results in the cost of processing a single garage of the order of 5-7 thousand rubles. Foreign trains are about 30-40% more expensive due to delivery, but there was no obvious benefit from their use in the context of technical premises.
Surface preparation before application
Although polyurethane resin has extremely high adhesion to concrete, concrete must be free of any kind of contamination. Oil, greasy and other stains must be removed by any convenient method, they prevent the absorption of the composition and negatively affect the appearance, because the impregnation is almost completely transparent.
One of the requirements for surface preparation is manual cleaning of the concrete surface from the film of cement laitance, which is poorly permeable to any liquids. This is a fairly simple task, it is enough just to rub the floor well with the laid flat emery wheel, applying medium effort.
The composition can be applied only after the concrete has gained full strength and the hydration of the cement is completed. The moisture content of the floor should not be high, the allowable limit is 3–3.5%. All concrete grades are suitable for those in the range between M100 and M400. Although most manufacturers allow the processing of M100 concrete, it is better to refuse such a practice. This grade is used for preparatory work, it does not have enough density and hardness, over time, large cracks may appear.
As for grades higher than M400, their impregnation does not bring tangible benefits due to their natural high strength and low dustiness. The properties of such a coating can be significantly improved only by pouring a two-component compound.
Application technique, consumption and gaining performance
After the primer has dried, the floor is swept once more, wiped with a slightly damp cloth and dried for 20-30 minutes. The polyurethane impregnation is especially convenient because it can be used in truly field conditions: at temperatures down to -20 ° C and relative humidity up to 90%. Very handy for working anywhere in a remote garage co-op.
Contacting with air, the impregnation emits volatile compounds, so you should work with it in a respirator. The composition is applied with a roller or brush, there are no special tricks in this process..
In the first 1.5-2 hours after application, it is important to monitor the condition of the floor. If it starts with spots indicating uneven absorption, the application must be repeated. The secondary coating is characterized by a much lower consumption, it can be carried out 3-4 hours after the first, when the resin has already set and does not stick to hands, but has not yet completely polymerized.
Old floor restoration
Old and partially destroyed concrete floors can also be impregnated to improve the strength characteristics. Of course, they should be covered with a prep screed first, but this is entirely in your interests. The fact is that the old floor has a high absorption and the consumption will be very high. Thin cement screed will cost much less.
It will also help eliminate wide cracks and general unevenness in the pavement, potholes and signs of damage. It is important that the screed layer is not too thick; a DSP grade of the order of 200–250 will work very well. Polyurethane will impregnate such a screed well and reliably bind it to a deeper layer.
If the floor has already been impregnated, before renewing it, it is necessary to first “knock down” the gloss for more reliable adhesion. This is done mechanically: angle grinder with a flap wheel or an orbital sander.
What are the alternatives
Besides polyurethane, there are many other formulas for pouring and impregnating concrete floors. Polyurethane is preferable in terms of its simplicity and cheapness, but its performance is far from ideal, and its appearance is not too pretentious..
A more serious or even extreme load (for example, from a truck or tracked vehicle) can withstand self-leveling floors based on epoxy resins, acrylic or alkyd polyesters.