Gypsum self-leveling floor is a dry building mix, which, in addition to the base material, includes quartz sand and special plasticizing additives that increase the plasticity of the solution. The finished coating has a high curing speed. Therefore, all pouring work must be completed in a short time so that the floor retains its performance characteristics for a long time.
Properties and main features
The difference between self-leveling floors and other types of screeds is that they require very high quality preparation of the base. Under them, waterproofing and insulating materials are not laid so that adhesion to the bearing surface does not decrease.
The self-leveling floor is very expensive. Usually it is equipped with a thin layer in combination with cement or gypsum. This is a more affordable option. Gypsum self-leveling floor is cheaper, as itmaterial is considered relatively inexpensive. But its distinguishing feature is the high speed of solidification.
Adhesion of the solution to the base occurs after 5 minutes after the preparation of the solution. It is allowed to use the material for 10 minutes without loss of quality, and after 20 minutes it already becomes unusable. To slow down the hardening process a little, a solution of borax is added to the mixture.
The composition of the gypsum self-leveling floor from different manufacturers does not have significant differences. Therefore, there can be no strict recommendations regarding companies. The basis of any mixture is gypsum and quartz sand.
Advantages and disadvantages
The unique feature and main advantage of the gypsum mixture is its curious ability. First, it absorbs moisture, and then give it away, maintaining the optimum level of humidity in the room. Other advantages of a gypsum-based self-leveling floor include the following:
- This coating is absolutely uniform and smooth. It hardens much faster than a cement-based bulk screed, so the likelihood of bumps and cracks is minimized.
- The finished mixture spreads very evenly over the finished base.
- Gypsum coating regulates the humidity in the room, as it can not only absorb excess moisture, but also give it away if necessary.
- Gypsum mixture can be poured not only with the help of special machines, but also manually.
I havegypsum composition and some disadvantages. Despite the fact that it can absorb moisture, it cannot absorb a large amount of water in the room. From this, it will quickly collapse, so it is not recommended to equip a gypsum-based coating in the bathroom and in the kitchen. Another disadvantage is that the gypsum screed is incompatible with the adhesive solution. It must not be laid as a base for a tile floor.
Preparing the base
Gypsum self-leveling floor requires high-quality leveling of the base. There are four ways to pre-prepare the surface:
- Contact coating. This method consists in the fact that after a thorough cleaning of the base, it must be primed. To do this, along the perimeter of the walls, the edge tape is laid out and fixed, and then it is treated with a primer to the height of the future self-leveling floor.
- Filling the floor with separation layer equipment. In this case no priming is required. Paper is laid on the prepared surface (it must be rolled out over the entire area). The material is sold in rolls, it is necessary to calculate in advance how much it will be needed for the entire surface. Tapes are overlapped by 10 centimeters.
- Laying special waterproofing material. The installation method is identical to the separation layer equipment, but waterproofing is used instead of paper. Surface priming does not apply here either.
- Pouring gypsum mixture on the warm floor. Heating does not harm the composition, as it has good resistance to temperature stress.
Required tools
To apply the gypsum mixture to the floor, a squeegee with a steel sheet is used. This is a special spatula with teeth that quickly form a screed of the required thickness.
Beacons are used as beacons that help to monitor the uniformity of coverage. In any solution, bubbles form when the composition is mixed with water. After hardening of such a screed, pores may remain on the floor, which will damage the coating and make it less durable. Remove these bubbles from the floor with a spiked roller.
To level the mortar on the floor, you have to walk on it in shoes with studded soles (paint shoes). Do not step on a still wet floor without these shoes, otherwise dents will form on the surface.
To protect the screed from cracking when it dries, a damper tape is fixed along the perimeter of the wall. Also, for the work you will need: a level, a construction mixer, a primer, a roller and a plastic bucket.
Preparing the solution and carrying out the work
Not everyone knows how to properly fill the self-leveling floor. For work, it is necessary to prepare a mixture of dry powder and water. It is important to observe all proportions, otherwise the coating will not be of high quality. A properly mixed solution resembles condensed milk in consistency. The amount of water depends on the composition chosen.
The powder is poured into water at room temperature and thoroughly stirred until the mixture acquires a uniform consistency. You need to mix the composition for at least 3minutes, then let it stand for 7 minutes and stir again.
When the solution is completely ready, it is carefully poured onto the prepared surface and spread over the entire area with a doctor blade. Using a needle roller, the surface is carefully leveled and allowed to dry. The entire operation is given no more than 30 minutes, otherwise the gypsum-based composition will harden.
The pouring of the self-leveling floor should be carried out with the windows and doors closed to protect it from drafts. Also, direct sunlight is harmful to him, so it is better to hang light curtains on the windows. Drying should occur naturally, do not use heaters, this may cause cracks on the surface.
Not the last role in the arrangement of the coating is played by the question of how much the gypsum self-leveling floor dries. Professionals do not recommend exposing this surface to a load earlier than after 12 hours. For greater reliability, it is better not to walk on the surface for 24 hours.
Filling work can be done independently. Usually on any package there is an instruction for preparing the composition, all proportions are clearly spelled out there. If you have doubts about your own abilities, it is better to entrust the work to specialists.
Recommended by professionals
A strong and even coating will be obtained if you follow certain rules during installation. The gypsum-based composition hardens quickly, so it is recommended to divide the flooring in a room of more than 9 m² into several stages. Each section is filled in turn. The uniformity of the layers is checked using a level.
To prepare a solution from a ready-made mixture, which can be bought at hardware stores, you need to use tap water. The pouring job is best done in 20 minutes (deadline is 30 minutes).
The temperature in the room where the floor is being poured should not be less than +5°C. During all work, you must use a respirator, goggles and gloves.
