Underfloor insulation with expanded clay. Expanded clay insulation: simple, effective and inexpensive. Backfill on the ground between the logs

Wooden construction is mainly country houses. Moreover, both new buildings and those that were built long ago as summer cottages. Today these buildings are increasingly used for year-round living. Therefore, the issue of insulating all parts of the house becomes urgent.

The floor in timber buildings is one of the coldest parts of the entire structure. According to various estimates, up to 20% of the internal heat in rooms is emitted through the floors in wooden houses. It makes sense not only to design good insulation when building a new house, but also to take care of reworking the floor in an already built one, but without. Moreover, usually a residential wooden house is installed on a relatively high foundation. And this allows insulation from below without changing the level of the finished floor and without reducing the height of the room.

Floor insulation

When erecting ancillary wooden buildings, the floors can be located close to the ground or even be laid directly on the ground. In this case, the insulating layer is still necessary, only it will have to be laid, burying it into the ground.

Any insulation of wooden floors must be carried out in compliance with the following rules:

• Compulsory laying of waterproofing in two layers. The bottom layer protects the insulation from moisture from the ground. The top layer - from water penetration through the boards of the finished floor.
• Rough and fine wooden floor elements are treated with special anti-rotting agents.
• For insulation, a material is selected that does not change its properties upon contact with wood.

Despite the recent appearance of modern insulation materials, expanded clay insulation of a wooden floor is still used. And there are reasons for this.

Expanded clay: pros and cons

Insulating expanded clay - granules made by foaming and subsequent clay firing.

Scheme of production of expanded clay granules

It has a number of advantages when used as thermal insulation.

Advantages:

• Low thermal conductivity. The clay itself, from which it is made, is considered a good heat insulator. And the pores created inside, filled with air, further reduce the thermal conductivity. As a heat insulator, it is several times more effective than clay bricks and twice as good as wood.
• Light weight. An increase in the thickness of the expanded clay layer does not lead to a significant load on the floors.
• Cheapness. Despite the fact that it is inferior in thermal conductivity to many modern materials, its use allows you to save money, losing insignificantly in the quality of insulation.
• Fire safety. This material not only does not burn, but even does not emit any toxic substances under strong heating.
• Resistant to temperature extremes. Thermal insulating properties do not change in heat or frost.
• Resistant to household chemicals and moisture. Even when wet, mold does not form on it.
• Complete environmental friendliness. Made from natural material, it is not completely harmless.
• In addition to heat-insulating properties, it is also a good sound insulator.
• Convenient to use. To work with it, you do not need to have special skills, and no special tools and devices are required. The fact that expanded clay is a bulk material excludes any requirements for observing the exact dimensions when laying.
• Long term of use. It is believed to retain its properties for decades.

disadvantages

Expanded clay also has disadvantages. But their list is incomparable with the merits:

• Large volume of heat-insulating layer. To create high-quality thermal insulation, the thickness of the expanded clay cushion should be at least 10 cm.But in practice, the expanded clay layer is usually 20-30 cm, rarely 40 cm.In some wooden floor structures, such insulation leads to a decrease in the space between the floor and the ceiling.
• Low moisture resistance. When a large amount of water gets on it, it absorbs it. This leads to an increase in the weight of the thermal insulation. Over time, moisture will evaporate from expanded clay granules, but this is a long process.
• Laying expanded clay, for all its simplicity, is a tedious task. Filling a thick layer, leveling with the obligatory accuracy, so as not to destroy the shell of the granules - all this takes a lot of time.

Varieties of expanded clay

The quality of expanded clay as a heater also depends on the options for its production. Depending on the size, there are three main groups of expanded clay granules. And although there are recommendations for its use for each group, a mixture of granules of different sizes is usually used in one layer.

Expanded clay fractions

• Crushed stone - granules with a diameter of 20 to 40 mm. Recommended for backfilling the main layer of thermal insulation.
• Gravel - 10 to 20 mm. It is used to create thin layers.
• Sand - the smallest granules with a diameter of 5 - 10 mm. Suitable for insulating small voids in floor structures. Mixed with coarse fractions, it can be used to fill the gaps between the granules. It is used to create a "wet" concrete heat-insulating screed.

In addition to size, expanded clay insulation varies in density. Commercially produced expanded clay is divided into several categories with a density from 200 to 800 kg / m3.

Methods for creating heat-insulating layers of expanded clay

In general, the construction of expanded clay insulation differs little from the use of other materials. Expanded clay is located under the finished floor with the use of moisture-proof materials.

Warming with expanded clay, general principle

Depending on the location of the insulated floor (on logs laid on a foundation, on the ground or on a concrete base), the technology by which expanded clay is laid under a wooden floor also differs.

Backfill between lags

This is the easiest way to lay a claydite cushion. In this case, wooden logs serve as the basis for the floor. If they are on the foundation, then shields or sub-floor boards are attached to them. They can be hammered to the lags from below or attached to bars nailed to the lags on the side. The use of lightweight expanded clay serves as an advantage - the load on the sub-floor is low.

Further actions are as follows:

• The logs themselves and sub-floor boards are recommended to be treated with anti-rotting agents. This is especially necessary when creating new insulation in a long-built house.
• The space between the lags is lined with a waterproofing film. As its substitute, you can choose polyethylene or roofing felt. If transverse bars are installed between the lags, then each cell is covered separately.
• Expanded clay granules are poured into the prepared intervals between the logs. It is recommended to mix coarse and fine fractions of expanded clay to fully fill the volume.
• After backfilling, the expanded clay layer is leveled along the upper edges of the log. The lags act not only as a support, but also as an indicator of the level of the insulation backfill.
• It is advisable to tamp the leveled layer of expanded clay lightly. When tamping, you must not damage the granules, since they will absorb moisture through the cracks.

Expanded clay, covered on a wooden sub-floor along the logs

The installation of the floor along the logs can also be carried out on a concrete base as a sub-floor. In this case, the expanded clay backfill technology is no different.

Backfilling of expanded clay on logs on a concrete base

Backfill of expanded clay for a wooden floor on the ground

Such floors can be installed in utility rooms or garages. But the expanded clay pillow is not laid out directly on the ground. The procedure is as follows:

• The top layer of the earth is removed.
• A layer of gravel is filled up. It will perform the function of waterproofing, protecting expanded clay from moisture from the ground.
• The gravel is covered with sand, which must be carefully tamped.
• A protective film is laid over the sand.
• The insulating layer of expanded clay is poured onto a sand cushion, leveled and lightly rammed.
• Further flooring depends on the wishes of the builder. You can lay the floor directly on top of expanded clay, you can fill the expanded clay layer with concrete, forming a "wet" screed. And you can use a layer of expanded clay as a rough insulation, creating another insulating level above it, on top of which to lay a finishing floor.

Expanded clay bedding as a sub-floor on the ground

Concrete screed using expanded clay

If a concrete base is supposed to be installed under floorboards, then such a floor can be insulated by "embedding" expanded clay into a concrete screed:

• The base prepared for the screed is closed with waterproofing.
• The entire surface is covered with expanded clay. Small fractions are predominantly used.
• The expanded clay layer is leveled and compacted.
• For greater reliability, a reinforcing mesh is placed on top of the expanded clay.
• The last stage is concrete pouring.

Concrete screed on expanded clay pad

Dry expanded clay screed

This method of flooring has recently become known. The preparatory part depends on the base on which it is planned to arrange the screed - on the ground, on a rough wooden floor or on a concrete slab.

The base is covered with a protective film on which expanded clay is poured. After leveling the expanded clay cushion, it is covered with sheets of plywood or gypsum fiber. Fastening sheets - with glue, or with self-tapping screws.

Dry screed with insulation

Final work

Any version of the device of expanded clay warming layer means the completion of the rough stage of flooring. The insulating layer must be covered with a hydro or vapor barrier material. And already on top of this insulation made of plywood or other sheet material, a substrate is fixed, corresponding to the selected floor covering.

With the option of a floor on logs, a wooden finishing floor can be installed directly on them, without creating a separate substrate.

Section of a wooden floor with expanded clay insulation

Insulation of the floor, walls, and other parts of a wooden house usually occurs with expanded clay. This is an inexpensive but high quality insulation. True, it is used mainly in wooden houses, its use in brick, aerated concrete is not always advisable (floor insulation with its help can be done there, but walls and ceilings are not). The article will consider the pros and cons of expanded clay as insulation, and also give instructions on how to use it to insulate the floor and ceiling.

Features of the insulation of a wooden house

In order to understand how best to carry out the insulation of a wooden house, it is necessary to identify the qualities inherent in such buildings:

• wooden walls, ceilings, floors have excellent vapor barrier performance;
• have weak resistance to mechanical damage, are not fireproof;
• wooden houses immediately after construction significantly settle (have a high shrinkage coefficient);
• have good thermal insulation qualities.

Based on the specified criteria, you will need to choose a heater. And such insulation as expanded clay is an almost ideal solution for a wooden house. In fact, insulation for a house made of wood should have the following qualities:

Expanded clay is one of the most popular heaters for wooden houses

One of the most important advantages of expanded clay is fire resistance and fire resistance, which is especially important for wooden houses.

Pros and cons of expanded clay as insulation

To begin with, it is worth deciding what kind of material such as expanded clay is in general? It is a building gravelly free-flowing porous material made from shale and clay, fired to give it various properties in special furnaces.

In fact, it is such a powdered shale clay. The material is really very cheap, while in terms of its operational qualities it is not inferior to sawdust, or expanded polystyrene, or other types of insulation used in wooden houses.

Scheme of warming the foundation of a frame house using expanded clay

This type of insulation boasts the following advantages:

• it has complete biological safety (this material is harmless to the human body, insect larvae cannot appear there: it is for this reason that the insulation of the floor with expanded clay, as well as the ceiling and walls is so popular);
• resistant to mechanical damage (for example, it is very difficult to gnaw it for mice and rats, which are often "companions" of a wooden house);
• fire resistant;
• has a low weight (lighter - only foamed polymers such as mineral wool, so that it will practically not give a load on the floors);
• has excellent soundproofing and noise-absorbing properties (due to the porous structure, the insulation has the so-called "thermos" effect);
• simplicity and ease of installation (insulation of a roof with expanded clay or a floor can easily be carried out by one person, and the latter does not need to have any special skills in the field of construction);
• low cost (one of the main advantages of this material);
• does not rot or decompose.

Of course, the described material has its drawbacks:

Moisture absorption is not such a terrible drawback, for example, mineral wool significantly outperforms the described insulation in this indicator.

Expanded clay is not a moisture resistant material - this is one of its main disadvantages.

But here the point is different: the "wet" material will dry for a very long time. Moreover, it will swell and increase significantly in its weight (accordingly, the load on the floors will also increase).

Floor insulation in a wooden house

Warming a wooden floor with expanded clay to carry out, as noted above, is quite simple. There are 2 ways to lay the material:

1. By scattering (the so-called "dry" screed, when the floor is laid directly on the material itself);
2. Under the cement screed.

It is difficult to say which particular way to choose. On the one hand, if the house is frame, panel board, made of SIP panels, then it is not recommended to make a heavy floor there with a screed. By themselves, such houses are very light, their foundations are designed for the lowest possible load.

On the other hand, if the house consists of the same rounded or glued beams, then a cement screed is not only possible there, it is simply desirable there. Expanded clay is laid by scattering when it comes to the so-called "earthen flooring" for the floor.

Scheme of insulating the roof of a house with expanded clay

The soil is carefully compacted, a sand and gravel pillow is made on it, fractions are carefully scattered on this pillow, after which the floor is laid. The only nuance that must be taken into account is that with this method of insulation, the expanded clay layer must be at least 10 centimeters.

More is possible, but less than 10 centimeters is impossible, this is not allowed by either sanitary and hygienic or engineering standards. Under the screed, of course, it is somewhat more difficult to carry out insulation.

You will need the following materials:

The work is carried out in several stages:

1. If an old floor was available in the house, then it is completely removed, the lower surface is protected and, if necessary, leveled out (the difference in surface height can range from 3 to 5 centimeters, but no more);
2. The surface is completely protected from dirt and dust, for which it is processed with a brush with stiff bristles, after which it can be vacuumed (if there is no construction vacuum cleaner, you can also use a regular home vacuum cleaner);
3. If there are defects such as chips and cracks, they can be repaired with tile glue, polyurethane foam or concrete mortar;
4. The next step is waterproofing the floor. It can be done either with the help of waterproofing mastic or, which is much easier, with the help of an elementary dense polyethylene film;
5. Along the perimeter of the floor, to a height of 10 centimeters, an edge tape must be glued to the walls, which will prevent thermal deformation in the future;
6. Beacons are installed as for a conventional cement screed);
7. The first layer of expanded clay is filled up with a dry method;
8. The second layer of expanded clay is mixed with concrete mortar in a ratio of 5: 1, the screed is poured, after which a new, already even layer of screed is applied, without expanded clay.

   
   Table of comparative properties of expanded clay, based on the size of fractions

Waterproofing mastic is one of the best materials for waterproofing floors.

Ceiling insulation

Expanded clay for the floor is no different in composition and size of fractions from the material for the ceiling. Yes, and the insulation of walls with expanded clay can be said the same (however, walls made of expanded clay are quite rare).

Comparison of the physical properties of different materials

So, the insulation of the ceiling is as follows:

Video

You can watch a video where experts talk about how to carry out floor insulation using expanded clay.

For passionate supporters of the use of ecological materials in construction, the question of whether expanded clay can be used for floor insulation will probably seem strange - of course, yes! For its production, absolutely natural materials are used - clay and shale rocks, which are sintered and granulated in a rotary cylindrical kiln at a high temperature. As a result, granules of different sizes are obtained.

• More about expanded clay
• Varieties of expanded clay
• What kind of expanded clay is better for floor insulation?
• Advantages and disadvantages of expanded clay
• Methods of warming with expanded clay
  • Dry insulation with expanded clay
  • Wet laying of expanded clay
  • Combined method
• Warming with expanded clay under a wooden floor on a concrete base
  • Materials and tools
  • Dismantling the cover
  • Surface preparation
  • Waterproofing
  • Installation lag
  • Backfill of expanded clay
  • Installation of flooring
• Warming with expanded clay under a wooden floor on the ground
• Warming with expanded clay under a concrete base
  • Floor preparation
  • Backfill of expanded clay
  • Reinforcement
  • Screed performance
• Expanded clay concrete screed

But expanded clay is good not only for its high environmental friendliness. It should also be noted its low cost in comparison with other insulation materials, as well as the ease and speed of its application, because this does not require any special equipment.

More about expanded clay

The word "expanded clay" has Greek roots and is translated as "burnt clay". This material is extremely light, has a cellular porous structure, and its granules are round in shape. In the process of firing, low-melting clays, to which peat, sawdust and diesel fuel are added, swell. Expanded clay is often used in construction as a filling in concrete in cases where it needs to be made lighter.

The heat-insulating properties of expanded clay are influenced by:

• the size of the granules;
• the strength of the granules;
• density of the material.

According to the bulk density (or volumetric weight), there are 10 brands of expanded clay (from 250 to 800). The brand number hides the bulk weight of the material, expressed in kilograms per cubic meter. For example, a cubic meter of 250 grade expanded clay weighs exactly that much in kilograms.

The greater the porosity of the material, the lower its density and the higher its heat-insulating properties, which is very important when choosing which expanded clay is better for floor insulation.

Different bulk density is obtained with different methods and modes of processing of raw materials. The bulk density is determined by filling in special measuring vessels. Usually the largest fraction has the smallest volumetric weight.

Varieties of expanded clay

Expanded clay sand

It is formed after firing the remains of clay or by crushing large fractions of expanded clay. The particle size here is no more than 5 mm. This sand, together with coarse fractions, is used when insulating interior partitions or when insulating a floor with expanded clay concrete is required. It also serves as a grout filler.

Expanded clay gravel

It represents round grains of 5-40 mm in size with a porous structure, which are obtained in pyrogenic furnaces by swelling of superfusible clay. It is a fireproof, frost-resistant and water-resistant material.

Expanded clay crushed stone

It is angular, has no definite shape, and is similar in size to gravel. It is obtained by crushing large pieces of expanded clay, and is used together with other types to obtain lightweight concrete, if the concrete floor is supposed to be insulated with expanded clay.

What kind of expanded clay is better for floor insulation?

When classifying expanded clay, the size of its granules can be selected as a basis. The division into fractions is as follows:

• Fraction from 5 to 10 mm is used for the manufacture of claydite-concrete blocks and when pouring screeds.
• Granules from 10 to 20 mm are the answer to the question of which fraction of expanded clay is used to insulate floors or ceilings in houses.
• Basements, roofs, garage floors and heating mains are insulated with a fraction of 20 to 40 mm.

If you put the second and third fractions in the screed, then its thickness will increase.

Advantages and disadvantages of expanded clay

Advantages

The pluses of expanded clay include:

• good thermal insulation and sound insulation;
• fire resistance;
• high strength;
• durability;
• frost resistance;
• environmental friendliness.

Warming the floor with expanded clay under the screed can be chosen for a number of reasons:

• Expanded clay is exceptional in that it can be poured on any base, even on the ground, directly on which foam or mineral wool cannot be placed, since they will quickly lose their useful qualities.
• Expanded clay has the greatest strength among other insulation materials.
• The eco-friendly composition ensures safe use of expanded clay, since it does not release anything into the air.
• Due to its incombustibility, expanded clay does not have any restrictions in terms of fire safety, it can even serve as a barrier to an open flame.
• Expanded clay is the cheapest insulation, therefore, for a long time and very widely, insulation of the floor with expanded clay in a private house, as well as walls and ceilings, has been used. In addition to private buildings, it is widely used in industrial and other buildings.

disadvantages

A significant disadvantage of floor insulation with expanded clay is its strong hygroscopicity. When its granules are actively saturated with water, they completely lose their heat-shielding properties, and for a long time they do not give moisture back. Damp, heavy expanded clay begins to sag, and unevenly, which leads to deformation of the floor, which must be taken into account if insulation with expanded clay and screed floors of the 1st floor is carried out. To avoid this, when arranging floors, you need to carry out reliable waterproofing.

Methods of warming with expanded clay

Builders use three methods of adding expanded clay:

• wet;
• dry;
• combined.

To make the technology of warming floors with expanded clay more understandable, you should understand each option in more detail.

Dry insulation with expanded clay

This is how the floor is usually insulated with expanded clay in a wooden house.

1. The material is poured between lighthouses or logs, and a sub-floor made of plywood, chipboard or ordinary boards is mounted above it.
2. To protect the insulation from moisture, it is imperative to lay a waterproofing material under it.

To increase the density of the granules filling, it is recommended to take their different fractions and mix them before filling.

This is a very fast way of warming, which does not require a lot of labor.

Video about the dry method of floor insulation with expanded clay:

Wet laying of expanded clay

Here, a screed is made of expanded clay concrete. Liquid concrete is mixed with expanded clay, after which the volume between the lighthouses is filled with it.

In addition, the screed dries faster and cracks less. But the use of the wet method leads to the fact that the thermal conductivity of the expanded clay that has gained moisture is greatly increased.

Combined method

Warming of a concrete floor with expanded clay under a screed is done as follows:

1. Dry expanded clay is poured between the lighthouses.
2. Then it is leveled.
3. Its uppermost layer is watered with liquid cement mortar.
4. When it dries up, a regular screed is made on top.

The cement mortar forms a crust on the upper layer of expanded clay and does not allow deformation of the lower layers when pouring the screed.

If a large load is expected during the operation of the floor, then the structure can also be supplemented with a reinforcing mesh.

Warming with expanded clay under a wooden floor on a concrete base

Materials and tools

To insulate a wooden floor with expanded clay, you will need:

• jigsaw or hacksaw;
• nail puller;
• pencil;
• roulette;
• hammer;
• building level;
• electric drill;
• shovel;
• self-tapping screws;
• damper tape;
• coating material or film waterproofing;
• sand.

In this example, the insulation of the floor of the first floor with expanded clay on a concrete base is considered.

Dismantling the cover

1. It is necessary to remove the floor boards and take them out of the room.
2. Carefully inspect the logs and check their position with a level.
3. Rotten logs need to be replaced, and new ones should be set according to the level.
4. If the bars are in good condition, not deformed or deflected, then they can be left.
5. If the damage is minor, it is enough to replace individual bars, and if they are rotten or loosened, then you need to remove everything down to the concrete.

Surface preparation

1. Free the base of the floor from debris, rub small cracks and inspect the corners - if there are deep cracks, then they need to be filled with foam or covered with mortar.
2. The joints around the perimeter of the walls and floor should also be filled with foam.
3. Then a layer of sand must be poured onto the base and thoroughly tamped, but if coating waterproofing is used, then there is no need for sand.

Waterproofing

1. A special membrane or plastic wrap must be spread on the floor so that it covers the walls with its surplus by 7-10 cm.
2. In this case, the lags should also be under the film.

When the width of the canvas is not enough, then you can lay several pieces with an overlap, and fix the joints between them with construction tape.

1. Fix the waterproofing on the beams with a stapler, having previously tucked it well in the recesses between the logs

1. If coating waterproofing is used, then the mixture must be applied to concrete, which is free of dust, including sections of the walls near the floor. With this option, the logs should be on top of the protective layer. It can be coated with liquid polymers, bitumen mastic, polymer-cement-based mastics and bitumen-polymer mixtures. The composition should be applied in 2-3 layers at intervals of 3 hours, so such waterproofing will take a long time.

1. At the end, you need to fix a damper tape at the height of the subfloor along the perimeter of the walls, which will resist cracking and deformation of the screed during temperature changes.

Installation lag

1. If the old logs had to be completely dismantled, then new ones must be mounted. For this purpose, a durable wooden beam or boards are suitable, which must be cut to the length of the floor, then soaked with an antiseptic and dried completely.
2. The wooden frame on the floor must be at least 10 cm.
3. The extreme logs should be located 2-3 centimeters from the walls, and the step between adjacent logs should be within 50-100 cm.
4. All logs must be set parallel to each other and at the same level so that their upper surfaces all lie together on the same, strictly horizontal plane.
5. The logs need to be fixed to the floor using metal corners: screw one side of the corner with screws or self-tapping screws to the log, and the other to the floor.
6. The extreme corners should be 2-3 cm from the edges of the log, and the step between adjacent corners should be within 50 cm.

Backfill of expanded clay

Before you form a layer of expanded clay for floor insulation, you need to mix its coarse and small fractions, and then fill it between the logs.

It will remain on top to lay the waterproofing and fix it with a stapler.

Installation of flooring

To the beams protruding from the insulation layer, you need to attach a sub-floor made up of boards, chipboard or plywood, after which you can already lay the topcoat. The film sticking out near the walls can be cut with a knife and the gaps can be closed with decorative skirting boards.

Warming with expanded clay under a wooden floor on the ground

Sometimes, instead of a concrete base, there is soil under the floor, in this case it is required to insulate the floor with expanded clay on the ground in the following sequence:

• Level and compact the ground.
• Pour in about 10 cm of gravel.
• Cover gravel with sand and compact it tightly.
• Next, pour insulation, while the thickness of the expanded clay layer should be 15-25 cm.
• Having leveled the layer of insulation, it is necessary to pour it on top with concrete.
• Wooden floors can be installed.

Warming with expanded clay under a concrete base

Floor preparation

In this case, the standard preparation of the subfloor is performed:

1. It is necessary to dismantle the old coating, fill up all the cracks, clean the surface of dust.
2. After that, lay a film on the base or cover it with liquid waterproofing. To close all joints along the perimeter of the floor, the film must be brought onto the walls.
3. At the end, at the level of the future screed, you need to fix the damper tape, after which you can proceed to insulation.

Backfill of expanded clay

First you need to calculate how much expanded clay is needed for floor insulation. According to the standard for 1 sq. m area you need 0.01 cubic meters. m of expanded clay with a layer thickness of 1 cm.That is, the required amount depends on the thickness of the expected insulation layer and the area of ​​the room.

Expanded clay thickness for floor insulation:

• On the 1st floor and above unheated rooms - 10 cm.
• On the 2nd and higher floors in residential premises - 3-4 cm.

For example:

• In a room with an area of ​​20 sq. m you need 10 cm of insulation thickness (expanded clay).
• With a thickness of 10 cm of expanded clay, it needs 0.1 cubic meters. m per 1 sq. m area.
• For 20 sq. m area will need 0.1 * 20 = 2 cubic meters. m of expanded clay (1 cubic meter of expanded clay = 400 kg).

1. The resulting amount must be prepared by mixing its different fractions.
2. Then you need to fill all the space between the beacons with this mixture, leveling the material with a piece of plywood or a rule.
3. It is especially necessary to fill in the joints and corners so that there are no voids left there.
4. Then the expanded clay must be tamped carefully so as not to damage the granules.

Reinforcement

Put a coarse-mesh metal mesh on top of the insulation, which should be 4-5 cm from the walls everywhere. The mesh should be without sharp protruding edges, bulges or dents.

Screed performance

1. The screed mixture should consist of 1 part of cement and 3 parts of sifted sand, which must be well mixed with water until an even thick consistency is obtained, then pour it in portions between the rails on the floor.
2. The mixture must be leveled with a long rule, passing it along the beacons and removing its excess.

After that, you need to wait until the concrete gains sufficient strength to lay the floor.

This insulation of the floor with expanded clay assumes that the screed is directly, without additional insulation, placed on the insulation.

Video about floor insulation with expanded clay under the screed:

Expanded clay concrete screed

If the subfloor is very uneven or you need to significantly raise the floor level, then this requires an expanded clay concrete screed:

1. At first, the surface also needs to be cleaned of dirt and dust.
2. Then walk the foam along the joints and cracks, put waterproofing.
3. Then you can start the main process.
4. Fix the metal beacons to the floor with cement mortar.

1. After mixing cement and sifted sand in a ratio of 1: 2, add 3-5 parts of expanded clay there (this depends on the expected load on the floor) and 1 part of water.

1. Fill the space between the beacons 2-3 cm below their level with the mixture.

1. The surface should be compacted and leveled, for which the floating granules should be again drowned in the solution.
2. As soon as the screed slightly grabs, prepare ordinary concrete without additives and pour over the screed, then align it with the beacons as a rule.

The screed should dry for 3-4 weeks. In the early days, its surface must be watered so that cracks do not form on it. The result is a warm and solid base that can last for a long time. When it is possible to walk on the surface of the screed, it should be covered with a hydro-barrier or foil.

In what way did you insulate the floor with expanded clay, and why did you choose it? Write the answer in the comments - your experience is important to us.

The main specifics of the expanded clay insulation works, its strengths and weaknesses, floor preparation and thermal insulation technology, the creation of a concrete screed and surface finishing.

The content of the article:

Thermal insulation of the floor with expanded clay is one of the most well-known methods of its thermal insulation. Many synthetic heat insulators, which were in demand earlier, are being replaced by natural heat insulators, which are safer for humans and pets. Considering the relatively low cost of material and consumables, it is not surprising that it has earned such popularity.

Features of thermal insulation of the floor with expanded clay

Expanded clay refers to natural insulation, since it is made from clay and shale-containing rocks, which include no more than 30% quartz in its basis. During the manufacturing process, the raw materials are heat treated in special ovens. Temperature acts on it in such a way that it is sintered and forms granules of various sizes.

During production, it is not possible to achieve the release of granules of the same size. Therefore, expanded clay is subdivided into the following fractions: sand - 5-10 mm, crushed stone - 10-20 mm, gravel - 20-40 mm. The material is lightweight and porous.

Experts recommend it as a reliable and effective heat insulator, since it is not only harmless to the health of the inhabitants, but at the same time reduces the cost of insulation, as well as further maintenance of the building. What kind of expanded clay for floor insulation is better depends on the type of building and its purpose. To achieve the maximum effect of thermal insulation with this material, the features of the floor surface on the first floors of structures are taken into account.

During the calculations, it is necessarily taken into account that this layer of only 10 cm has an effect that is equal to 20 cm from wood insulation. To fill up expanded clay around the perimeter of the insulated floor or to mix with a concrete screed, each owner decides for himself.

If you are interested in how to insulate the floor with expanded clay, pay attention to its main properties in combination with other materials. One of the most common methods of thermal insulation is mixing cement with expanded clay granules. As practice shows, it is this option that improves the insulation characteristics of indoor floors. On the other hand, the main advantage of this material is the presence of air bubbles in it, which are obtained during the production process.

When we insulate the floor with expanded clay with our own hands, mixing granules with a cement-sand mortar, we achieve a deterioration in its thermal insulation qualities due to the presence of water in the composition. That is why professional construction crews in many cases prefer the dry method of insulation. But the use of wet mortars is in demand at those facilities where the floors are characterized by significant differences and it is required to level them with a new concrete screed. In addition, it is much easier to work with solutions than with dry expanded clay.

It's important to know! Granular expanded clay must be laid so that it is reliably isolated from moisture that may enter from below. Even in cases where the heat insulator is not placed directly on the earthen base, you cannot do without covering it with a waterproofing film. The height should be such on both sides that it rises several centimeters above the insulation.

Advantages and disadvantages of floor insulation with expanded clay

The main positive characteristics of this insulator are as follows:

• It is completely harmless to humans and pets, since no chemicals are used in its manufacture, but only exclusively natural materials.
• In addition to heat-insulating qualities, it acts as a good obstacle to the penetration of extraneous noise and sounds into the room.
• Expanded clay is characterized by increased fire resistance and resistance to significant temperature fluctuations.
• It perfectly withstands even the most severe frosts, preventing heat leakage from the building.
• Simple installation technology makes it possible not to involve outside specialists at the stage of such work.
• Expanded clay is practically not subject to physical, biological and chemical influences.
• You can achieve different values ​​of thermal insulation by changing the size of the material fractions.

There are, of course, certain disadvantages that distinguish floor insulation with expanded clay. Firstly, it is a rather high fragility, which it owes to natural raw materials. This can significantly complicate the creation of an insulating layer. Therefore, it is necessary to lay expanded clay with maximum care so as not to disturb the structure of the granules - otherwise it will lead to a violation of the insulating qualities.

Secondly, it is worth mentioning the moisture-absorbing characteristics, which can also be a real drawback. This is due to the fact that the granules only absorb moisture, but do not give it out.

Another negative quality is the thickness of expanded clay. It automatically leads to the creation of a rather thick insulation layer. Consequently, such thermal insulation is not entirely suitable for rooms with low ceilings, because the volume of space will noticeably decrease.

Technology of floor insulation with expanded clay

These works are not particularly difficult if you carefully follow the recommendations given here. This does not require construction qualifications, but the specified algorithm must be followed.

Preparatory work before installing expanded clay

Before proceeding with thermal insulation, it is necessary to carry out a number of works to prepare the floor surface. It may include removing old flooring, old logs, and fixing structures. All this can be left only if the wear of the elements allows them to be reused.

When it comes to insulation on a subgrade, it is first carefully leveled and then compacted. A layer of gravel or crushed stone with a height of about 30 cm is laid on it. A 10-cm layer of sand is poured on top of these materials.

For concrete substrates, it is sufficient to remove the protruding folds with a grinder with concrete attachments. Pits and grooves are sealed with leveling compounds or putty.

After that, the floor is cleaned of debris, particles and dust, and wet cleaning is performed. Once the surface is completely dry, it is covered in 2 layers of primer. The base is ready for insulation.

For country and cottage-type houses, it is best to make a choice in favor of insulation along the logs.

Instructions for installing expanded clay on the floor

As for the fractions of expanded clay for floor insulation, in order to achieve greater efficiency, it is necessary to mix heterogeneous, that is, different sizes of granules. Therefore, large pieces of material alternate with small pieces in the same space. This is also due to the fact that large granules are worse compacted by themselves.

The very essence of floor insulation with expanded clay comes down to the following:

• Before falling asleep on the floor of the granules, it must be waterproofed. Even ordinary plastic wrap can work for these purposes. The joints on the panels are fastened with ordinary tape - this is necessary in order to end up with a single canvas.
• To carry out insulation, it is required to obtain a perfectly flat surface of the site. To achieve its leveling, the level of the future floor is marked with construction beacons before filling. The first is installed at a distance of 2-3 cm from the wall. All subsequent ones are placed in a parallel line, thereby achieving a single screed. You can use cement mortar to fix the beacons.
• After all the guides are aligned, proceed to backfilling expanded clay granules. The layer of insulation should be as even as possible, not contain irregularities and drops.
• In order for expanded clay to be reliably fixed, it is poured with cement mortar. It will give the future layer the necessary strength.
• In some cases, the use of a reinforcing mesh may additionally be required. She will be able to give the whole structure a single whole and reduce the risks of deformation of the insulated coating.

The full hardening period of the poured floor is from 7 to 10 days, after which it will be possible to move freely on it.

Pouring concrete screed

After the expanded clay insulation is laid, it must be closed with a concrete screed. It will not only give strength and fix the top layer, but also provide waterproofing on top.

But first, another intermediate layer is poured. It is made on the basis of a mixture of cement and water, which form a kind of suspension. It should be neither too liquid nor too dry. This layer is necessary for the cement to displace air from the air pores. The result is a monolithic coating that will not be afraid of heavy loads or excessive moisture.

But now you can proceed to the final screed, which will not only level the insulated floor, but also prepare it for laying any kind of floor covering.

The quality and strength of the entire structure as an assembly will depend on the quality of the prepared solution. In other words, it is the quality of sand and cement, as well as their proportional ratio in the mixture. A lack of cement leads to a weakening of strength, while an excess of it leads to an overly rapid solidification of the solution.

The optimal ratio is considered: 1.5 parts of cement per 1 part of sand, while water should not be more than 20% of the obtained volume of dry matter. It is added by eye, and then mixed until a homogeneous solution is obtained, which is poured onto the expanded clay on top.

The coating is leveled evenly over the entire layer of the heat insulator using a large spatula, and as a result, a so-called "tightening mirror" is formed.

The following guidelines will help you to create a correct and effective screed that will perfectly level the floor:

1. It is important to prepare the potting mixture in the correct proportion.
2. Drafts, excess moisture should be eliminated whenever possible.
3. The mixing plant and working containers for solutions should be prepared in advance, as well as ensure the functionality and safety of the equipment.
4. The base level of the floor is measured, after which calculations are made to determine the height of the future screed.
5. The layers must be applied in a sequential order.
6. In order to control cracks, cuts with a spatula can be used if necessary.

The technology of floor insulation with expanded clay, followed by the installation of the screed, requires full drying of the poured surface before final finishing. This allows you to provide the necessary connection of materials. To do this, it must be covered with any protective materials - sheet cardboard, plastic, etc. will do.

Finishing of the insulated floor

One of the promising options for finishing a heat-insulated floor can be the laying of parquet with subsequent varnishing. True, this technology is not affordable for every owner because of the high cost of wood. For parquet flooring, it is necessary to invite experienced craftsmen, as this requires special grinding machines and laying skills.

To give a finished look to the laid parquet, it is scraped. Skirting boards are mounted, the coating is coated with varnish or oil. Parquet scraping with subsequent sanding takes place in several stages using machines equipped with various attachments. For example, rough finishing is used to eliminate the differences between adjacent parquet boards, as well as to remove dirt. After that, sanding is done clean, as well as the processing of hard-to-reach places, in particular under the elements of the heating system, etc.

Lacquered and painted skirting boards are nailed to the walls after giving them their final appearance: wallpapering, painting, paneling. Skirting boards are nailed with special nails, which are driven in and hidden in wooden corks.

The last stage will be the finishing of the parquet. It can be varnished or oiled. This layer not only gives the floor an attractive appearance, it reliably protects it from moisture, household pollution and other influences that lead to accelerated wear of the parquet. Parquet boards cannot be washed without varnish or oil, but after coating, excess dirt and dust can be easily removed from them with a damp cloth.

When working with parquet, it is necessary to use protective equipment such as masks and a respirator, and the doors and windows themselves in the room must be open for high-quality weathering of harmful fumes. Wait time between varnishing operations.

As soon as the first layer is dry, the surface is thoroughly smoothed with sandpaper. The dust must be collected with a vacuum cleaner and dry rags, after which a secondary varnish coating occurs. After it dries, the product is applied for the third and last time.

During operation, the lacquer layer gradually wears out, becomes covered with cracks and scratches. Therefore, it must be restored every few years. It is enough to cover the most worn-out areas of the parquet with oil, but in the case of varnish, you may need to scrape with the removal of dirt and remnants of the old varnish.

How to insulate the floor with expanded clay - watch the video:

Despite the fact that expanded clay began to be widely used for insulating buildings several decades ago, it is still one of the most demanded materials today. This is due to the fact that in many qualities it is ready to compete even with high-tech modern heat insulators. In a word, according to standards and regulations, it is quite worthy to be used for various types of premises.

Today, there is a large selection of modern materials in implementation; in terms of their heat-saving performance, they meet the requirements of the current regulatory enactments. Expanded clay is not considered a new insulation; it has been used in construction for many decades.

1. This is the only insulation that can be placed on any base, including the ground. Do not put mineral wool or polystyrene on the ground, this is strictly prohibited by the recommended technologies.
2. Expanded clay has the highest values ​​of physical strength. According to these indicators, it is far ahead of the widely used modern counterparts.
3. Environmental friendliness. Expanded clay is made from clay, does not emit any harmful chemical compounds into the air.
4. Non-flammability. It is approved for use by fire organizations without restrictions, it is allowed to be used as an open fire barrier.
5. Low cost. This is the cheapest insulation for universal use. It is used to insulate floors, ceilings and walls. It can be used in both residential and industrial or commercial buildings.

Depending on the size, expanded clay is divided into several fractions: sand (5–10 mm), crushed stone (10–20 mm) and gravel (20–40 mm). Expanded clay is obtained after firing low-melting intumescent clay grades, has a porous structure. The production technology allows the use of various special additives to improve performance. According to the characteristics of the bulk density, the material is divided into ten grades, designated by numbers from 250 to 800, indicating the weight of one cubic meter in kilograms.

The technology consists of several stages, each with its own characteristics and requirements of building codes and regulations. Floor screed with expanded clay is made of three layers: dry expanded clay, concrete mix with insulation and clean cement-sand screed. How to make insulation?

Important. To increase the efficiency of insulation, it is recommended to use several fractions of expanded clay at the same time. Small fractions will fill the air chambers and make the insulation denser and more resistant to stress.

Step 2. Prepare the base surface. If the insulation is to be used on the ground, then it must be leveled, a layer of rubble ≈ 5 cm thick, on top of a layer of sand about 5 cm thick. The base must be thoroughly tamped.

If the insulation is used on a concrete base, then you need to remove the old coatings and debris. If large cracks are found, they must be sealed with any solutions.

Expanded clay allows you to insulate inclined surfaces, leveling the surface is done with insulation. This greatly speeds up and reduces the cost of construction work.

Step 3. Make waterproofing. One of the disadvantages of expanded clay is a significant decrease in heat conservation characteristics with an increase in relative humidity. The material is porous and absorbs water. The presence of water in the granules significantly increases the thermal conductivity coefficient. But not all thermal insulation materials can be used for waterproofing. Granular insulation, creates significant point forces on waterproofing materials. In these places, there are great risks of damage to film waterproofing materials: plastic film, nonwovens, etc.

If the base is concrete, then it must be insulated with mastics based on modified bitumen. The brands do not really matter, they all perfectly fulfill their tasks. Professional builders recommend applying at least two layers of mastic, carefully treating the most problematic areas. Expanded clay can be poured only after the mastic is completely dry, the specific time depends on the brand.

It is a little more difficult to do waterproofing on the ground. The finishing base is compacted sand, it can give uneven shrinkage under load. The most durable materials should be used as waterproofing materials on such bases. Roofing material with two layers of coating with modified bitumen is considered optimal.

Step 4. Pour a layer of expanded clay. Marks should be made around the perimeter of the room using a hydro level or a laser level. One mark is the height of expanded clay, the second is the height of the cement screed and the third is the height of the final flooring. The thickness of the layers must meet the requirements of the design documentation or self-made calculations. Using a long strip (rule), level the surface of the poured insulation.

Practical advice. Walking on the surface of expanded clay during other construction work is very inconvenient, it falls through underfoot. In order to facilitate further work and improve the bearing performance of the screed, it is recommended to put a reinforcing mesh on dry expanded clay. The specific parameters of the mesh are selected taking into account the possible maximum loads.

Check the position of the insulation, if necessary, level out large elevations or fill in the grooves.

Step 5. Prepare the sub-screed mortar. It must be done from two or three parts of expanded clay and one part of a cement-concrete mixture of the usual composition. This layer serves to fix the coating and additionally insulates the floor. The thickness of this layer is within 5–8 centimeters.

The screed laying technology has its own characteristics

1. For lighthouses, you need to take special metal elements with a wide base, the strips should be purchased in hardware stores. If this is not possible, then you will have to make them yourself from slats or boards. The length of the lighthouses is approximately 1.5–2.0 meters, the slats should be as even as possible. Knock down the boards with the letter T, the base must be put on expanded clay.
2. Do not try to make the fill perfectly even, the slats are loose, it is impossible to keep the rule at a constant height. The final leveling is done with a second layer ≈ 2 cm thick. If the volume of the solution is large, then to walk on expanded clay, put several boards, make a temporary path.
3. Try to take a long rule, work as far away from the lighthouses as possible, this will help to reduce their "wobbling".
4. Along the perimeter of the room between the wall and the screed, special gaskets are used to dampen the thermal expansion of the screed.

The first lighthouse should be done at a distance of 30 centimeters from the wall, the distance between the next depends on the length of the rule, they should be located about thirty centimeters closer.

You can additionally fix the lighthouses with plaster or cement mortars. This will make the work somewhat easier, but they should still be done very carefully. Install the lighthouses below the level, if there is a laser device - great. It is very convenient to work with it, the performance of all construction works is much faster and their quality is increased.

Do not rely too much on floor insulation with a solution made using expanded clay. During preparation, the granules of the insulation are filled with water, the conductivity of heat increases significantly, the effectiveness of such a heater is rather low. Use the prepared solution only for fixing the top layer. This method is used to strengthen the top layer of insulation and to facilitate the final leveling of the screed.

After pouring, you need to give time for the solution to harden. If for ordinary screeds a day is enough so that you can continue to carry out work on the installation of floor coverings, then in the option of using expanded clay, the waiting time increases to at least seven days. The fact is that the cement slurry does not have a continuous support area, and individual expanded clay granules are very mobile.

Simplified technology of floor insulation with expanded clay under the screed

Among the advantages of expanded clay insulation, one more should be called - the ability to hide all engineering communications in the insulation. This increases the safety of operation, minimizes the likelihood of accidents due to mechanical damage or violation of the recommended operating conditions. In addition, it does not restrict access to pipelines or electrical cables, if necessary.

The main difference is that this method does not require making a leveling finishing screed. Expanded clay is mixed with a cement-sand mortar in a ratio of 1: 5, this mass is simultaneously used for insulation and a screed.

Advantages - the work is accelerated several times, the presence of waterproofing is not critical. Expanded clay granules are protected from the penetration of additional moisture by a cement composition. Another plus - the insulation is not afraid of cyclic static and dynamic loads. To increase the bearing capacity, it can be poured in two layers, and a reinforcing mesh can be laid between them.

Disadvantages - reduced properties of thermal insulation, the need to increase the minimum thickness of the insulation and an increase in the load on the supporting bases. The method is recommended to be used during floor insulation on the ground.

To increase the strength of the expanded clay screed, it is recommended to moisten it with water twice a day. This must be done carefully, do not fill with water, do not allow dry expanded clay to get wet. Watering significantly improves the physical performance of the screed, the chemical reactions of the cement slurry proceed in a favorable mode. You need to water the screed for two to three days, the exact time depends on the weather. At high temperatures, the number of soaks increases; complete drying of the top layer of the screed must not be allowed.

If the operating conditions of the building require an increased height of the expanded clay insulation layer, then it can be stacked in bags. Plastic bags increase the stability of the position of the granules, expanded clay does not crumble under the feet of the master, there is no need to use special additional devices and devices. For the final leveling of the surface of the filling, a layer of fine fractions with a thickness of 2-3 cm is added from above. This technology allows to reduce the time by 30%.

If possible, do not use expanded clay floor insulation technologies using cement milk. The strength of the base will increase, but the heat saving effect will be significantly reduced. There are many other building techniques for increasing the load-bearing capacity without compromising the thermal performance of the floor.

Warming with expanded clay is very beneficial to do in outbuildings or garages. Especially if the construction site is uneven, and it is impossible to do earthwork for various reasons. Expanded clay will independently even out the differences in the base in height up to ten centimeters, an increase in the amount of material does not have a noticeable effect on the change in the initial estimated cost of the object.

The tangible effect of floor insulation with expanded clay can be achieved with a layer of insulation of at least 15 centimeters. This must be borne in mind when choosing the type of base for the screed. Not all rooms allow flooring due to such a significant reduction in the height of buildings.

The more airtight the top waterproofing, the higher the thermal insulation performance. It increases due to the absence of air convection, waterproofing serves as a reliable obstacle to the movement of warm and cold air masses. The optimal method for the upper waterproofing of the floor screed is ordinary plastic wrap.

Video - Insulation of the floor with expanded clay under the screed