Fiber for floor screed: features of use

Fiber for floor screed: features of use

A reliable, flat and warm floor is not only everyone’s dream of comfort and coziness, but also the stringent requirements of building rules and regulations. Modern technologies make it possible to make such a dream come true and get a high-quality result without flaws. Even a non-professional can assemble a correct and durable floor today. One of the important stages of work on the arrangement of the floor is the pouring of the screed..


According to the technology, the screed must be reinforced. Concrete, in addition to its strength, also has fragility, which must be compensated for. For different types of screeds, there are different types of reinforcing materials and methods, They can be used separately, or can be used in combination. Fiber is one of the most advanced materials..

Fiber elements are made from metal, basalt, polypropylene and fiberglass. Fiber is used not only for reinforcing screeds. It is also added to plaster, mixed into mixtures for road surfaces, used when pouring foundations, piles. The fibers are distributed evenly throughout the entire volume of the solution, and create multidirectional reinforcement. A single structure is formed.

Thanks to this, the characteristics of the concrete layer are significantly improved:

  • Reduces the setting time of the mixture.
  • Strength increased by 90%.
  • Longer service life.
  • Increases resistance to mechanical stress.
  • Decreases moisture absorption.
  • Improves the plasticity of concrete, its viscosity, the ability to suppress vibrations. This allows the use of fiber reinforcement in the military and heavy industry..
  • Resistance to temperature fluctuations, frost resistance.
  • Abrasion resistance is increased. It is important for use in dams, reservoirs, dams.
  • Reduces the risk of cracking and delamination.

Fiber elements of all types are compatible with all additives and components of pouring mixtures.


Metallic fibers are made in a variety of ways. It can be made of stainless steel sheets. The length of the steel elements is 20-50 mm. Wire sections of various shapes are covered with a layer of brass on top. They are usually wave, in the form of anchor and grooved elements. The wire is made from low-carbon steel, length – 50-60 mm, diameter – 1 mm. Steel fiber is used:

  • in industrial and loaded floors;
  • hanging panels;
  • piles;
  • basements;
  • shopping centers and places of high traffic.

In addition, this material is used for pouring foundations, prefabricated structures, monolithic street and supporting concrete structures. There are special bends at its ends, which contributes to a more reliable adhesion to the screed layer. Basalt fiber has excellent shock resistance. This material is effectively used for floors on which an increased load is planned.. The main advantages are:

  • Fire safety of the material, environmental friendliness, neutrality to various chemical environments.
  • When mixed into the solution, the fibers adhere completely to it.
  • Basalt fiber is used for the construction of heat-resistant concrete structures.

For 1 sq. m of concrete is consumed from 1.5 kg of fibers, the consumption of cement and water is reduced when using basalt fiber by 15-20%. Polypropylene fiber is made from synthetic material. The fibers are soft and flexible, light, white, 18 mm long, 20 microns in diameter. Polypropylene fiber is non-conductive. For better adhesion to the structure of the solution, it is impregnated with a special oil substance..

Fiberglass fiber is very resilient and elastic, therefore it is recommended for finishing facades of buildings, concrete products of complex shapes, as well as products for decoration and decoration, garden sculptures, arches. This material reduces water consumption when preparing a mixture by 20%..

Advantages and disadvantages

This wonderful material has no obvious flaws. For the price, fiber reinforcement is quite affordable. A low-quality cheap fake during operation will emit toxic substances, harm the well-being of the owners. At all stages of floor formation, fiber reinforcement helps prevent deformations, protects the screed from cracks. Immediately after pouring, the fibers retain the shape of the screed, are evenly distributed throughout the entire volume.

When the drying concrete shrinks, the reinforcement withstands the load. As it hardens and finally dries, the fiber reduces the stress in the cement layer.

Using fiber, it is possible to reduce the moisture absorption in the screed by reducing micropores and microcracks, improve the adhesion of the solution to the base, thereby facilitating the leveling and accelerating drying. The frost resistance of fiber-reinforced concrete allows it to be successfully used in the northern regions. Steel fiber elements are the most durable, at the same time they have significant weight.

Of course, under very high loads or harsh operating conditions, fiber reinforcement alone, even steel, may not be enough. To solve such problems, complex reinforcement with fiber and reinforcing mesh is used..

Blends of the best quality and required properties are obtained if all ingredients are correctly and thoroughly mixed.. It is necessary to mix the fiber elements with the dry components of the future solution, gradually adding them to distribute the fibers without forming lumps, then add water and a plasticizer.

How to choose?

With such a variety of reinforcing additives, the problem arises of the correct choice of material for each specific case. The choice depends on several factors: the type of structure, the area of ​​the room, its purpose, the thickness of the fiber layer screed, the operating conditions, the planned loads. It is important that the fiber was purchased in a safe place, that all accompanying documents, certificates of conformity, instructions were available, so that it was manufactured at the factory:

  • For “warm floors” in apartments and a standard home leveling coating, the most rational is the use of polypropylene fiber. It is a lightweight material that does not add to the overall weight of the screed, does not conduct electricity and does not create electromagnetic fields..
  • For monolithic reinforced concrete structures with heavy equipment on the floor, severe loads and mechanical stress, steel anchor fiber is the best solution..
  • Fiberglass is recommended for garden sculptures and arches, fences and facades. Its elastic structure allows the creation of complex shapes.

The length of the elements also affects the choice of use:

  • for masonry and external cladding, the fiber length must be at least 6 mm.
  • For monolithic structures, the fiber length must be at least 12 mm.
  • For dams, complex buildings and structures, as well as in aggressive conditions, the length of 18 mm is important.
  • For a semi-dry screed and repair measures, a fiber of 18 mm is suitable.

All types of fibers receive excellent reviews from specialists who use these materials in various areas of construction and in different regions of our country..

Thanks to such fibers, it became possible to build both in earthquake-prone regions and in the northern regions, where the temperatures are extremely low in winter. Excellent reviews come from the owners of the apartments, who made quick and inexpensive repairs using fiber. They note the excellent result and durability of the floor, an affordable price and a reduction in the repair time..

How much to add?

With different amounts of added fiber fibers, a solution with different technical characteristics is obtained. The solution consumption is calculated per 1 m2. Cement and sand are mixed in a ratio of 1: 3, then reinforcing materials are added to the resulting dry mixture, and then water is added to obtain a semi-dry consistency of the mixture. The calculation of the consumption of dry material is in grams per 1 m3 of solution. Of course, the greater the weight of the additive, the stronger the screed will turn out, but there are certain norms:

  • If the proportion of fiber is 300 g, then the concrete is easier to lay down, becomes more plastic, fills the cracks.
  • If you add 500-600 g, the strength indicators of the finished layer will significantly increase, and no shrinkage cracks will appear when drying..
  • With the addition of 800-900 g, concrete gains its maximum strength and acquires all the properties of a reinforced layer.
  • Fiberglass fiber is consumed in the amount of 1 kg per 1 m2.
  • Popular polypropylene fiber is sold in 10 kg bags. There is a packing of 18 kg: in a bag – 20 bags of 900 g or 30 bags of 600 g. Such packing is convenient for preparing a solution.

There is no need to weigh the fiber portion each time. The price for 1 kg of fiber, on average, is 250 rubles.

Technology of use

All stages of creating coatings reinforced with fiber are so worked out and verified that getting the right result without defects is available even without contacting professionals, with independent work. To fill the reinforced screed, the following tools and materials are required:

  • cement, sand, water, plasticizer, fiber;
  • damper tape;
  • level: laser or ordinary water;
  • profile for beacons;
  • usually a tape measure, a ruler;
  • drill with a nozzle for mixing the solution;
  • roller for leveling semi-dry screed (if necessary);
  • screwdriver, fastening materials (screws);
  • construction knife, trowel and spatula.

The stages of work are as follows:

  • First you need to prepare the base for the base screed. To do this, you need to remove all debris, dirt and dust, carry out wet cleaning. The surface should be dry and clean. Next, you need to fill up all the cracks and irregularities with putty, walk along the base with a primer for best adhesion.
  • Find the highest point of the future screed, mark with a level a line along all the walls.
  • Install beacons along which the screed surface will be leveled. Lighthouses are made from a profile. They are fixed at the required height with plaster mortar or cement. After alignment, the beacons will be flush with the surface.
  • A special damper tape is glued along the entire perimeter of the room at the bottom of the walls and around the columns and podiums for plumbing, which performs a compensating function when the concrete expands as a result of temperature changes, for example, when the “warm floor” is turned on. Along with fiber, it prevents deformation and cracking of the screed when it dries.

  • Insulating materials are laid, reinforcing mesh if necessary, thermal insulation and a heating circuit of “warm floors” are mounted.
  • A solution is being prepared. For one part of the volume of cement, 3 parts of the volume of clean sand are taken, from 300 to 900 g of fiber. All ingredients are mixed, then water and plasticizer are added to the dry base mix. If the solution is mixed thoroughly, you get a high-quality fiber cement screed..
  • The finished reinforced solution is applied to the prepared surface with a thin layer of 3-5 cm. It should be noted that the semi-dry screed “shrinks” by 1 cm after tamping.
  • The screed is leveled by sliding the rule along the guide beacons, or the semi-dry screed is rolled with a special roller.
  • They are waiting for drying and curing. For this, the finished screed is covered with plastic wrap, moistened once a day with water. Strength gain time – 1 week. Full hardening time is 2-3 weeks.

The screed reinforced with reinforcement is ready. You can start laying the finishing decorative coating.

You will learn more information about fiberglass for floor screed in the next video..

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