Insulation of a wooden house with expanded clay. Technology of floor insulation using expanded clay

Insulation of the floor, walls, and other parts of a wooden house usually occurs with the help of 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 appropriate (floor insulation can be done with it, but walls and ceilings are not). The article will consider the pros and cons of expanded clay as a heater, as well as instructions on how to use it to insulate the floor and ceiling.

Features of warming 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, ceilings have excellent vapor barrier performance;
have low resistance to mechanical damage, are not refractory;
wooden houses immediately after construction significantly settle down (have a large shrinkage coefficient);
have good thermal insulation properties.

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

Expanded clay - one of the most popular insulation 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 a heater

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

In fact, this is such a powdery shale clay. The material is really very cheap, while in terms of performance it is not inferior to sawdust, polystyrene foam, or other types of insulation used in wooden houses.

The scheme of insulation of the foundation of a frame house using expanded clay

This type of insulation boasts the following advantages:

it has complete biological safety (for the human body, this material is harmless, insect larvae cannot appear there: it is for this reason that floor insulation 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 through mice and rats, which are often “companions” of a wooden house);
fire resistant;
has a small weight (lighter - only foamed polymers such as mineral wool, so 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 (the insulation of the roof with expanded clay or the floor can be easily 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 drawbacks.

But here the matter is different: the “wet” material will dry out for a very long time. Moreover, it will swell and significantly increase 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 is, as noted above, quite simple. You can lay the material in 2 ways:

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

It's hard to say which one to choose. On the one hand, if the house is frame, panel, made of SIP panels, then it is not recommended to make a heavy floor with a screed there. By themselves, such houses are very light, their foundation is designed for the minimum possible load.

On the other hand, if the house consists of the same rounded or glued timber, 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.

The scheme of insulation of the roof of the 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 caveat that must be taken into account is that with this method, the expanded clay layer must be at least 10 centimeters thick.

More is possible, but less than 10 centimeters is impossible, neither sanitary and hygienic nor engineering standards allow this. Under the screed, of course, it is somewhat more difficult to conduct insulation.

You will need the following materials:

The work is carried out in several stages:

If there was an old floor in the house, then it is completely removed, the lower surface is protected and, if necessary, leveled (the difference in surface height can range from 3 to 5 centimeters, but no more);
The surface is completely protected from dirt and dust, for which it is treated with a brush with hard bristles, after which it can be vacuumed (if there is no construction vacuum cleaner, you can also use a regular home vacuum cleaner);
If there are defects such as chips and cracks, they can be repaired with tile adhesive, mounting foam or concrete mortar;
The next step is floor waterproofing. You can make it either with the help of waterproofing mastic or, which is much easier, with the help of an elementary dense polyethylene film;
Along the perimeter of the floor to a height of 10 centimeters, an edge tape must be glued to the walls, which will prevent further thermal deformation;
Beacons are installed as for a conventional cement screed);
The first layer of expanded clay is covered in a dry way;
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 the 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 (although walls made of expanded clay are quite rare).

Comparison of physical properties of different materials

So, the ceiling insulation is as follows:

Video

You can watch a video where experts talk about how to insulate the floor with expanded clay.

Wanting to perform floor insulation in a private house using concrete floor insulation, a person quite often prefers expanded clay. Such a technology is extremely simple - for which it is appreciated by those who wish to do the work with their own hands, without resorting to the paid services of specialists.

Expanded clay granules of different fractions

However, despite its simplicity, expanded clay insulation is very effective and durable. It is not surprising that this material is still in demand, despite the appearance of a number of modern heat insulators.

When the goal of thermal insulation work is the highest possible quality of the result, attention should be paid to the insulation of all parts of the structure - that is, not only to the walls. Insulation of the floor and ceiling of the house are no less important nuances, without which the microclimate in the room will still be far from ideal.

If the issue of ceiling insulation with Izospan B vapor barrier is even more or less clear (so that warm air does not leave the room - since it will rise up), then the need for floor insulation is often forgotten, considering it unimportant.

As a result, it will not be very pleasant to walk on the surface after finishing work is completed: because of the cold. Moreover, in the room itself, the temperature can be normal and comfortable, but walking barefoot on the floor is already cool.

The most common reason for this is an uninsulated basement. The cold and moisture reigning in it lead to the fact that the ceiling between the basement and the rooms on the first floor also freezes. As a result, the floor surface in the living area will be cold, and this will not be affected in any way by the insulation of the walls or ceiling.

2 About the use of expanded clay as a heater (video)

Bulk materials began to be used to insulate houses more than one decade ago - much earlier than foam plastic and mineral wool appeared. Of course, initially it was not expanded clay, but sawdust, sand and clay.

This material, like the infrared warm floor under the tiles, began to be widely used as an insulator about a few decades ago. He gained popularity very quickly, and has not lost it to this day (whereas the once popular polystyrene and mineral wool are gradually losing demand, giving way to more convenient counterparts).

Expanded clay itself is a small pebbles that have a rounded shape. For its production, clay and shale-containing rocks are used, processed in a special way: under the influence of high temperatures (over +1000 degrees) and centrifugal force.

The raw material is rapidly rotated in a large red-hot oven, forming into small granules with different diameters and "baking".

Expanded clay insulation is most often used for the floor, as well as for the ceiling (from the side of the attic). Less commonly, the material is used for backfilling into voids between partitions - that is, for wall insulation.

Let's consider why it is so valued and why it is so popular to insulate the floor (and other parts of the house) with expanded clay. The list of advantages of the material is as follows:

A layer of expanded clay poured onto the floor

low thermal conductivity (0.1-0.18 W / mK) like polyethylene pipes in underfloor heating systems;
improving the sound insulation of the room;
lightness (and therefore - the absence of a large load on the floors - which is important in a wooden house);
environmental cleanliness (unlike most modern materials, natural clay is used to create expanded clay);
absolute safety for humans, both under normal conditions and at elevated temperatures;
incombustibility;
cheapness;
durability;
biological neutrality (even when saturated with moisture, the material does not contribute to the appearance of mold);
lack of interest in insects and rodents (a great option for floor insulation in a private house!).

By the way, with regard to thermal conductivity: if we compare a layer of expanded clay with a thickness of about 10-12 cm, in terms of efficiency it is equal to about 25 centimeters of wood or almost 100 cm (!) Of brick. However, at the same time, it is several times inferior to the same foam or mineral wool, whose thermal conductivity is 0.04-0.05 W / mK.

Of the significant drawbacks, only poor moisture resistance can be distinguished - with prolonged contact with moisture (or when a large amount of water gets on the insulation at once), expanded clay absorbs it, and dries for a long time.

As a result, the weight of the layer increases and its characteristics deteriorate. Thus, we can draw a simple conclusion: when working on insulation with expanded clay (it doesn’t matter what exactly - the floor or the ceiling) - it is very important to follow the correct technology (which we will consider below).

Floor insulation with expanded clay between the lags

Now let's figure out how good the method of such isolation is:

no need to install a complex multi-layer structure (as, say, when using mineral wool);
no need to adjust the material (whereas polystyrene or mineral wool - you need to cut it into pieces of the right size);
simplicity and speed of application;
the possibility of carrying out all stages of insulation with your own hands, without the use of special equipment and tools (both for the floor and for the ceiling);
Can be used on uneven surfaces.

Of the significant shortcomings, only one nuance can be distinguished: this is the need to use a large layer of backfill. Where you can get by with a sheet of foam plastic 5-10 cm thick, you will need a layer of expanded clay 15-30 cm.

It is difficult to call this a significant problem, since the heat-insulating "pie" when using foam plastic also comes out quite thick. The disadvantage is felt if floor insulation is required in a room of standard height (about 2.3 m). In this case, the loss of even 10 centimeters will be noticeable, and 20-30 will completely make the room uncomfortable and uncomfortable.

The material itself, like Isospan AM, can be different. The differences are primarily in the size of the granules. It could be:

Crushed stone - obtained by crushing large pieces. The granules can be of different sizes. It is used to backfill the base layer.
Gravel - obtained according to the technology described above (during firing and during the rotation of the drum). The diameter of the granules is from 5 to 40 mm.
Sand - the smallest (up to 5 mm in diameter) granules. They are good because they allow you to tightly fill in the existing cracks, cracks, recesses.

Dry floor screed on expanded clay

Another way to classify a material is its density. In this regard, expanded clay is divided into 10 categories - with a density of 250 to 800 kg / m³. It goes without saying that the greater the density, the more efficient, but also the more expensive the insulation.

Despite the fact that expanded clay insulation (it doesn’t matter - the floor or ceiling of the house) is many times easier than using the same foam or mineral wool, the technology has a number of features. It is important to observe them, because otherwise the insulation layer may be saturated with moisture - this is the main problem that negligence during installation can lead to.

By the way, there are a considerable number of technologies for warming a wooden house using this material - from simple backfilling to adding granules to the solution when creating a screed. We will consider each of the existing options - they are all good in their own way.

Before starting work - you need to properly prepare the surface of the floor. For this:

The old coating is completely dismantled.
We remove dirt, dust, debris, fungus (if any) and install Izospan insulating membranes.

Now - directly to the technologies themselves. Just in case, we will also give reviews from people who have encountered their use.

The simplest and most common way is backfilling directly on the ground, between the laid lags. Previously, such insulation was most often performed, especially when it was necessary for a wooden country house. Yes, and in "full-fledged" residential cottages, this technology can also be used.

Expanded clay between the lags, covered with an insulating film

It is performed as follows:

If necessary, the earth is compacted.
Log laying is in progress.
A waterproofing layer (for example, roofing material) is laid on the ground between the lags, in several layers, overlapping each other by at least 10 cm and entering the walls.
Expanded clay backfilling is in progress. It is best to combine all 3 types mentioned above (sand, crushed stone, gravel).
A vapor barrier is being laid (for example, a polyethylene film), in several layers, with an overlap of 10 cm.
Laying floor boards and further fine finishing.

The same method is also applicable in cases where the ceiling is insulated from the side of the attic (if it is required to equip a room on it).

Alexey E., Krasnodar, 59 years old:

I was born and raised in Siberia, and I understood perfectly well that the first thing in construction is the insulation of the house. Than in vain to burn the boiler for several months in a row - it is easier and cheaper to perform thermal insulation once with high quality and without savings. Moreover, there are technologies that can solve the problem both efficiently and inexpensively.

One of these is floor insulation with expanded clay. It was in this way that my father also insulated the house - he simply filled a layer between the lags, and on top he laid the boards. Everything is simple and fast.

And most importantly, the result is excellent: firstly, it is warm, and secondly, when repairs were made after 12-13 years, the material was almost the same as when backfilling. In general, when I built the house myself, I also chose this method, and I do not regret it.

This option can be used both in a private house and in apartments (relevant for apartments in houses built in the second half of the last century). It is performed as follows:

Wet screed on expanded clay

Several layers of waterproofing are lined, with overlapping and entering the walls.
The surface is covered with expanded clay.
The insulation layer is leveled.
A reinforcing mesh is laid on top of the expanded clay.
A rough screed of small thickness is performed.

Andrey, Voronezh, 42 years old:

I wanted to insulate a country house - I like to come there on weekends, including - in the cold season. Fortunately, I thought about insulating the walls during construction, but I didn’t think about the floor and ceiling. I didn’t want to spend a lot for the sake of a few weeks a year - after all, I’m not going to live here permanently.

I read reviews and settled on expanded clay - it’s cheap and you can do it yourself. I decided to do it immediately for the ceiling (fortunately, there is an attic), and for the floor. I made a thin screed on the floor - a neighbor helped with both the material and the work.

And for the ceiling - just poured and covered several layers of plastic film. The second year is worth it - everything is fine. In the attic, after the rain, I checked the insulation several times - everything is dry.

One of the most popular modern options. It differs from the usual (“wet”) screed in simplicity and speed - you don’t need to prepare a solution, or level it, pour anything in, or wait until it hardens - everything is ten times easier.

In fact, the technology is the same as when laying boards on logs, only gypsum fiber boards (GVL) are used instead of boards. The advantage of this technology is not only in simplicity, but also in the fact that the result is a perfectly smooth and even floor, ready for fine finishing. And if necessary, the coating can be easily dismantled (unlike a “wet” screed, which would have to be broken).

myvestaforum.ru

About material

Key varieties

To begin with, let's understand what expanded clay is and how it happens. The effectiveness of insulation largely depends on the choice of variety, so you should pay close attention to the nuances.

Expanded clay is a granular material with a porous structure. It is obtained by firing easily swelling clays. In addition to high-purity clay raw materials, the following are added to the mixture:

peat;
sawdust;
solar oil;
distillery stillage, etc.

As a result of heat treatment, granules of different sizes are formed, inside which there are sealed pores. Due to the large number of these pores, the heat-insulating effect is ensured: the high content of entrained air, isolated from the environment by walls of baked clay, significantly reduces the thermal conductivity of the material.

Depending on the particle size, the following expanded clay fractions are distinguished:

When choosing a material, it is also worth focusing on bulk density, which can range from 250 to 800 kg per cubic meter of material. The lower this indicator, the greater the volume of air involved, which means that the better the material will work as a heater.

On the other hand, the lightest fractions of expanded clay do not differ in strength, therefore they are used where the load on the material will be minimal - for example, when filling the underground space when insulating the floor along the logs.

I give these rather boring numbers only to make it clear - expanded clay is different, and it should be selected in accordance with the task. I usually focus on such indicators:

For insulation when pouring concrete, I take either sand or a sand / crushed stone mixture with a density of 500 to 700 kg / m 3.
For backfilling, I use exclusively gravel (medium and coarse fractions), with a density of up to 400 kg / m 3.

When using crushed gravel, crushed stone or sand, the level of photoabsorption increases significantly. Therefore, I draw your attention to the importance of waterproofing measures!

Advantages and disadvantages of expanded clay insulation

We figured out the types, now let's analyze the pros and cons. Let's start with the strengths:

Expanded clay is a material based on natural raw materials. Accordingly, this insulation does not contain volatile substances and toxins, therefore it is completely safe for both humans and the environment.
Porous granules retain heat well, in addition, they are a good sound insulator. This property will be very important when you decide to use expanded clay as a heat-insulating material in an apartment in a multi-storey building.

The small size of the granules and their high flowability make it possible to fill almost any cavity with raw materials. In principle, if desired, the substance can also be used as a wall insulation - in any case, the efficiency of such filling will be higher than that of large cavities filled with air.
The small mass of expanded clay provides a significant reduction in the load on the foundation and load-bearing structures. Even in the case of using expanded clay concrete - a mixture of granules with cement mortar - the weight gain is very significant.

Finally, the plus is the quite reasonable price of the material. A cubic meter of expanded clay costs about 1200 - 1500 rubles, and a bag (0.05 cubic meters) will cost us 50 - 80 rubles. So the savings on insulation compared to other materials appear to be very significant.

When deciding which expanded clay is better to take for thermal insulation of the floor, one should not forget about its shortcomings. I wouldn't call them fatal, but not to mention them is to give you incomplete information.

An important disadvantage is the fragility of the material. Fractions with a low density are broken into pieces without any effort at all, therefore, it is necessary to store, transport, and stack the granules with the utmost care. Damaged expanded clay gravel retains heat worse: efficiency losses can reach 15 - 20%.
Water absorption can also be considered as a disadvantage. Burnt clay is prone to the accumulation of moisture in the pores, therefore, for example, when insulating the floor in a bath with expanded clay, I always lay one additional waterproofing circuit. At the same time, the costs increase slightly, but I guarantee that under the floor I don’t have a “reserve” of moisture that I don’t need at all!

Finally, the most important drawback, from my point of view, is the need to backfill a thick layer. Expanded clay as a floor insulation effectively “works” only when laying from 20 cm (and on the ground, I would generally set the lower bar at the level of 30-50 cm), so that in low rooms a very significant floor rise is possible.

Here, in theory, there should be a conclusion about the effectiveness of the material, but I do not see any particular need for it: expanded clay is a heater with its own advantages and disadvantages, and like any building raw material, it can be used. The main thing is to do it right, and if you are wondering what lies behind this "right" - you are welcome to the next section.

How can you do?

Expanded clay screed

In industrial applications, expanded clay most often acts as one of the components of expanded clay concrete. This material is used to solve various problems, but it is also suitable for pouring screeds.

Depending on the planned loads, I use different proportions of the mixture. The most relevant of them are given in the table:

If you take a cement of a different brand or expanded clay of a lower density, you need to make appropriate adjustments to the recipe.

The preparation of high-quality expanded clay concrete requires a construction mixer. If not, try to rent, because all my attempts to achieve a more or less acceptable result by mixing the solution with shovels have failed.

Instructions for preparing the solution will be as follows:

Pour water into the mixer, a little less than necessary according to the calculation. We leave a small volume of liquid for topping up - this will allow us to adjust the consistency of the solution.
Add sand and cement to the water with constant stirring in portions.
Only after the completion of the previous operation, we begin to introduce expanded clay. We add it in portions, trying to make it evenly distributed throughout the volume.
Stir the mixture slowly until you get the consistency of a thick dough. At the same time, it must remain fluid, so if necessary, add water.

The resulting claydite concrete is highly versatile: it can be used to pour a sufficiently warm floor in the garage, make a screed for tiles, linoleum or laminate, concrete the base of the basement or basement, etc.

In any case, the material is used in exactly the same way as a conventional mortar: it is poured onto a base that has been leveled and covered with sand, leveled and smoothed. Drying the solution takes about 28 days, while for the first two weeks I keep the surface of expanded clay concrete under plastic wrap, periodically moistening to avoid cracking.

Expanded clay under the screed

On the question of whether expanded clay granules can be used as a heater under a cement-sand screed, I will also answer positively. True, it is important here to correctly assess the potential load: for a dwelling, such a solution would be acceptable, but for a garage or barn it is hardly suitable. It's all about the already mentioned fragility of fired clay: under high pressure, it will begin to crack, and not only the thermal insulation capacity will decrease, but also the strength of the floor.

The process of floor insulation I spend like this:

I subject the base of the floor to thorough waterproofing: both mastic and film material are suitable. It is important to protect not only the floor from moisture, but also the lower part of the walls - we remember that the thickness of expanded clay backfill can reach half a meter.

When laying on the ground under waterproofing, a clay castle will not be superfluous - a layer of clay-sand mixture up to 15 cm thick.

I install beacons on top of the waterproofing. They must be high enough, because standard mortar slides are not suitable as supports here. I use wooden bars impregnated with a moisture-proof compound, on which I fix the beacon profile.
On lighthouses I fall asleep expanded clay. I distribute the granules as evenly as possible, but do not compact so that the material does not start to crack.

I am preparing a sufficiently liquid cement solution to fix the insulation. I pour a layer of expanded clay from above in such a way that the cement fixes the surface and penetrates into the thickness of the insulation by at least 10-20 cm, fastening individual granules into a monolith.
At this stage, the beacons can be removed, and the holes can be overwritten with a solution.
After the initial polymerization of the fixing layer, I fill in the main screed (if necessary, then over the wire mesh reinforcement). I level the screed, and smooth its surface to remove irregularities.

In principle, you can follow the example of most builders, laying the screed immediately on the expanded clay backfill. But still, I prefer to spend some time and go for a slight increase in the cost of the structure, providing a significant increase in strength. On the other hand, if the loads on this section of the floor are minimal, and you are sure of this, you can save money.

For more effective thermal insulation, you can use a combined version:

waterproofing layer.
Expanded clay layer.
Fixing pouring with concrete.
A layer of high density polystyrene foam insulation.
Finishing screed for flooring.

Yes, it turns out long and expensive, but the gain in thermal insulation will be quite significant. Perfect for a child's room or bedroom!

Backfilling of expanded clay in the underground space

Floor insulation in a wooden house with expanded clay is usually performed using dry technology. This means that we do not use the solution, and the expanded clay thermal insulation layer is simply located under the rough flooring of the floor.

Here I will describe how the work on the ground base is carried out. This algorithm is more complete, so when implementing projects involving thermal insulation over a concrete slab or wooden deck (floor of the second or third floor), you can simply ignore the points on preparing the ground.

The soil in the underground space is carefully rammed.
From above, I backfill from a sand-clay or sand-gravel mixture with a thickness of up to 15 cm. I compact the backfill well.
I lay waterproofing on top of the backfill layer. Previously, glassine was used everywhere, but my choice is two layers of dense plastic film. I lay the polyethylene with an overlap, with a stop on the walls. I connect individual strips using strong adhesive tape.

I install cranial bars on the waterproofing, which will be the support for the lag. You can connect these supports with boards - this way we will divide the entire volume of the underground space into sections, and it will be much more convenient to fill it.
I fill the floor with expanded clay. I lay the material in layers of 5 - 10 cm: I fell asleep, leveled it, carefully tamped it, repeated it.

In order to have fewer large voids, experts advise mixing different fractions of the material: about 70% large and 30% finer. From the point of view of efficiency, the solution is quite justified, but it can be difficult to implement it technologically: you will have to order two types of material, and they will bring it in two trucks, which will increase costs. But if there is an opportunity, we boldly work according to this scheme!

On top of the heat-insulating layer I lay logs, which I rest on the cranial bars.
On top of the log I lay another waterproofing layer, and then I mount the wooden flooring.

An air gap between the insulation and the flooring is required: its presence is a prerequisite for high-quality thermal insulation.

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The choice of the thickness of the insulation layer

The exact value is determined by a calculation that takes into account the climatic conditions of the house, the intended purpose of the structure and the thermal conductivity coefficient declared by the manufacturer. The recommended minimum for arranging floors on the ground is 30 cm, insulation of attic and interfloor floors - 10, over an already poured or installed concrete slab or screed on the ground floor - 10.

The optimal average fraction is 10-20 mm. When calculating the height of the pie when laying this insulation on the ground, remember the need for a pillow of sand and gravel. Regardless of the thickness of the layer, expanded clay needs to be leveled horizontally, it is important to make sure that there are no protrusions and holes.

Thermal insulation methods

The following options are distinguished:

Dry, in which expanded clay under the floor is laid to the level of the lag on a base protected from moisture and is laid on top with rough boards. The advantages of this method include simplicity and high speed of work. At the same time, fired clay granules retain their maximum energy saving abilities.
Wet, in which expanded clay is mixed with cement-sand mortar and poured over leveling beacons. They are chosen with significant differences in floor height, its pluses include the formation of a solid and suitable for immediate installation of the flooring surface, the minuses - a decrease in the insulating abilities of the granules.
Combined or semi-dry - with dry filling, thorough compaction and leveling, followed by concreting. With obvious advantages (the advantages of the above options are combined), this method requires caution when insulating a floor with high expected loads. The absence of a lag is compensated by the placement of reinforcing meshes, ignoring this requirement leads to subsidence of individual sections and the rapid destruction of the structure.

Scheme of actions for dry laying

Work begins with the preparation of the foundation - soil or concrete slab. The placement of dry expanded clay over rammed earth and sand and gravel pads is often chosen when insulating wooden floors, in this case, reliable isolation from ground moisture is included in the mandatory conditions of the technology, for this purpose the base is covered with 2 layers of roofing material or a thick film with adjacent panels overlapping each other . If there is a lag, there are no problems: the granules simply fall asleep between them, in the absence of them, they are pre-installed or a frame system is placed (ordinary boards are reinforced with bars and installed on the same level).

The resulting space is filled with a mixture of different fractions, there is no special need for laying a special ventilation gap (expanded clay will still settle a little during the operation of the floor). To prevent getting wet, a layer of vapor or waterproofing film is laid under the future boardwalk. The degree of its density depends on the purpose of the room - in ordinary living rooms it is better to choose a breathable membrane, in bathrooms, bathrooms and baths - materials with maximum protection against moisture penetration inside.

The scheme is suitable for floors both on the ground floor and interfloor and attic floors, only the height of the frame changes.

Laying expanded clay under the screed

This method is considered classic, the sequence of actions largely coincides with the previous one:

1. Preparations are underway. When backfilling on the ground, the surface is leveled and rammed. When insulating a concrete slab, debris is removed and its condition is assessed, if necessary, large defects are eliminated or individual sections are restored.

2. A waterproofing layer is mounted on a prepared, clean and dry base, the variety is selected taking into account the operating conditions. For a concrete slab, a thin film is sufficient; when insulating the floor on the ground, high-density roll materials are used. The canvases are placed with an overlap, with a call to the walls, the joints are closed with adhesive tape. The final decking must be solid with top edges above the expected level of the screed.

3. Marking and installation of beacons. The leveling elements are necessarily fixed with a solution, the filling of the insulation granules is carried out after its final hardening. At this stage, a damper tape is placed around the perimeter of the walls.

4. The space between the beacons is filled with a mixture of expanded clay of different fractions, the resulting layer is compacted several times and filled with cement milk or liquid CPR. To improve resistance to biological effects, a little primer with antiseptic properties is introduced into the composition.

5. The future screed is reinforced with a metal mesh with an average cell size (up to 5 × 5 mm).

6. A high-quality cement-sand composition is being prepared, poured with separate patches 3 cm thick, but without technological interruptions. It is leveled and covered with a film, during the first 5-7 days the surface is sprayed with water. The work is completed by removing excess waterproofing and grinding the hardened mortar.

The nuances of laying technology

Thermal insulation of the floor with expanded clay raises its level by at least 12 cm, it is extremely important to correctly determine the thickness of each layer. When arranging them on the ground, many make the mistake of falling asleep insulation fractions without prior alignment, ignoring the need for waterproofing. As a result, in addition to incorrectly calculating the amount of material, the insulation layer does not fulfill its functions due to uneven distribution, and when it is closed with a screed, and not with logs with boards, it also sags. The best reviews are observed in floors with a pillow of sand and gravel, the increase in labor costs always pays off (does not push down and does not freeze).

Regardless of the method of performing thermal insulation, a number of requirements are met:

1. Material with different fractions and shape is used. An exception is allowed when warming the floors in a frame way, in this case, the majority are light rounded granules with a solid shell, the proportion of heavy sand is minimized.

2. All wooden elements (logs, fasteners, frame boards) are pre-treated with antiseptic compounds. Backfilling of expanded clay is started after their final drying. The same applies to other work with the possible release of moisture: fixing the beacons on the mortar or preparing the concrete slab.

3. When choosing steam and waterproofing, it should be remembered that bulk material resists moisture influences quite well, but it does not remove it well from the inside after getting wet without ventilation. At least one layer must be membrane, that is, perforated. An exception is made only with wet laying, when all the insulation granules are enveloped in cement mortar. Violations of technology include insulation flooring without lifting the walls and entering neighboring areas, in this case the layer remains unprotected from moisture penetration from the side.

4. When backfilling expanded clay under the future cement screed, its displacement is avoided in every possible way. With a high thickness of the insulating layer and a large area of the room, the material can be laid directly in bags and only then closed with smaller fractions. In any case, before the main pouring, the granules are fixed with a liquid cement mortar.

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Advantages and disadvantages of expanded clay as a heater

Advantages expanded clay as a heater:

Good thermal insulation properties, the thermal conductivity of expanded clay varies from 0.10 to 0.18 W / (m * C).
The vapor permeability coefficient is 0.21-0.26 mg / (m * hour * Pa).
Density varies from 200 to 800 kg/m³.
Moisture absorption is from 8 to 20%.
Expanded clay is resistant to temperature fluctuations.
Absolute environmental friendliness.
Good soundproofing.
The material is non-flammable and does not emit harmful substances.
The expanded clay structure is porous, which gives it lightness and does not give an extra load on the foundation of the house.
Durability due to resistance to destructive factors.
Ease of installation.
Affordable price.
Resistant to decay and fungus.

But with all these advantages, the material has a number of shortcomings:

The fragility of the material (you need to remember this when filling expanded clay).
Expanded clay absorbs excess moisture, but does not give it away immediately, but dries out gradually.
It is better to use it as a dry backfill.

Expanded clay floor insulation technology

There are various ways of warming expanded clay floors:

dry - floor insulation with lags;
combined - insulation under the screed;
wet - screed with expanded clay;
ground laying.

Floor insulation with lags (dry method)

When warming the floor in a dry way, the logs are impregnated antiseptic or drying oil to prevent rotting. If the floor of a house under construction is insulated, then the width between the lags should be 35-40 cm.

A waterproofing film is laid on the logs to protect the insulation from moisture. The film should be laid so that it rises along the wall 3-5 cm above the expanded clay. Next, expanded clay is poured between the lags and leveled. The layer must be at least 10 cm.

Then lay the waterproofing film. Boards are attached on top of it or plywood sheets 12 mm thick. When using plywood with a thickness of 6-8 mm, it is necessary to lay it in 2 layers.

Floor insulation with expanded clay under the screed (combined method)

In the combined method, a film is laid on a wooden or concrete base waterproofing. Further, expanded clay is poured out and leveled. The upper layer of expanded clay is fixed with a cement composition and a reinforcing mesh.

Screed mortar applied to expanded clay and leveled on lighthouse rails. The solution consists of cement and sand in a ratio of 1 to 3 or 1 to 4, depending on the brand of cement. Often, various plasticizers and other fillers are included in the composition of the screed for ease of use and improving the quality of the floor.

Expanded clay screed (wet method)

Expanded clay screed is popular way floor insulation with a mixture of cement and expanded clay.

With granules in the mixture easier to work than when using expanded clay in bulk. And if the floors are not even and the height of the screed is large enough, then you can’t do without adding a filler to the solution.

The ratio of cement mortar to expanded clay should be about 2 to 1, and the consistency of the composition should be similar to thick sour cream.

On the floor over the waterproofing film with the help of gypsum are installed beacon rails. The mixture is applied to the surface of the film with a trowel and leveled with a special board. If a concrete floor is chosen as the top coating, then, without waiting for the cement-expanded clay screed to dry, a layer of concrete is poured.

Floor insulation when laying on the ground

The first stage of the installation of insulation is the alignment and compaction of the earth layer. Next, a sand cushion and a layer of gravel are poured. Creeps on gravel waterproofing film and expanded clay falls asleep. The top layer of expanded clay is fastened with a liquid cement mortar.

If there are future loads on the floor, they are laid on top reinforcing mesh. Then lay the waterproofing film.

Materials and tools

For work on warming the floor of a house or cottage with expanded clay, you will need the following tools:

Master OK;
rule;
putty knife;
a hammer;
screwdriver

materials required for insulation:

expanded clay;
plywood;
self-tapping screws;
cement-concrete mixture;
waterproofing film;
vapor barrier film.

In conclusion, we can say that when choosing a heater, you need to build on its properties and characteristics. A screed with expanded clay allows you to achieve not only perfect alignment, but also to improve the insulation characteristics of the structure.

More complete information about expanded clay as a heater can be obtained in the article "Expanded clay as a heater: the right choice of weight and fraction."

See the video for a master class on floor insulation with expanded clay using a dry screed method:

See the video below for a master class on expanded clay screed:

The popularity of creating environmentally friendly buildings in a forest or remote area from the city is growing every year.

To do this, all owners strive to use appropriate materials both for organizing the structure itself and for interior decoration in the premises.

The most famous eco-building option is a wooden house. Often there are questions about how and with what to insulate the floor in this building, since many materials are not suitable for environmental friendliness. One of the solutions to the problem is to insulate the floor with expanded clay in a wooden house.

Insulation of the floor of a wooden house, options for insulation

Wood is a material that holds heat well. Only the structures of wooden houses are made in such a way that the supporting elements of the flooring are wooden logs, which are located at a distance of 40-80 cm from each other.

These elements are made of edged boards with dimensions of 50 x 150 mm and 50 x 200 mm.

They are laid on the initial level of the building, the strapping of which is bars 150 x 150 cm or 150 x 100 cm, connected to each other “overlaid”. The binding rests on the foundation.

It depends on the foundation how to perform the subfloor.

The draft floor in a wooden house is often mounted on logs.

For the construction of wooden houses, 3 foundation options are most often used:

monolith;
strip foundation;
piles.

Each of these types has its own characteristics and recommendations for use in certain conditions. If a wooden house is placed on a monolithic foundation, then the concrete itself will be the rough flooring, but if on a pile or tape, then the subfloor is made of wooden boards, which are hemmed from the bottom of the log.

To prevent cold air from entering the building through the floor, it is recommended to insulate it. The insulation is laid on the subfloor, which is pre-covered with a waterproofing film.

To date, the range of heaters that are suitable for use in wooden houses is quite diverse.

For floor insulation use:

products based on mineral and basalt wool;
glass wool;
Styrofoam;
expanded polystyrene;
expanded clay.

Each material with which insulation is made has certain thermal conductivity indicators. The same insulation (its type) can be produced with different thermal conductivity and density.

Expanded clay, as a floor insulation in a wooden house, its properties

Expanded clay is an environmentally friendly material

Expanded clay is considered a natural and environmentally friendly material that is widely used in construction work for various purposes.

Many professionals consider expanded clay to be the first insulation that has excellent thermal insulation and sound absorption properties.

This material is also used for the production of building blocks, as well as for organizing a screed and a rough floor surface.

This material absorbs sound well and is less dusty than concrete screed.

Expanded clay, as a heater, has unique properties, it can simultaneously cover and insulate the floor.

This building material is widely used in construction.

It has a number of advantages, but there are also disadvantages.

The advantages of expanded clay include:

the material emits an insignificant amount of dust and debris, many times less than a cement-sand screed;
excellent sound-absorbing properties, due to which expanded clay is used not only for floor insulation, but also for backfilling walls;
good indicators of thermal insulation;
simple installation process that can be carried out by one person.

Expanded clay has much less disadvantages than advantages. These include the flowability of the material and its price. Despite the fact that it has been on the construction market for quite a long time, the cost of it does not decrease.

Expanded clay itself has the appearance of granules and small rounded stones. To obtain this product, a clay composition is used with the addition of shale rocks, which undergo additional heat treatment.

The formation takes place at a temperature reaching 1000 0 C until the granules are completely mixed. For more information about modern heaters, see this video:

Floor insulation in a wooden house with expanded clay

Warming or organizing a screed using expanded clay can be done in two ways. A distinction is made between the method of dry laying of expanded clay and wet (organization of a screed with the addition of cement and sand).

Floor insulation "dry method"

Before backfilling the material, line each cell with waterproofing material

Before organizing the dry method of warming a wooden house with expanded clay, it is necessary to treat the rough floor (if it is made of wood) with an insect and mold repellent, only after that it is worth laying a waterproofing membrane.

It is better to lay the film in each cell (gaps between lags) separately. If it is not possible to purchase modern waterproofing material, you can fully replace it with roofing material.

Filled granules must be compacted

After the waterproofing on the flooring is equipped, you should proceed to filling the gaps with expanded clay.

When pouring insulation into the cells between the lags, it should be distributed at the same time so that there are no unfilled areas, while slightly tamping the material. The level of the filled expanded clay should coincide with the top of the supporting logs.

To organize floor insulation in wooden houses, experts advise using this fine fraction building material so that individual granules fit as tightly as possible to each other, thereby creating a greater density of the insulated cover.

It is possible to lay expanded clay immediately in bags

Some builders use expanded clay filled in plastic bags to insulate the flooring of houses.

At the same time, the bags are selected in large sizes and the material is not completely filled into it, leaving the possibility of uniform distribution during laying.

Installation of a layer of insulation using expanded clay in bags avoids debris and dust, and also contributes to the uniform use of all material.

The thickness of the expanded clay layer is limited by the height of the log. For a certain region of the country, experts recommend an individual layer of expanded clay for floor insulation.

Insulation of the floor with expanded clay by the organization of a "wet" screed

A wet screed based on expanded clay is used as a heater, leveling cover and rough flooring, on which the finish coating is already laid.

Under expanded clay, it is advised to lay roofing material

Before laying the screed, it is worth rolling out the roofing material over the entire surface of the monolithic foundation, and its edges should go on the walls (up) by 10-15 cm. The screed - insulation should not come into contact with the frame of the house.

The proportions of the solution for organizing the coating are as follows, for 1 kg of cement there are 4 kg of expanded clay and 3 kg of sand. Water is added to the composition during kneading at the discretion of the builders. For more information about floor insulation with granules, see the emt video:

When organizing both wet and dry screeds, it is necessary to calculate in advance the amount of expanded clay for flooring a certain area.

To do this, you need to know: the area of \u200b\u200bthe room, the thickness of the insulation layer and the weight of 1m 3 of the material. To correctly create a solution for a wet insulating screed based on expanded clay, you can use the examples of material ratios shown in the table.

Expanded clay is a universal building material that does not lose its popularity and competes with other types of insulation. Thermal insulation and noise reduction are the most important properties of expanded clay, which it does not lose even after many years of operation.

The heat in the house largely depends on the condition of the floors. A cold floor can absorb from 10 to 15 percent of the heat generated by heating devices. Therefore, during construction, this structural element should be thoroughly insulated.

An excellent type of insulation is expanded clay. If you do not know how to use it for this purpose, we recommend that you read this article.

A bit of history

Expanded clay owes its appearance to defective bricks. At the beginning of the last century, red brick was industrially produced. When the duration of the heat treatment increased or the temperature exceeded the allowable one, the brick turned out to be burned out and swelled. Substandard crushed and used as a concrete filler.

If in our country bricks unsuitable for construction were not allowed to disappear, then in America porous clay plates were made specially. And they used them similarly with our marriage.

The thirties of the XX century were marked by the fact that this technology was modernized. The Soviet engineer proposed to make small porous fractions at once. Clay pellets were subjected to heat treatment in rotary kilns. A strong layer appeared on their surface. The granules were light in weight, as there were many air inclusions inside. Thus, expanded clay appeared.

Material Features

Expanded clay is simply indispensable for the household. It is used in the construction of a drainage system, they lay out garden paths, and are used in landscape design. But, first of all, this material is known as a first-class insulation.

Porous granules, depending on the size, are divided into three groups:

Small ones from 5 mm to 10 mm are the main components of expanded clay concrete blocks. In construction work, they are suitable for arranging floor screeds.
Medium-sized from 10 to 20 mm are used as insulation for floors and ceilings between floors in private houses.
The largest ones from 20 mm to 40 mm are used for floor insulation in basements and garages.

In terms of shape and structure, the material has three varieties:

Expanded clay gravel, Distinctive characteristic - porosity and rounded shape. The sizes of the balls vary between 5 - 40 millimeters.
Expanded clay sand. The particle size does not exceed 5 mm. It is formed from the remains of gravel. It is used as a filler for cement mortars and ultralight concretes.
Rubble. The dimensions are similar to gravel, but the particles differ in the presence of corners, chips, potholes. Obtained by crushing excessively coarse gravel. Suitable for filling lightweight concrete.

Pros and cons

Granular bulk material has many advantages. The main thing, perhaps, is the ratio of indicators of quality and cost. Unfortunately, it has not been without drawbacks. Therefore, one can hear opinions for and against its use.

The undeniable advantages of expanded clay:

Good thermal insulation properties. Clay, from which expanded clay is made, is itself capable of retaining heat. After foaming, air-filled pores are formed in it, due to which the thermal conductivity is significantly reduced.
Light weight. Despite the fact that when insulating building structures, expanded clay is poured in a fairly thick layer, the load on the base from its weight is small.

Easy to use. Working with the material does not require special skills and the use of special expensive equipment.
Fire resistance. Expanded clay does not burn. When heated, it does not emit toxins and unpleasant odors.
Unsuitable for rodents and insects. The insulation will not collapse from the invasion of various living creatures.

Resistant to heat and chemicals. The granules will not collapse in heat or frost, they will not lose their heat-insulating properties when interacting with household chemicals.
Soundproofing. Along with the properties of insulation, expanded clay significantly reduces the penetration of noise.
Environmental friendliness. Absolutely harmless to people and pets.
Durability. Expanded clay pillow, subject to the rules of laying, can last a century!

The disadvantages of the insulation appear during installation. To achieve the desired result, the granules are poured in a thick layer - from 10 to 40 cm. In this case, the ceiling becomes much closer to the floor, which is not always pleasant, and sometimes simply unacceptable.

In the absence or damage of the hard shell, moisture penetrates into the granules. Raw expanded clay is unsuitable for use, and it dries for a very long time. To prevent the absorption of moisture by the insulation during installation, additional materials are used: waterproofing from below and vapor barrier on top of the heat insulator. Failure to comply with the rules will lead to the penetration of moisture into the granules. Then the expanded clay will get wet, its weight will increase, and it will sag in places. Useful properties will disappear.

Styling features

There are three different ways to use granular insulation.

The dry method is preferred in wooden houses. Gravel is mixed with expanded clay sand and poured into the gaps between the lags. Thanks to particles of various sizes, the space is filled as densely as possible. The absence of gaps guarantees reliable insulation. The dry method is the fastest. It is within the power of people without experience, does not require large expenditures.

The wet method is a three-piece screed. Two parts of sand are mixed with one part of cement and three parts of expanded clay. The mixture is well kneaded with water and the floor is poured with the resulting solution. The presence of porous balls in the screed provides floor insulation.

A similar technology is used in utility rooms: garages, workshops, sheds. The method is laborious and more costly than the dry method.

With the combined method, dry granules are only poured from above with cement mortar. This results in a smooth, solid surface. After drying, make a full-fledged screed.

In order to insulate the foundation, floor, ceiling or ceiling with expanded clay, similar technologies are used. First, the site is leveled, on which expanded clay is planned to be poured. Then waterproofing is laid, it can be a plastic film or other rolled material that does not allow moisture to pass through. In order for the waterproofing coating to become solid, the joints are carefully glued with adhesive tape.

The thickness of the thermal insulation layer depends on the floor structure. The thicker the layer, the better the insulation and the more heat remains in the room. Sometimes the height of the backfill is limited by the size of the lags, sometimes it depends on the existing doorway, when an extra centimeter becomes an obstacle to the door.

On large areas it is difficult to ensure uniform laying out of expanded clay. The problem is solved by installing wooden bars or lags. Logs are leveled in a horizontal plane. Then waterproofing is laid. Granules are poured on it. The level is used again, but now for the correct distribution of the bulk product along the horizon. If expanded clay goes under the screed, the top layer is poured with cement mortar. In the dry laying method, a vapor barrier, such as parchment, is laid on top.

In order to insulate the chimney, you will have to build a casing corresponding to the shape of the pipe. Below should be a dense non-combustible material, for example, an asbestos-cement sheet. Expanded clay is loaded into the space between the chimney pipe. The upper part of the casing is closed with a lid made of the same material as itself.

Warming technology

Despite the similarity of laying bulk material, there are some distinctive features.

On the ground

The floor on the ground is appropriate in garages and basements. In winter, such rooms will not be too cold if the appropriate work is done.

To insulate the floor on the ground, the fertile layer should be removed, the ground should be leveled and thoroughly compacted. A layer of crushed stone and sand is poured onto the compacted area. Thus, there is an additional leveling of the surface.

Waterproofing will protect the insulation from high-standing groundwater. It should be placed on a prepared pillow. Then expanded clay is poured and leveled so that the height over the entire area is the same. Fixation of the top layer is carried out by impregnation with cement mortar. Next comes the layer of vapor barrier.

The insulation on the ground is completed with a reinforced cement screed. If desired, after complete drying, a wooden floor can be laid on it.

By lags

Logs when insulated with expanded clay serve a double service. On the one hand, it is convenient to level the backfill along them, on the other hand, they serve as the basis for the subfloor.

Along the logs, the granular fraction is laid on concrete bases. First, the working area is freed to clean concrete. Any flaws are eliminated. Cracks are covered with mortar, joints and corners are foamed if necessary. The logs are pre-treated with an antiseptic, and then attached to the base with corners. In this case, the upper faces of the wooden guides are displayed in one horizontal plane.

As a waterproofing, you can use:

Ruberoid;
Polyethylene;
Polymer blends;
Bituminous mastics;
Rubber hydraulic barriers.

Both the concrete surface, and the logs, and the walls along the perimeter of the room to a height slightly higher than the height of the wooden parts are subject to processing. In the case of liquid mastics, concrete is primed for better adhesion. If a film is used, it is attached to the bars with a stapler. Insulation is poured into the sinuses so that there are no empty seats, and the height is the same everywhere. Expanded clay is covered with a vapor barrier layer. Then the draft floor is installed, and the finish floor is installed on it.

On the balcony

In fact, the balcony is a fenced protruding reinforced concrete slab. Standing on a concrete floor is uncomfortable even in summer. Often, apartment owners decide to insulate balconies. Light granules are better suited for this purpose than other heat insulators.

It is not necessary to level the base. The main thing is that the new floor does not have slopes. To do this, beacon rails are installed on concrete covered with insulation. Beacons can be attached to the slab with mortar or plaster. The distance between the parallel rails should not exceed the length of the rule. The smaller the step between the beacons, the easier it is to get the job done.

The height of the warm layer is equal to the beacons. The finished pillow is poured with a cement composition. After hardening, a full-fledged screed is made on top. If desired, on the loggia and on the closed balcony, a wooden floor can be laid on top of the screed.

In a wooden house

Expanded clay is widely used in the private sector. And this is not surprising, since the material is so unpretentious that homeowners work with it on their own.

Expanded clay insulates the floors of the first floor and attic floors. Granular material is used for floor insulation in the steam room, in utility rooms and living quarters. In the latter case, it is important to ensure that the dust generated during the friction of the gravel does not penetrate into the room.

A stone or concrete house is built on a foundation and has a basement or basement. In such buildings, floors are not always insulated. It is impossible to live in a frame house built on screw piles without thermal insulation. To ensure comfort in such a structure, you will have to work hard.

The funds saved on the construction of the foundation should be spent on thorough floor insulation. As a waterproofing, there should not be the simplest roofing material or polyethylene, but modern reliable building materials. Vapor-permeable moisture and wind-proof membranes will become an excellent protection against negative impacts. The rest of the work is carried out similarly to other types of floors. Exactly the same work on floor insulation will require a light wooden log house.

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

More about expanded clay
Varieties of expanded clay
Which expanded clay is better for floor insulation?
Advantages and disadvantages of expanded clay
Expanded clay insulation methods
- Dry insulation with expanded clay
- Wet laying of expanded clay
- Combined method
Expanded clay insulation under a wooden floor on a concrete base
- Materials and tools
- Dismantling of the coating
- Surface preparation
- Waterproofing
- Installation lag
- Expanded clay backfill
- Floor covering installation
Expanded clay insulation under a wooden floor on the ground
Expanded clay insulation under a concrete base
- Floor preparation
- Expanded clay backfill
- Reinforcement
- Screeding
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 insulating 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. During the firing process, fusible clays, to which peat, sawdust and diesel fuel are added, swell. Expanded clay is often used in construction as an addition to concrete in cases where it needs to be made lighter.

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

granule size;
granule strength;
material density.

By bulk density (or volumetric weight), 10 grades of expanded clay are distinguished (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 expanded clay brand 250 weighs exactly that much in kilograms.

The greater the porosity of the material, the lower its density and the higher its thermal insulation 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 the feedstock. Bulk density is determined by filling 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 grinding large fractions of expanded clay. The particle sizes here are no more than 5 mm. This sand, together with large fractions, is used for insulating interior partitions or when insulating the floor with expanded clay concrete is required. It also serves as a filler for cement mortar.

Expanded clay gravel

It is a rounded grains 5-40 mm in size with a porous structure, which are obtained in pyrogenic furnaces by swelling superfusible clay. It is fire-resistant, 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 it is intended to insulate the concrete floor with expanded clay.

Which expanded clay is better for floor insulation?

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

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

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

Advantages and disadvantages of expanded clay

Advantages

The advantages of expanded clay include:

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

Floor insulation 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, on which foam plastic or mineral wool cannot be placed directly, since they will quickly lose their useful qualities.
Expanded clay has the highest strength among other heaters.
The environmentally friendly composition ensures safe use of expanded clay, since it does not release anything into the air.
Due to its incombustibility, expanded clay has no restrictions in terms of fire safety, it can even serve as a barrier to open flames.
Expanded clay is the cheapest insulation, so for a long time and very widely used floor insulation with expanded clay in a private house, as well as walls and ceilings. In addition to private buildings, it is widely used in industrial and other buildings.

Flaws

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 do not give moisture back for a long time. Damp, heavy expanded clay begins to sag, and unevenly, which leads to floor deformation, which must be taken into account if expanded clay insulation is carried out and the floor screed of the 1st floor is carried out. To avoid this, when arranging floors, you need to carry out reliable waterproofing.

Expanded clay insulation methods

Builders use three methods of making expanded clay:

wet;
dry;
combined.

To make the technology of floor insulation with expanded clay more understandable, you should deal with each option in more detail.

Dry insulation with expanded clay

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

The material is poured between beacons or lags, and a subfloor made of plywood, chipboard or ordinary boards is mounted above it.
To protect the insulation from moisture, it is necessary to lay a waterproofing material under it.

To increase the filling density of granules, 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 much 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 beacons 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 expanded clay that has collected moisture increases greatly.

Combined method

Insulation of the concrete floor with expanded clay under the screed is done as follows:

Dry expanded clay is poured between the beacons.
Then it flattens out.
Its uppermost layer is poured with a liquid cement mortar.
When it dries, the usual screed is made on top.

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

If a large load is expected during the operation of the floor, then it is also possible to supplement the structure with a reinforcing mesh.

Expanded clay insulation under a wooden floor on a concrete base

Materials and tools

To make the insulation of a wooden floor with expanded clay, you will need:

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

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

Dismantling of the coating

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

Surface preparation

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

Waterproofing

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

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

Fix the waterproofing on the beams with a stapler, having previously filled it well in the recesses between the lags

If coating waterproofing is used, then the mixture must be applied to concrete that is free of dust, including wall sections near the floor. With this option, the logs should be on top of the protective layer. It can be coated with liquid polymers, bituminous 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.

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

Installation lag

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 along the length of the floor, then soaked with an antiseptic and dried completely.
The wooden frame on the floor must be at least 10 cm.
The extreme logs should be located 2-3 centimeters from the walls, and the step between adjacent logs should be within 50-100 cm.
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.
Logs need to be fixed to the floor using metal corners: fasten one side of the corner with screws or self-tapping screws to the log, and the other to the floor.
The extreme corners should be 2-3 cm from the edges of the lag, and the step between adjacent corners should be within 50 cm.

Expanded clay backfill

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

From above it remains to lay waterproofing and fix it with a stapler.

Floor covering installation

To the bars protruding from the insulation layer, you need to attach a subfloor made of boards, chipboard or plywood, after which you can already lay the finish coating. The film sticking out near the walls can be cut with a knife and close the gaps with decorative plinths.

Expanded clay insulation 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 soil.
Pour about 10 cm of gravel.
Fill the 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 fill it with concrete on top.
You can lay a wooden floor.

Expanded clay insulation under a concrete base

Floor preparation

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

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

Expanded clay backfill

First you need to calculate how much expanded clay is needed to insulate the floor. 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 proposed insulation layer and the area of \u200b\u200bthe 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 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 of area will need 0.1 * 20 \u003d 2 cubic meters. m of expanded clay (1 cubic meter of expanded clay = 400 kg).

The resulting amount must be prepared by mixing its different fractions.
Then, with this mixture, you need to fill the entire space between the beacons, leveling the material with a piece of plywood or a rule.
Especially carefully you need to fill the joints and corners so that there are no voids left.
Then expanded clay must be carefully compacted so as not to damage the granules.

Reinforcement

Put a large-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.

Screeding

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

After that, you need to wait until the concrete has gained sufficient strength to allow you to lay the floor.

This floor insulation with expanded clay assumes that the screed is directly laid on the insulation without additional 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 level of the floor, then this requires an expanded clay concrete screed:

At first, the surface also needs to be cleaned of dirt and dust.
Then go foam through the joints and crevices, put waterproofing.
Then you can proceed to the main process.
Fix metal beacons to the floor with cement mortar.

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.

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

Compact and level the surface, for which the floating granules are again drowned in the solution.
As soon as the screed is slightly set, prepare ordinary concrete without additives and pour over the screed, then align 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 durable base that can last for a long time. When the surface of the screed can be walked on, it should be covered with a hydro-barrier or film.

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