Expanded clay floor screed: how to do

Floor screed - The finishing stage, which is done to level the building foundation and improve the indoor microclimate. To perform this structural element, cement-sand mortar is used, but other components are added to the composition to improve the characteristics of the material. One of them is expanded clay. These are burnt, foamed clay granules, which have different dimensions and configurations. Expanded clay improves sound, heat and waterproofing of the room. A screed with this filler can be finished even without work experience.

Expanded clay floor screed

Expanded clay floor screed: pros and cons

The floor screed with expanded clay has its own characteristics in the device technology, advantages and disadvantages. Before choosing such a solution for arranging floors, it is recommended that you familiarize yourself with the technique of applying the composition and the characteristics of the product.

Features and properties of the material

Material Properties:

universality - the product is suitable for use in any room;
moisture resistance;
fire resistance;
resistance to temperature changes;
increased strength.

Advantages and disadvantages

Advantages of the product with expanded clay:

resistance to mechanical stress even with a thin layer of screed, which allows screed with expanded clay in rooms in which the floor is under heavy loads, for example in warehouses;
the ability to raise the floor to a great height in the presence of strong differences in the construction base;
surface leveling;
light weight, which helps to transport the product to any room;
providing heat, hydro and sound insulation;
application in rooms with high humidity and unheated buildings, as the material has moisture resistance, frost resistance and resistance to temperature changes;
accessibility - the product is sold by construction stores;
lack of deformation during flooding;
environmental friendliness;
fire resistance even under the influence of open flame, the material does not emit toxic substances when heated;
resistance to mold and mildew;
protection against rodents;
durability - material properties do not change after a long operational period;
ease of use - you can use the composition without experience in arranging floors;
reasonable cost.

Product disadvantages:

To improve the thermal insulation of the room, a screed with expanded clay, a layer of more than 10 cm, is required.
When performing a dry screed, additional waterproofing of the surface is required, otherwise moisture will accumulate under the material on the building base. As a result, the humidity in the room will increase, which will lead to the formation of mold and fungus on the walls and interior items.

Expanded clay laid under cement mortar

Material Features

Not any expanded clay is suitable for floor screed. The choice of product depends on the conditions of use of the product. It is recommended to focus on the humidity of the room, the degree of unevenness of the building base and the method of laying the composition.

It is not recommended to purchase material from an unverified manufacturer. Some do not adhere to GOST in the manufacture of the product.In this case, the product may have an increased background radiation, which is dangerous to human health.

The average size of the fractions of the material

Expanded clay screed technology

When performing screed, it is important to adhere to the rules for arranging floors. Only in this case the result of the work will be positive.

Preparatory work

Before starting work, it is recommended to prepare materials and tools:

an industrial mixer or other solution mixing tool;
set of spatulas;
a clean container for preparing the solution;
rule
guides for the rule;
needle roller;
laser level;
rollers and brushes;
ruler and marker.

Set of tools

Floor preparation

Before applying the material, the construction base should be carefully prepared:

Remove the old coating and free the base from the screed. This is done with a crowbar or hammer drill.
Further, the base is freed from dust and other contaminants. To do this, use an industrial mixer or a simple broom.
Close up defects. Slots and potholes are treated with a primer. Then the defects are sealed with cement-sand mortar or sealant. Work continues after solidification of the material.
The surface is freed from greasy and oily stains. To do this, it is recommended to use White Spirit or a solvent.
On a building base primer. It is recommended to do double processing with a break for drying.
Determine the height of the upper layer of the screed. To do this, use the laser level. Usually the height of the screed is 15 cm from the surface.

Screed base preparation

Waterproofing

To protect the building base from moisture accumulation, waterproof the surface. There are several ways to equip the protective layer:

For private houses, it is recommended to use roofing material as a waterproofing material. The floor is treated with mastic to increase the adhesion of the surface and roofing material. Then lay the product around the perimeter of the building base. The material is overlapped with an overlap on the wall. Ruberoid seams are also treated with mastic.
For apartments, it is recommended to use a film as a waterproofing layer. To fix the material using construction tape. The material is laid around the perimeter of the building base with an overlap and with an overlap on the walls.
For rooms of any type, waterproof coating is suitable. Such material is a dry mix for preparing a solution. The product is applied around the perimeter of the building base and several centimeters are laid on the walls. The preparation rules, layer thickness and pour time are indicated on the packaging. Only after drying fill in a coupler.

Waterproofing film for floor screed

Thermal insulation

To insulate the floor with expanded clay, several methods are used:

Filling expanded clay on the waterproofing layer under the screed. The layer thickness is 15-20 cm. After laying the material, the surface is reinforced with a metal mesh. A cement-sand mortar is poured onto the grate and the material is leveled. For this layer of insulation, any type of expanded clay is suitable.
Expanded clay filling under gypsum-fiber sheets. The material in this case is used in the form of sand. The product is placed on a waterproofing layer. Gypsum sheets are fixed from above.
Expanded clay filling between the lag of the floor. A waterproofing shelf is fixed on top of the product and a coating is laid in the form of plywood, boards and other similar material.

There are other ways of warming the building base with expanded clay, but the options listed are the most popular.

Laying material for thermal insulation

Soundproofing

Expanded clay also provides soundproofing of the room. In this case, the material is laid in the same way as in the case of thermal insulation. The product is fixed on the waterproofing layer in various ways.For soundproofing the room, it is recommended to choose high-density material. Only such a product absorbs noise.

Layers of floor screed with expanded clay

Beacon Installation

Lighthouses are fixed as follows:

To fix the profiles, define a fill line. To do this, measure the height of 1.4-1.6 m on the wall and put a mark. This is the beginning of the horizon or zero line.
From the zero line measure the distance to the floor in different parts of the room. All results must be recorded.
Choose the smallest value. This will be a high section.
The screed lines are determined directly. A small size is reduced by another 7 cm. This is the standard size of the screed with expanded clay. On this value outlines the lines along which the guides are set.
First, profiles are installed on both sides of the building base. To do this, indent 10-15 cm from the wall. Outline two parallel lines and then mark out along the perimeter of the floor. The distance between the lines should be less than the length of the rule.
Beacons are fixed. Since a waterproofing layer was installed, it is recommended that the guides be fixed to the cement mortar. To do this, along the marking line at equal distance from each other, tubercles are formed from the material. On such sites fix lighthousesby pushing the product into the solution.
Top hold rule. This allows you to align the guides.

Beacon Installation

Damper tape

Damper tape - a material that is fixed along the perimeter of the wall on the waterproofing layer. Such a product prevents the penetration of moisture on the construction base. The tape improves the waterproofing of any material. The material is fixed 1 cm above the thickness of the screed. If the width of the tape is not enough for the size of the layer, then make two rows and more.

Damper tape

Types of backfill

The following types of backfill are distinguished:

expanded clay gravel - the size of the fractions is 20-40 mm;
expanded clay crushed stone - obtained by crushing granules of large dimensions, the size of such a product is 10-20 mm;
expanded clay sand - the size of fractions is up to 10 mm, such a product is obtained from material residues after processing granules into gravel and crushed stone.

Expanded clay gravel and crushed stone are usually used for screed.

Expanded clay gravel

Ways to fill

There are several ways to fill the floor with screed with expanded clay.

Semi-dry screed with expanded clay

Such an element of the floor construction helps to level the building foundation even in the presence of strong differences. Semi-dry screed with expanded clay also serves as a surface insulation. For this, granules with a size of more than 20 mm are used. The layer thickness of the material is 10 cm and above. The screed is made as follows:

The surface is covered with waterproofing material.
Fix the guides.
Expanded clay is poured onto the surface, the material is leveled with the rule, while ramming the product.
The granules are poured with the so-called cement milk so that the product is firmly fixed and does not penetrate the upper layer of the solution.
A cement-sand compound or other similar product is poured over the expanded clay.
The solution is leveled and suspended until the product solidifies.

For the convenience of pouring screed over expanded clay, you can install a reinforcing metal grill. This will increase the strength of the material.

Semi-dry screed with expanded clay

Expanded clay

This is a wet floor screed method. This method helps to get rid of defects in the building base and curvature, as well as save the solution.

To prepare such a product, expanded clay granules are mixed with a solution of concrete and sand. Expanded clay is previously recommended to moisten with water.
An industrial mixer is recommended for mixing the product. This will help to obtain a solution of a uniform consistency.
Before filling the screed, it is recommended to install profiles and a metal reinforcing grill.
The solution is spread over the surface and the composition is leveled.
The profiles are dismantled, the resulting voids are filled with materials. The surface is re-aligned using the rule.
On top of the screed, fill the material with cement mortar or product for bulk floor. Such a composition is placed on expanded clay concrete, without waiting for the product to dry.
The composition is leveled, waiting for the solidification of the product and lay the coating.

Expanded clay

Dry floor screed with expanded clay

For this method of screed, expanded clay is used, the granules of which are small or medium in size. Professionals recommend using mixed material of different sizes. Technique of performing dry screed with expanded clay:

A waterproofing layer is fixed to the building base.
Set the guides.
Expanded clay is laid.
Drywall is fixed, which has moisture resistance. After that, the topcoat is immediately laid.

Dry floor screed with expanded clay

Reviews

Professionals leave mostly positive reviews about screed with expanded clay. Masters say that an additional layer or additive in a concrete solution increases the heat and sound insulation of the room. Finishers note that the material is easy to stack, so even an amateur can cope with the work.

Professionals also prefer dry screed. Since this method of filling the floor creates a smooth surface that is resistant to mechanical damage. Dry screed also improves the thermal insulation of the room.

Judging by the reviews, wet screed is also no less popular. The ease of preparation and use of the solution is noted.

Some masters prefer a semi-dry screed method. Professionals note that it is more convenient to finish the floor in this way together. One master puts expanded clay, and the other kneads the solution, which is then distributed over the surface.

Aligning Material with a Rule

Good examples and options

A successful version of the screed with expanded clay - preliminary reinforcement surface. This helps to increase the strength of the base and evenly fill the solution.

Another good example is a dry screed. This is the easiest finish. This is especially true for laymen. An amateur will easily prepare a building foundation, lay on his own claydite and sheets of drywall. The disadvantage of such a screed is low resistance to mechanical stress. To increase strength, it is recommended to lay drywall sheets in two layers.

Video

The video in this article demonstrates how to do the screed with expanded clay yourself.

Expanded clay screed is a good solution for improving the indoor microclimate and creating an even and reliable foundation for laying the finish flooring.