Making a wet screed for the floor is easy, but quite laborious. In this review, we will consider in detail all the features of this work. The first question to be decided is what is a wet floor screed? By it today we mean the top layer of material laid on top of the floors. As a rule, it is used to level the floors in different rooms, and also makes the surface even for the subsequent laying of the topcoat.
Features
Let's take a closer look at this. How is the installation of a wet floor screed? This type of screed is laid on any type of floor, including bare ground. Installation of a wet screed can be carried out on top of a layer of thermal and waterproofing. The mount is suitable for installing all kinds of finishing materials.
Wet floor screed has a number of disadvantages. These include:
- heavy weight;
- long timehardening - up to 90 days;
- time of complete drying - from six months;
- coating durability depends on adherence to technology and quality of materials.
However, all these disadvantages of a wet screed are more than offset by the result.
There are two options for arranging the mount. In the first case, it is made as an independent part lying on the floor. In the second case, it is necessary to achieve a strong adhesion of the base and the screed. If you plan to install underfloor heating at home, then it is better to use the first option. When the temperature changes, the plate must be able to "breathe".
Before pouring, a damping tape is installed around the perimeter of the room, and then a heat-insulating layer. In order for the screed to be strong enough, it must have a significant thickness. Otherwise, its service life will be short. The thickness of a wet underfloor screed is usually 8-10 cm.
Production steps
Let's take a closer look at this aspect. How is a wet floor screed made? The technology involves the following steps:
- Preparing the base.
- Installation of beacons.
- Preparing the solution and pouring it.
- Screed finishing.
If you decide to do the arrangement of a wet screed yourself, you need to figure out how each stage of installation is carried out.
Preparing the base
Before pouring the screed, it is recommended to carefully sweep the base. Dried tosurface pieces of mortar should also be removed. For laying on a layer of thermal insulation, this will be enough. If you need the screed to adhere well to the base, the surface should be well treated: sweep thoroughly with a damp broom, prime with an acrylic-based compound, treat the concrete with contact. Be sure to check the floor for cracks and holes, otherwise the mortar may leak to the neighbors.
Installing beacons
What is it for? To make the wet floor screed smooth, you need to install beacons. The horizontality of the final surface depends on how carefully you perform the work at this stage. Galvanized profiles are best suited for lighthouses. They have the required rigidity. You can also use ordinary plaster beacons, the thickness of which is only 9 mm. Experienced builders use alabaster to install them. This material hardens quickly. But you can use simple gypsum plaster. It is comfortable, plastic, and you can install beacons in it with millimeter accuracy.
Filling the screed
So what do you need to know about this? After completing the preparatory stage, it is worth starting to pour a wet screed. The procedure can be greatly simplified if you set up a kind of conveyor for the preparation of a cement mixture. It should have a uniform composition and consistency. Excess water in this case is useless. You should start from the far wall of the room and graduallymove towards the door. The surface of the screed should be leveled according to the level of the beacons using the rule. It will begin to exfoliate and release water. There should be no puddles on the surface of the screed. Get ready for a tedious and dirty job.
Finishing
After pouring the screed, give it a day to harden. At this stage, beacons are extracted. Cement mortar is also poured into the recesses remaining after them. Further work with the screed will depend on the type of topcoat being laid on it. If it is a tile, then the work can be completed. Some coatings require a perfectly flat surface. In this case, the screed will need to be additionally rubbed with a grater and fresh mortar.
When can I start walking on a freshly laid screed? Already after a day, they recommend trying to take the first steps, but for complete hardening, it is advisable to withstand the coating for four weeks at normal air temperature. Only then can you start laying the finish coat. It should be noted that at lower temperatures, hardening will proceed more slowly. How long does a wet floor screed dry on a balcony? It depends on the ambient temperature and humidity.
Drying the hood is a different process. The thicker the coating layer, the longer it will dry. Low temperature and high humidity can significantly slow down drying. If residual moisture does not play a special role for laying ceramic tiles, then for parquet it is a very significant factor.
Minimum set of tools
How to make a wet screeddo-it-yourself floor? For work you will need:
- primer brushes;
- 20 liter buckets for making mortar;
- electric concrete mixer;
- level;
- spatulas;
- rule.
If we are talking about pouring the screed in a small area, for example, in a bathroom, then you can do it on your own. It is not possible to fill a large area alone. A wet floor screed in a panel house apartment can turn into a whole problem if you don’t prepare. It will be necessary to find and repair all targets and cracks in the ceiling. It is not always possible to do this, so it will be easier to just cover the floor with a layer of polyethylene. The edges of the film are raised by 20-30 cm. In this case, not a drop of solution will leak to the neighbors.
Materials
So what do you need to know about this? The quality of the resulting coating will depend on the materials used. A wet screed for underfloor heating in an apartment can be prepared from a mixture of sand and cement. Particular attention should be paid to the sand used. It should not contain impurities of clay. The quality of cement is more difficult to check. It is best to use ready-made cement-sand mixtures. You can find detailed cooking instructions on the package.
As a filler, crushed expanded clay or bedding can be added to the mixture. This will reduce its consumption. In addition, expanded clay will easily take away excess water, and when it hardens, it gives it away. Such a screed with a backfill practically does not crack. Be sure to thoroughly mix each portion of the mixture. With careless mixing, the strength of the material is significantly reduced. If you doubt the quality of the dry screed mix, you can pour 2-3 handfuls of Portland cement into a serving.
Semi-dry screed
What is her speci alty? The composition in this case will be identical to the wet screed. The only difference is the level of moisture content. Based on the name, we can conclude that in this case half the amount of water is required.
As for the technology of laying a semi-dry screed, it is also slightly different. The composition is evenly distributed over the designated area. Laying is carried out in several layers, each of which is properly compacted. When the screed reaches the desired level, the excess can be removed using a rule. After 2-3 hours it is allowed to walk on the surface. At this time, the final leveling and surface treatment with a metallic brush is performed.
The choice of the type of screed must be done, taking into account their features. The semi-dry method has a number of distinguishing characteristics:
- high density;
- no need for reinforcement;
- easy installation;
- shrinkage during drying;
- possibility of mounting the finish coat immediately after the surface has dried and hardened.
Semi-dry or wet floor screed have one significant drawback - the weight of the finished structure. It can create a serious load on the floors, and this should definitely be taken into account.
Dry screed
Let'sLet's look at this aspect in more detail. Dry or wet floor screed - which is better? This question is of interest to many owners of private houses and city apartments today. The installation technology of a dry screed is significantly different from wet and semi-dry. In this case, loose heat insulator and sheet materials are used. Here is an approximate order of work:
- Wooden slats or logs are laid out on a concrete base or a rough screed.
- After aligning the lag in the horizontal plane, the elements are fixed. For this purpose, it is best to use metal corners designed for roof assembly.
- Expanded clay is poured into the space between the lags.
- Sheets of plywood, OSB or chipboard are laid on the backfill. They are attached to the rails with self-tapping screws, and are attached to each other with special glue.
Expanded clay is a light, porous material made of fired clay. It has excellent sound insulation and will retain heat well in the room. In addition, expanded clay is a "breathable" material. In the room where such a screed is used, there will always be an excellent microclimate. The screed will not mold or rust. Experts also note the fire-resistant properties of expanded clay.
Compared to wet and semi-dry screed, dry screed is much easier to install. This will help reduce the load on the floor or foundation. In addition, this technology will cost you much less. The advantages of dry screed can also beattributed to:
- Installation speed: all screeding work can be done in one day with your own hands.
- The materials used provide good heat and sound insulation properties.
- Dry screed is considered the most acceptable option when planning the installation of a floor heating system. In the event of a malfunction, the design is easily disassembled.
- With this screed you can level the floors even with large differences in height. The mixture layer can be any thickness, because it will still remain light.
- Any type of floor finish can be laid over the dry screed.
- Such floors will help to significantly save on heating in the cold season.
A dry screed has its drawbacks. These include the possible formation of dust during strong impacts on the base. Therefore, if you have people in your family who suffer from asthma, this option is not recommended. If water gets on the coating, problems can also occur. The top layer of the coating will have to be disassembled to dry the expanded clay. This may cause some inconvenience. Therefore, dry floor screed is not recommended in rooms with high humidity: in the bathroom, kitchen and toilet.
Which one to choose?
Now that we have analyzed the features of the laying technology of all types, you can try to answer the fundamental question: which floor screed is better - dry or wet? It is impossible to answer it unambiguously. Each type is suitable for certain rooms. For example, dry screedsit is recommended to use in the presence of wooden floors in those rooms where the possibility of water and high humidity is excluded. Wet floor screed can be used in the kitchen, bathroom or toilet. Also, this screed is suitable for arranging a garage. Self-levelling compound is best for laying flooring in a residential area.
Conclusion
In this review, we examined in detail what are the different types of floor screeds. In total, there are three types: wet, semi-dry and dry. The most troublesome thing is a wet floor screed. The technology of its laying is quite complicated and takes a lot of time. The quality of the resulting coating depends on many factors: surface preparation, the quality of the composition used, and the ambient temperature. In addition, it is rather difficult to carry out the installation of such a screed on your own.
Semi-dry screed, as the name implies, differs from wet screed in terms of moisture content in the composition. The laying procedure here will also be slightly different. For example, a semi-dry screed requires careful tamping. Such a coating dries much faster.
The easiest option is to lay a dry screed. It provides good sound and heat insulation characteristics. However, for rooms with a high level of humidity, it is better not to use such a screed.
