Cement for floor screed: which is better to use?

The strength and caliber of your flooring can be greatly affected by the type of cement you use for your floor screed. The primary binding agent in screed, cement gives the material its strength and durability against deterioration. Knowing the various varieties of cement that are available and their unique qualities will assist you in making an informed choice that best meets the requirements of your project.

The type of aggregate you intend to use is one of the most important factors to take into account when choosing cement for floor screed. Whether you use gravel, sand, or a mix of the two, the cement must properly bind the materials to create a level, sturdy surface. An important factor in determining the strength and long-term capacity of the screed to support heavy loads is the ratio of cement to aggregate.

The cement’s setting time is another crucial component. Rapid-setting cement expedites the screeding process, saving time and facilitating quicker access to the freshly laid floor. On the other hand, larger projects that require longer workability to achieve a smooth finish without sacrificing strength might benefit more from slower-setting cement.

It’s also crucial to take the surroundings into account when applying and curing. To ensure proper curing and avoid cracking or uneven drying, certain types of cement are better suited for use in colder or more humid environments. You can maximize the longevity and performance of your floor screed and guarantee a strong and long-lasting base for your flooring by selecting the appropriate cement formulation.

Purposes of use

When cement comes into contact with water, it transforms from a powdery substance into a plastic mass that can be used to fasten construction-related items. It becomes strong and dense, resembling rock after it has dried.

The primary ingredient in concrete mortar is cement, which is made up of cement, water, sand, and occasionally other contaminants like plasticizer.

This ingredient, when combined with the other ingredients to form concrete, is ideal for pouring floors because it is easily leveled when liquid. Cement gains strength when it hydrates during drying and takes on a crystalline structure.

Composition requirements

Fundamental specifications for the flooring cement mixture specified in:

  • GOST 31358-2007;
  • characteristics for various grades of cement are regulated by GOST 31108-2003 and GOST 30515-2013.

These documents specify the qualities that dry cement ought to have both during and after the hardening of the concrete mixture.

For instance, adhesion (adhesion strength) with the floor covering for load-bearing mixtures that have hardened for 28 days should be 0.75 MPa, and shrinkage deformation should not exceed 1 mm/m. The thickness of the floor covering determines the largest size of aggregate grains in the cement mixture; this number should not exceed ¼.

Large grains should not make up more than 5% of the content in concrete mixtures and no more than 2.5% of the dispersed (powder) material. Dry cement has a bulk density of 1000–1200 kg/m3, however this value can change based on the storage conditions of the mixture.

Incorrect storage causes the density to rise to 1700 kg/m3, which can give the concrete mixture additional properties (like becoming heavier or less durable).

What types are used?

For floor screeds, Portland cement of various grades is typically utilized because it has the best strength after hardening. For mixtures used in concrete floors, you can use:

  1. Cement grade M150-200, if you plan to pour the solution in small living spaces in which there will be no heavy loads. It is used to level the surface before laying the floor covering.
  2. M300-400 cement is used for office buildings, as it has high strength (M400 can withstand loads of up to 40 MPa after drying) and good hardening speed. Also, cement grade M400 is used for semi-dry screed, which reduces the load on the floors and hardens within 3 days (28 for full strength gain), which allows you to speed up the work on laying the floor covering.
  3. For industrial complexes with high loads on the floor covering, cement of a grade no lower than M500-600 is used.

Because M500’s high strength class allows it to be diluted more with sand and water, saving on solution, it can be used for a variety of premises. This brand requires a ratio of 1:4 for the mass of powder to sand, whereas M400 already requires a ratio of 1:3.

Two varieties of ready-mixed concrete exist:

  1. Homemade. In this case, cement of the required brand is taken and mixed independently in the required proportions with sand and other necessary materials. The advantage of this mixture is that you can regulate the amount of materials that are used for the solution, since in some cases more or less sand is needed.
  2. Ready dry mix is produced at the factory, which is why it more correctly maintains the required proportions of all materials that are needed to create durable concrete. The disadvantage of such a product is the inability to change the composition of the mixture, as this will damage the finished concrete. Often, water-repellent additives or varnishes can be added to such mixtures, which is why such cement can be used for rooms with high humidity, for example, a bathroom, since these substances prevent water from seeping out even when the floor is flooded.

The most famous brands

A few brands like M400 and M500 are among the greatest choices.

Rusean NC-20

Because Rusean NTs-20 (straining) has strong water-repellent qualities, it is used in rooms with high humidity. Suitable for bathrooms, garages, and basements as well. This kind of cement has a frost resistance of F and a waterproof class of W10. 25 kg at an average cost of 330 rubles.

Eurocement CEM II/A-SH 32.5H

Is among the best the M400 brand has to offer. Slag additives are present, accounting for 6-20% of the total mass. This is why concrete screed, bricklaying, and foundation pouring are all done with this kind of cement. cost 690 rubles for every 50 kg on average.

Holcim Extracem 500

Holcim Extracem 500 stands out among the M500 brand because its concrete has exceptional strength and ductility.

It is made using "dry" technology, in which every component is simultaneously ground and dried in a ball mill. For 50 kg, the average cost is 490 rubles.

De Luxe CEM I 42.5 M500

Utilized when building buildings that might be subjected to aggressive materials. possesses great strength and temperature resistance, much like other types. The average cost for 50 kg is 360 rubles.

The importance of making the right choice

Selecting the incorrect cement for the screed can cause it to crack during the hardening process and harm any communications embedded in it. This decision will also affect how long the floor lasts because concrete will distort under heavy loads, which could lead to the collapse or damage of the ceiling or floor covering.

In order to achieve a level and long-lasting surface in construction projects, selecting the appropriate cement for floor screed is essential. The strengths and characteristics of various cement types, such as Portland Pozzolana Cement (PPC) and Ordinary Portland Cement (OPC), vary and have an impact on the performance of screeds. PPC includes pozzolanic materials for better workability and lower heat of hydration, while OPC is recognized for its high strength and quick initial setting time, making it perfect for projects with a tight deadline. By being aware of these variations, builders can choose the best cement for a given project while maintaining structural integrity and economy when using floor screeding.

Useful video

Some advice on selecting cement in the video:

Of course! This is a brief summary of your article "The Best Type of Cement for Floor Screed: Which to Use?"

Selecting the appropriate cement for your floor screed is essential to guarantee a strong and long-lasting base. Depending on the needs of your project, different types of cement, such as Portland cement, blended cement, and fast-setting cement, each have unique benefits. Portland cement is still a preferred option for the majority of general applications because of its strength and adaptability.

Rapid hardening cement is appropriate for urgent projects or repairs because it sets faster than Portland cement, which makes it perfect for hurried construction schedules. Blended cements provide improved workability and a smaller environmental footprint by blending Portland cement with additives like fly ash or slag.

Think about things like setting time, strength specifications, and environmental effects when choosing which cement to use. Your floor screed’s performance and longevity can be further enhanced by using appropriate mix proportions and curing methods.

In the end, the cement you choose should fit your project’s needs and budget. You can make an informed choice that enhances the overall quality and longevity of your flooring project by being aware of the features and advantages of each type of cement.

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