Concrete for floor screed in a garage – requirements, choice of brand and class, proportions and preparation

Choosing the appropriate concrete is essential if you’re going to install a floor screed in your garage. Your garage floor’s functionality and durability may be impacted by the type of concrete you select. It must be resilient to temperature fluctuations, moisture, and heavy loads from cars.

There are several brands and classes of concrete, and each is appropriate for a particular use. A blend that strikes a balance between strength and flexibility is ideal for a garage. This gives the floor a smooth, level surface and guarantees that it can support the weight of cars without cracking.

Comprehending the appropriate ratios of cement, sand, and aggregates is imperative in the creation of a superior screed. The proper combination will create a solid base and guarantee that your garage floor looks fantastic for many years to come. Knowing these facts will enable you to make well-informed decisions, regardless of whether you choose to handle it yourself or hire an expert.

To get the best results, preparation is also essential. To guarantee a long-lasting garage floor, it’s essential to properly prepare the base, mix the concrete precisely, and give it enough time to cure. You can build a sturdy, long-lasting surface that satisfies all of your needs with a little knowledge and work.

Aspect Details
Requirements Durable, withstands heavy loads, resistant to chemicals
Choice of Brand Look for reputable brands known for quality
Class Use at least C25/30 for strength and durability
Proportions Standard mix: 1 part cement, 2 parts sand, 4 parts aggregate
Preparation Mix thoroughly with water until smooth consistency
Tips Ensure proper curing to avoid cracks

What does the concept of concrete mortar for screed mean??

A dependable, high-strength coating that satisfies all design and operational requirements is created in a garage box using concrete mortar for garage floor screed, a plastic building material.

Large and small aggregates, plasticizers, and binding agents are added to the garage floor solution, and the proper amounts of water cause a chemical reaction that leads to subsequent hardening.

The most common material used to make garage floor screed is cement binder, which hardens in a humid environment. Epoxy resins, methyl acrylate, and other chemical polymer components are also added to the material to improve adhesion and its mechanical and physical qualities.

Regulatory documents and GOSTs

A garage screed made of concrete is a responsible structure, and the specifications for it are governed by various regulatory documents that are currently in effect in our nation:

  • SP 113.13330.2016. Car parking.
  • GOST 31489-2012. Garage equipment. Safety requirements and control methods.
  • SP 29.13330.201.1. Floors.
  • SP 71.13330.2017. Insulating and finishing coatings.
  • SP 63.13330.2018. Concrete and reinforced concrete structures.

Every designer creating floor plans for different rooms in the building, including the garage, always includes links to GOSTs in the notes to graphic materials.

After the work is finished, the documentation is reviewed and a conclusion is reached. Once the project is put into action, the investor is given assurances regarding the longevity of the garage floor.

What material characteristics do you need to know??

In order to lay a screed in the garage, the following operational and technical supplies must be considered:

  • The grade of cement on which the final strength of the mixture depends.
  • Water-cement ratio and the total amount of water in the solution, which affects the mobility of the raw material.
  • The fraction of fine aggregate – sand, on which the density of the screed depends, as well as its physical and mechanical properties.
  • The presence of coarse aggregate – crushed stone based on granite, as well as its fraction, which affects the abrasion of the screed.
  • The presence of plasticizers to simplify installation and smoothing of the screed.
  • The total number of additives – epoxy resins and other polymeric materials, on which the durability of the design of the bond strength in the crystal lattice depends.
  • The presence and quantity of water repellents that affect the water resistance of the hardened material.
  • The presence and quantity of anti-frost additives, which affects the life of the screed during the cold season in an unheated garage box.
  • The proportions of each ingredient in the mixture for floor screed, on which all technical characteristics, reliability and durability of the future structure depend.

Buying ready-made factory-made mixtures, which are widely available from various domestic manufacturers, is the best option for installing a high-quality screed.

Here, the best quality, right dosage, and presence of extra impurities that greatly improve the material’s performance characteristics can all be relied upon by the consumer.

Requirements

According to the primary construction material parameters mentioned above, concrete used to create the garage’s floor screed needs to fulfill the following technical requirements:

  • The grade of cement must be at least M300 for warm garage boxes and from M400 for unheated parking spaces.
  • The frost resistance index of the structure must be at least F50 for warm rooms and at least F75–F100 for cold rooms.
  • The water resistance of the material must be at least W4 for closed garages and at least W6 for open garage complexes.
  • The mechanical compressive strength of the screed varies from 30–35 MPa under normal operating conditions and from 40–45 MPa when using a parking space for heavy wheeled equipment.
  • The total thickness of the structure should be from 50 to 150 mm, depending on the composition of the floor pie and the space-planning requirements for the garage.
  • The mobility of the prepared concrete mixture should be at least P2–P3 for ease of smoothing after laying.
  • The amount of cement for a conventional screed is from 20%–25%, for a high -strength structure – from 30%–33%.
  • Recommended sand fraction – from 2 to 4 mm.
  • Recommended fraction of coarse aggregate – crushed stone on granite – from 5 to 15 mm.
  • The average ratio of sand and crushed stone in a floor screed is from 70% x 30% to 50% x 50%.
  • The total ratio of cement, sand and crushed stone, as a rule, varies from 20% x 70% x 10% to 35% x 35% x 30%, but, at the same time, there are cement-sand screeds without coarse aggregates with a ratio of 1/ 3 cement and 2/3 sand.
  • The amount of polymer and antifreeze additives should not exceed 5%.
  • The total amount of water depends on the plasticity of the mixture, is determined for each case individually and ranges from 70 to 150 liters for every 1 m 3 of the finished mixture.
  • The average setting period of the material is from 1.5 to 2.5 hours.
  • Depending on the composition of the finished mixture, you can move on the set screed no earlier than after 48–72 hours.
  • The average period for gaining 100% strength is from 15 to 25 days.

In order to attain these markers, which ensure the long-term functionality of concrete for garage floor screed, it is advised to exclusively buy certified components from reliable suppliers with a quality passport. This enables you to compute all required mixture proportions in advance and precisely identify all future design parameters.

How to fill: tips for choosing the right one

The following advice from specialists and qualified decorators should be used when selecting the preferred brand and class of concrete, or cement-sand mixture for screed, for the garage floor’s final coating:

  1. Concrete class:
  2. For closed heated boxes, concrete with class B15 or cement-sand mortar grade M300 is sufficient.
  3. For open unheated parking lots, it is recommended to use concrete class B20 and higher.
  4. In the case of installing a screed in a garage for heavy trucks, or when combining garage boxes with a workshop, concrete with a class of B25 or more should be used.
  5. Frost resistance grade:
  6. For a warm garage, frost resistance grade F50 is sufficient, since in such rooms there are no significant temperature changes throughout the year.
  7. For closed, but not heated garage boxes, a concrete grade of frost resistance of at least F75 should be used.
  8. For open parking lots and garages, this indicator should be from F100 above.
  9. Waterproof grade:
  10. Warm garages are more exposed to the aggressive effects of water when snow melts from car wheels in winter, which is why it is recommended to prepare a concrete mixture with a water resistance grade of at least W6.
  11. For cold boxes with increased frost resistance, a waterproof grade of concrete W4 is sufficient, but experts also recommend preparing the composition with a small margin, up to W6.
  12. Mixture mobility:
  13. When installing a simple screed, on top of which a self-leveling coating is poured or the floor is subsequently covered with porcelain tiles, a minimum amount of water is sufficient to ensure mobility of P2.
  14. If the screed is prepared with the aim of subsequent firmness or grinding and will be operated as a finish coating, mobility should be increased to P3.

If the characteristics are not sufficient, the screed will soon wear out and become unusable. When the indicators are exceeded, the garage owner will incur unwarranted expenses that may exceed the estimate and become the basis for claims from the investor to the contractor.

Here, you can discover even more details about what makes a screed solution, including all of its features.

Why is it important to choose the right components?

It is a responsible process to select the required ingredients and their fundamental mechanical properties when mixing concrete, or cement-sand screed, for garage flooring. This makes choosing the required parts crucial for the following reasons:

  • Achieving the required mechanical strength of concrete.
  • Providing impact or ductile strength from impact impacts.
  • Ensuring the required porosity coefficient, which also determines the water resistance and frost resistance of the structure.
  • Creating a reliable foundation for finishing the garage floor.
  • Reducing the risk of shrinkage cracks, chips, cavities and gouges, both during the period when the material gains strength and during its operation.
  • Ease of laying the concrete mixture, as well as its smoothing and finishing.
  • The amount of plasticizers and other effective additives also determines such an important indicator as the chemical resistance of concrete, which is especially relevant if the garage is combined with an auto repair shop, which involves periodic spills of fuels and lubricants on the floor.

It should be mentioned that the proportions of concrete can vary nonlinearly based on the properties of each component, so in order to get the best results, a careful examination of the recipe and technological map is necessary.

What ingredients are needed for pouring?

The primary and supplementary ingredients are used in the proper proportion when making concrete for a garage floor screed. In each particular instance, the dependability and longevity of the structure rely on the caliber, mechanical and physical characteristics, and chemical makeup of these constituents as well as the method of blending them.

These ingredients, along with their primary and operational requirements, are explained in detail below.

Main

Large aggregates, such as crushed stone, are not used in traditional screed concrete because the structure is not intended to support a load and is not subject to the same stringent regulations. Therefore, in order to prepare such screeds for garage floors, the following fundamental elements are utilized:

  1. Cement. Description: a hydraulic binder that is produced in a factory by sintering clinker ingredients under high temperatures. The cement reaction occurs when the bulk substance is wetted with water in the required proportion, followed by waiting for hydration and polymerization of the material. Cement, as a rule, is supplied in bags of 40–50 kg, differs in strength grade from M150 to M500 and the presence of modifying additives that increase performance properties Requirements:
  2. The screed requires a grade of cement not lower than M300.
  3. The cement is allowed to be fresh, since its total shelf life is no more than 6 months, under natural temperature and humidity conditions.
  4. The bulk substance must be of a uniform color; when opening the bag, there should be no signs of the presence of moisture or hard lumps in the cement. If dense inclusions are detected, it is recommended to sift the cement before adding it to the screed.
  5. Sand. Description: coarse quartz-based aggregate, designed to create a reliable crystalline lattice of concrete during cement hardening. Delivered in bags, or without technological packaging, in the back of trucks. Requirements:
  6. Uniformity of composition.
  7. The maximum fraction should not exceed 5 mm.
  8. The degree of humidity of the bulk substance is no more than 15%.
  9. The sand should not contain foreign inclusions of foreign materials and debris, which requires sifting before mixing with cement.
  10. It is recommended to use only quartz washed sand, as it is characterized by uniformity of composition, the best adhesion and increased mechanical strength.
  11. Water. Description: water is added to hydrate the cement and obtain a homogeneous moving mass of the screed before it is laid in the designed position. The amount of water depends on the degree of mobility, which makes it impossible to accurately determine its dosage. When mixing, water is added portionwise until a viscous plastic mass is achieved. Requirements:
  12. The water temperature must be at least + 10 – +12 oC.
  13. The water must be clean and free from rust or other traces of contamination.
  14. The water should not contain acidic or alkaline components, which is why it is recommended to use liquid only from household water supply.

To achieve the desired effect, it is advised to either replace the material or clean it of impurities first if any of the specified components do not meet the above requirements.

If this guideline is broken, the screed will deteriorate physically quickly and need to be restored two to three seasons after it is first used.

Additional

Professional finishing agents add a few more ingredients to the floor screed mixture in addition to the primary ingredients:

  • Epoxy resins – are required if it is necessary to provide elastic elastic connections between the filler and the binder, if it is not planned to install a final coating on the structure. Smole data should be resistant to destruction under the influence of ultraviolet radiation and a humid environment, as well as when a temperature drops below 0 OS for the entire period of operation.
  • Modifying additives – change the chemical composition of the mixture, which allows it to be stored longer in a plastic state, since they push the moment of setting the substance. These components are necessary when transporting the finished composition over long distances, or when the screed in a garage with an area of ​​more than 100-150 m 2, which requires more time to smoot it to smooth and vibrating. Modifier additives should be distinguished by an environmentally friendly composition, as well as the presence of compatible components with cement and other mixtures for screed.
  • Antorozoic additives – from the name it is clear that these components, which are supplied in both liquid and bulk form, provide increased resistance of liquid concrete to extremely low temperatures. These rooms must accurately correspond to the temperature regime in the room at the time of the screed device.
  • Hydrophobizers – special polymer additives, when kneading which, an impenetrable elastic film is formed on the surface of freshly laid concrete, which prevents moisture that prevents the penetration of moisture during the operation of the screed. These components are necessary in the absence of a ramp for water flow, as well as in cases where the owner does not involve the device of the finishing coating of porcelain tiles.

The state of the environment, the seasonality of the work, the operational requirements for screed, the availability of finishing flooring, and other indicators that are documented in the working project all influence the necessity and quantity of additional components. Generally speaking, the total amount of these additives does not go above 5%.

Proportions

You must carefully adhere to all the instructions on the process chart and the recipe for combining the primary and auxiliary ingredients in the proper amounts when creating your own concrete mix for a garage floor screed:

  • Cement for sand concrete is added in amounts from 25% to 33%.
  • Cement for screed concrete, which contains coarse aggregate, does not exceed 25% by mass fraction.
  • Sand, used as fine aggregate, is the main ingredient of the screed. The amount of this component ranges from 65% to 75%.
  • If there is a coarse aggregate in the concrete screed – granite crushed stone with a fraction of 5-15 mm, the amount of sand is reduced to 50 – 60%, which is replaced by crushed stone with a mass fraction of up to 15% – 25%.
  • Plasticizers, modifying and antifreeze additives, special polymer ingredients that are added to the mixture to change its physical and mechanical characteristics. The amount of these components, as a rule, does not exceed 5%.
  • The amount of water depends on the expected mobility of the mixture. For mobility P2, 1 m 3 requires from 90 to 100 l, and for mobility P3 – from 110 to 130 l.

Therefore, the following quantities of main and auxiliary ingredients are needed when mixing concrete to screed the floor of a heated garage with standard modular dimensions of 6 by 3 m and a thickness of 100 mm:

  1. The area of ​​this room is S = 6×3 = 18 m2 .
  2. The volume of the screed in the room is V = 18 × 0.1 = 1.8 m 3 .
  3. The composition of the sand concrete mixture for screed, according to regulatory requirements, is:
  4. Cement M300 = 28% = 1.8×0.28 = 0.5 m 3 .
  5. Medium coarse quartz sand, humidity 15% = 1.8×0.67 = 1.2 m 3 .
  6. Anti-frost additives – 1% = 0.02 m 3 .
  7. Epoxy resins – 2% = 0.04 m 3 .
  8. Plasticizers – 2% = 0.04 m 3 .
  9. The required mobility for such a simple screed is P2, and therefore it is recommended to add water based on the calculation of 110 l/m 3 of the mixture, that is, for 1.8 m 3, 1.8 × 110 = 200 l of water will be required.
  10. Plasticizers and antifreeze additives are usually supplied in cans. Considering that the density of water-based liquid compositions is approximately 1000 kg/m 3, to prepare 1 m 3 of high-strength garage screed, 20, 40, 40 liters of additional additives will be required, respectively.
  11. Cement is sold in bags of 40–50 kg, and its density is about 1600 kg/m3 . That is, with a required volume of cement of 0.5 m 3, which leaves about 800 kg, 16 bags of M300 Portland cement will be required.
  12. At the final stage, taking into account that some of the materials may remain in the bag, some may spill out or deteriorate, it is recommended to take a safety factor of 7% to 10%, which will ensure almost completely waste-free production of garage screeds with the specified volumetric and planning parameters.

It is necessary to add more water to the mixture in order to increase its mobility. This will result in more intense hydration and a larger cone settlement for the cement-sand mixture, which suggests that self-leveling may occur.

You can find more information here about the preparation and ratios for screed mortar.

Understanding the unique needs for concrete, such as choosing the appropriate brand and class and proportions, is essential to creating a long-lasting and useful floor screed for a garage. Selecting a concrete mix that can tolerate temperature changes, withstand vehicle weight, and prevent chemical and oil spills is crucial. To guarantee a durable and resilient garage floor, this article will walk you through the process of choosing the right materials, stress the significance of the concrete class and brand, and provide you a simple recipe for mixing and prepping your screed.

Tools and accessories

It is advised that a garage complex owner order a ready-made mixture from a concrete mixing unit ahead of time if they need to lay concrete screed over a sizable area. This ensures that at least 10 m 3 of material will be prepared at one time and that the recipe will be precisely followed because electronic dosage systems are used for the ingredients.

A craftsman or property owner will require the following basic tools and equipment to make a mixture for screeding a small garage by hand:

  1. For dosage of ingredients:
  2. Container with a reference volume – preferably a 10 liter bucket.
  3. Electronic or mechanical scales with a division value of no more than 100 g.
  4. A shovel or a special scoop for opening bags and pouring material.
  5. For mixing dry ingredients:
  6. Electric or gasoline mixer with a capacity of at least 150 liters.
  7. Broom and dustpan for collecting spilled material on the floor.
  8. Steel sheet to reduce the risk of spilled ingredients mixing with soil or dust.
  9. For adding liquid ingredients:
  10. Scoop container with measuring scale, volume from 2 to 5 l.
  11. Tap water supply hose.
  12. If necessary, a flow-through heater to increase the water temperature.
  13. If the water is dirty – a funnel with a mesh filter for coarse cleaning of the composition.
  14. At the final stage, you will need a one-wheeled wheelbarrow or stretcher that helps transport the finished mixture to the place where it is laid.
  15. If the temperature in the garage is below 0 ° C, it is also recommended to provide space heating, which allows the cement to accelerate hydration. For such purposes, a diesel, electric or gas heat gun is used.

Every electrical appliance and tool must be of the highest caliber, ideally from renowned manufacturers. To ensure that the desired outcome is achieved, the equipment must also be in good operating order, free of dust and debris, and ready for use.

Step-by-step cooking instructions

The following technology map is necessary for self-preparing concrete or a cement-sand mixture for garage floor screed:

  1. The mixer is cleaned of any old traces of dirt.
  2. According to the recipe, several bags of cement are opened, after which they are poured into a mixer container.
  3. Sand is also added to the mixer tank, which is slowly mixed with cement.
  4. When the mixture reaches a homogeneous structure and a gray color, without contrasting shades, water is added at a rate of no more than 2-3 liters for every 30 seconds of mixing the dry mixture.
  5. Water is added until the mixture reaches the expected consistency, according to the process chart
  6. When the concrete is completely mixed, all modifying and anti-freeze additives are added to the mixer.
  7. The device mixes the finished mixture for another 5-7 minutes.
  8. If the composition turns out to be too thick, it is recommended to add a small amount of water. If the opposite effect occurs, dry ingredients should be added in different proportions (for example, 1 shovel of cement and 2 shovels of sand).
  9. The finished mixture is poured into a stretcher or wheelbarrow, after which it is distributed over the entire plane of the installation horizon.

As you get ready to prepare concrete for screed in a garage box, make sure you precisely calculate how much liquid raw material you’ll need by measuring the mixer’s actual capacity.

For instance, each calculated indicator for the batch given above is multiplied by a factor of 0.12 if the device’s receiving tank has a capacity of 120 liters.

Possible difficulties and errors

The owner of the property or a professional craftsman may run into a number of issues when creating a cement-sand mortar with plasticizers or fine-grained concrete for a garage screed that necessitate the quick adoption of specific measures in order to achieve the desired outcome without lowering operational parameters:

  • Selection of low-quality ingredients – it is recommended to buy cement, sand and plasticizers only from trusted sellers, ask for a certificate of conformity for each batch of goods sold.
  • Purchasing expired cement, polymerization and hardening of which begins already in the factory container – it should be taken into account that the life expectancy of the dry substance, as a rule, does not exceed 6 months, and only fresh hydraulic binders should be purchased.
  • Violation of proportions when mixing dry substances – the screed does not gain the required strength, which entails a decrease in performance and durability.
  • Not enough or too much water – in the first case, the mixture will be too hard, which makes it much more difficult to lay, as well as vibrate and compact. In the second case, the moving liquid composition undergoes large shrinkage as the input rises to the top, after which it evaporates, and the solid substance no longer corresponds to the design mark.
  • Insufficiently uniform mixing of the composition – there is a risk that not all aggregate particles will be filled with liquid cement, which will lead to delamination of the material due to insufficient adhesion.

Before buying supplies and getting to work, it is advised that you familiarize yourself with master classes and video lessons from experts who frequently share their training videos with other users in the public domain on the Internet in order to avoid the challenges and mistakes mentioned above.

Average costs in the Russian Federation for materials

The property owner is responsible for procuring the necessary quantity of materials in order to make a floor screed for a garage.

Because there is intense competition among the numerous trading companies that supply these components, the average price for them is fairly similar.

Based on 1 m 3 of the completed mixture, the following is an approximation of the cost of all the primary and auxiliary ingredients for floor screed in a garage complex:

  • Cement grade M300 – 450–650 rubles. for 50 kg.
  • Cement grade M400 – 600–850 rub. for 50 kg.
  • Cement grade M500 – 900–1100 rub. for 50 kg.
  • Medium-sized quartz sand – from 2500–2800 rubles. per 1 m 3 .
  • Washed quartz sand, fine – from 3000–3500 rubles. per 1 m 3 .
  • Fine crushed stone, on granite, fraction 5–15 – from 5500–6500 rubles. per 1 m 3 .
  • Plasticizer for screed – 350–450 rubles. for 10 l.
  • Anti-frost additive – 400–500 rub. for 10 l.
  • Modifying additive – 350–500 rub. for 10 l.
  • Epoxy resin for concrete mix – 250–350 rubles. for 5 l.
  • Methyl acrylate for concrete mortar for screed in garage – 50–150 rubles. for 1 l.
  • Water repellent for concrete for application after screed hardening – from 4500–6500 rubles. for 20 l. (consumption about 4–5 l per 1 m2 of surface).

The cost mentioned above may differ slightly based on the supplier’s internal marketing policy, the materials’ delivery shoulder, whether or not they need to be lifted to a high floor, the goods’ seasonality, and the area in which they are sold.

Useful video

How-to video for making the perfect concrete:

It is important to take the particular needs of the space into account when selecting concrete for a garage floor screed. Strength and durability are essential considering the heavy load and possible chemical exposure. Selecting the proper concrete class and brand will guarantee long-lasting performance.

Choose a concrete mix that is appropriate for your needs; usually, this is a higher grade, such as M300 or M350, which provides the strength required for garage use. To create a mixture that is both sturdy and workable, pay close attention to the ratios of cement, sand, and gravel.

It’s important to mix and prepare correctly. To prevent weak spots, use an equal proportion of ingredients and make sure they are well mixed. Finish the surface to reduce dust accumulation and improve wear resistance, and think about adding additives for additional resilience.

Your garage floor screed will provide a sturdy and dependable foundation that is able to endure the rigors of regular use if the proper materials are chosen and executed with care.

Video on the topic

How to mix the right concrete. Do you need a plasticizer.

My method and proportions for mixing concrete with your own hands brand M300

HOW TO MAKE THE RIGHT CONCRETE

What factor is most important for you when choosing materials for building a house??
Share to friends
Milan Yashina

Design engineer, specialist in development of design documentation. I will help you correctly design your home or other building.

Rate author
StroyArsenal62.com
Add a comment