How to make a floor screed with your own hands?
Do-it-yourself floor screed is a task that you can face if you decide to make a major overhaul in an apartment or a private house. It can be fine and rough, for wet and dry rooms, hard and floating, dry, semi-dry and traditional wet. A rough screed is understood as a leveling layer of cement-sand mortar over the floor slab, slight irregularities are allowed, since it involves additional leveling in the next step.
The finishing screed is the finishing layer of the floor finish, it must be perfectly even and can serve as an independent coating, or as a basis for laying floor coverings (linoleum, laminate, carpet, etc.), as a rule, self-leveling mixtures are used to create it. The main functions of the screeds are surface leveling, if necessary, creating slopes, giving the surface strength and rigidity, as well as heat and sound insulating properties. In this article we will tell you how to properly make a floor screed and what are its features for rooms for various purposes.
Types of screeds
Screeds are classified depending on the main material included in their composition. Do-it-yourself floor screed can be concrete, magnesite, anhydride, asphalt, mosaic, based on gypsum and epoxy resins. Currently, there are many different types of ready-made dry mixes on the building materials market with which you can make a floor screed with your own hands.
Screed for wet rooms
For wet rooms, the composition of the screed will be slightly different. Let's look at how to make a floor screed in the bathroom. A prerequisite is the creation of waterproofing. As a waterproofing layer, it is recommended to use a modern material - euroroofing material. This roll material is laid in 2 layers dry with overlapping joints.
Important! Bring the edges of the waterproofing onto the wall to a height of 5-7 cm. This will protect the joints between the walls and the floor from leaking.
After that, beacons from metal profiles are laid on a concrete solution strictly according to the level. Wet room mortar is made from three components: sand, cement and a dry waterproofing mixture, which is sold in bags. (for example manufacturer Ceresit). The video shows in detail the process of making a concrete screed in the bathroom:
Screed for underfloor heating
To install a warm floor, a cable or pipes (in the case of a water heated floor) are laid out on the surface, and then they are poured with a 1: 3 cement-sand mortar with the addition of reinforcing additives.
The video shows how to properly make a floor screed for water heating:
floating screed
This type takes place if the floor slab needs additional heat and sound insulation. The solution is laid on top of thermal insulation and sound insulation on a special layer (you can use a polyethylene film with a thickness of 0.1-0.15 mm). The layer performs the function of separating the solution and insulation. For a floating screed, a cement-sand or calcium-sulfate mortar is used.
It is recommended to use a damper tape, which is glued at the junction of walls and floor around the entire perimeter of the room, taking into account ledges and columns. It protects the surface from cracking during concrete shrinkage, and also increases the sound insulation of the room. The height of the overlap of the tape on the wall is taken in accordance with the total thickness of all layers of the future floor.
Video. floating floor. Types of solutions, pouring methods, nuances, subtleties:
Dry and semi-dry screeds
In the case when it is required to carry out repairs in an accelerated time and there is no time for the traditional wet screed to fully dry, it is possible to perform a rough screed using a semi-dry method. To do this, a small amount of water is added to the cement-sand mixture, sufficient to obtain a loose concrete mass after kneading. It is also necessary to perform reinforcement with the addition of fiberglass to the composition of the solution. After that, the mixture is applied to the base with the rule aligned with the beacons, and then the surface is polished. This technology is most quickly and efficiently performed by a mechanized method.
Dry screed is a backfill of dry filler - quartz sand or expanded clay, on top of which plywood, or chipboard, GVL is mounted. This technology provides good sound insulation, light weight of the structure, no wet work in the room, and therefore no dirt and the risk of fluid leakage from the mortar into the ceiling. This type of screed is easy to do with your own hands, because. it is easy to manufacture, does not require machine mechanisms, special equipment and special care, however, it is afraid of moisture, and if it enters the structure, swelling of the floor, surface deformation and the formation of irregularities can occur.
Video. Dry screed technology. This method is suitable if you need to meet a tight deadline and do not want to mess with a liquid solution:
Finishing screeds
Finishing screeds often use factory-made finishing self-levelling mixtures. They are cement and polymer based. Self-leveling floors are easy to care for, they form a durable, even and smooth surface that is easy to clean. Bulk floors are divided into types depending on the binder that is used in their composition. There are methyl methacrylic (MMA), polyurethane, polyurethane-cement, acrylic-cement and epoxy compounds.
Advice! The strength grade of the finish coating should not be higher than the grade of the rough screed solution on which it is laid. Otherwise, deformation and delamination will occur over time.
Video. Finishing screed device using a self-leveling mixture:
Screed laying technology
Let us consider in more detail the device of a traditional wet screed using concrete as an example. Do-it-yourself floor screed is performed using the following tools:
- building level;
- rule;
- beacons (guides);
- drill with a nozzle for mixing the solution;
- putty knife.
Depending on the purpose of the room and the materials used, the technology will vary. Consider the stages of this process:
- preparation of the base, primer;
- thermal insulation (if necessary);
- waterproofing (if necessary);
- reinforcement (if necessary);
- placement of beacons (guides) with leveling;
- mixing the solution;
- filling;
- surface care.
The first step is to prepare the foundation. It must be dedusted, garbage removed, in the presence of dirt and stains of oil, bitumen, it is necessary to remove them. If there is an old dilapidated screed, it must be dismantled. After that, it is necessary to treat the surface of the floor slab with a primer using a roller or brush and allow to dry for 5 hours. If there are water and sewer pipes in the room, then you need to lay them out on the floor.
For thermal insulation of the room, you can use expanded clay or expanded polystyrene, the main thing is that the surface of the insulation is rigid. If the floor screed is done on a soil base with your own hands, then first you need to lay a layer of expanded clay, and then a layer of sand, with the obligatory compaction of each layer. For greater effect, it is recommended to moisten with water.
Waterproofing is usually carried out in wet areas (where there are connection points for plumbing and sewer systems). To protect against dampness, waterproofing is also sometimes arranged in the premises of the first floor, basements.
After that, reinforcement is performed. It is used in the event that the surface is planned to be subjected to heavy loads. To do this, use reinforcing bars, the cross section of which is selected depending on the planned load (diameter value in the range from 8 to 20 mm), or reinforcing mesh (bar diameter 6 mm). Sometimes plastic reinforcing meshes are used instead of metal ones. Reinforcing meshes will also help to avoid deformation of the concrete layer and cracking in case of shrinkage of the building. Concrete is a brittle material and does not work well in bending and tension, reinforcement allows you to eliminate these shortcomings and protect the surface from cracks.
After that, the placement of beacons (guides) is performed. They should be set clearly in accordance with the building level, tk. the subsequent flatness of the surface depends on this.
The next step is to pour the solution. When the screed is ready, it is left for a while until completely dry. Do not forget to take care of the screed during this time, periodically spraying it with water. Concrete slowly gains its strength (within 27 days), it must harden gradually. If it dries too quickly, cracks may form. Therefore, as a care, you need to moisten the finished screed with water 2 times a day for a week, and then cover it with plastic wrap and leave it for 2 weeks.