Nowadays, the cost of heating housing and premises in general is constantly increasing. At the same time, for some reason, salaries remain almost in place - a bad trend, but one has to reckon with it. In such conditions, almost every owner of a house or apartment begins to worry about the issue of saving energy. Today, walls, floors, ceilings, slopes are massively insulated - such measures allow the most efficient distribution of heat throughout the room due to the fact that the level of heat transfer of the building is reduced.
This article will touch upon such a difficult issue as floor insulation - let's figure out what is better for this: mineral wool or expanded clay. In principle, foam is also often used, but this is not the best option, because the possibility of ventilation, airing the ceiling practically disappears. Although, undoubtedly, the thermal insulation characteristics of the foam are at a height.
So, mineral wool and expanded clay, which is better - you can start with a review of the first material and compare everything on specific properties.
This insulation is a soft coarse fiber board or rolls. This material is made on the basis of waste from metal and carbon alloys of various minerals such as basalt. In structure, it resembles glass wool, only the latter is much worse in terms of thermal insulation characteristics. In principle, mineral wool is widely used in construction, and it is especially popular when insulating facades. However, the facade is not floor insulation - there are still different specifics.
The main advantages of this insulation are considered to be several points.
- Durability.
A rather controversial property, since in order for the insulation to last a really long time, it is necessary to ensure that there is no moisture in the space where it is installed. Weak resistance to moisture is the main drawback of the material, because if the mineral wool gets wet, then in this place all the thermal insulation qualities are instantly excluded. Of course, manufacturers have now learned how to process rolls with various moisture-proof compounds, but this does not always work effectively.
In addition, mats and rolls are afraid of mechanical damage, that is, simply speaking, they can break even due to the activity of mice. Therefore, the issue of durability is still mostly dubious. It is difficult to 100% protect such insulation.
- Fast installation.
This is true, however, it is also controversial - which is easier - to roll out the rolls on a plane or fill the space with expanded clay? There is not much difference in complexity. Therefore, in comparison with working with expanded clay, this quality is definitely not an advantage.
- Fire resistance.
Likewise, expanded clay is also not afraid of fire.
- Air permeability.
That is, that is - the basalt roll has good vapor permeability, due to which steam, in theory, will not accumulate in the floor space. However, if the same quality is applied to expanded clay, then the same situation is visible here - steam passes perfectly between the scattered granules of the material and, accordingly, the vapor permeability is also at a height.
It turns out that while the roll insulator "loses" to expanded clay due to the fact that it is afraid of moisture and is not too tear-resistant.
Now it's time to consider the structure of expanded clay.
Expanded clay as insulation
In fact, it is a free-flowing material with pores. The pellets are lightweight, which, in general, does not differ much from the weight of cotton wool. Expanded clay is made on the basis of clay, which contains about 30% quartz, and, as you know, clay is a natural, natural insulation that does not emit any harmful fumes.
If we compare the latter quality with mineral wool, then the latter is not so good in this regard, because it contains small dust-like particles that are harmful to human breathing. In principle, since the roll will eventually be covered with various layers of insulators (not counting the finishing floor itself), these impurities are practically not able to get into the air of the room, but this probability still remains.
That is, the third drawback of mineral insulation automatically arises here (the first is the fear of moisture, and the second is low tensile strength) - this is not 100% environmental friendliness.
As practice shows, it is possible to protect as much as possible from the harmful "side" of the issue only under the condition of a very competent and correct installation. And this is not always possible due to the different skill levels of the installers.
Of course, expanded clay can also have disadvantages in terms of environmental friendliness, but only if the raw material was mined in a quarry that has increased radioactivity rates. This happens very rarely, but it's still worth checking with the sellers for the availability of safety certificates for the material.
Also, when buying expanded clay, you should pay attention to the following:
- Per fraction of granules. For floor insulation, it is better to take not the largest sizes - a gradation of 5-10 is optimal.
- For porosity. The more pores in the stone, the better the thermal insulation characteristics.
- The strength of the material - this affects the service life.
Here a difficult moment automatically comes up in terms of using expanded clay - you need to try to find a good, high-quality material in order to achieve a low level of thermal conductivity. Basalt material "wins" here, as it is relatively standardized, and it is quite difficult to find a fake or a marriage on the market.
Expanded clay is not afraid of moisture, since all steam or all water simply "passes" through the pores or directly through the granules of the material. There is certainly a percentage of moisture absorption here, but it is very small compared to soft insulation.
It is worth noting such a moment as the almost complete absence of the possibility of incorrect laying of expanded clay for floor insulation. Yes, choosing a material is quite difficult, but it is very easy for them to insulate, the risk of any mistakes is minimal.
These are the main characteristics of expanded clay. Now you need to touch on the most important thing.
Specific thermal insulation parameters of expanded clay and roll insulators
So, it turns out that the advantages and disadvantages of materials are known, but what will happen if we compare their thermal conductivity? It's actually quite simple here.
For an illustrative example, you just need to take good quality insulators.
As you can see from the table, cotton wool insulation has a better level of thermal conductivity than expanded clay, which means that in order to achieve the same heat conduction effect, the expanded clay layer for the floor must be made twice as thick as it would be if basalt rolls were used.
If we talk about exact figures, then in an average climate, the required thickness of cotton wool on the floor should be about 7 cm according to SNIPs. Accordingly, for filling expanded clay, a space of about 13-17 centimeters will be needed (it all depends on the quality of the granules). Of course, the numbers can vary in one direction or another, since the specifics of the situation are of great importance, but in general, the ratio is approximately the same.
Based on all of the above information, you can summarize some results.
Conclusion
It turns out that both materials are good in their own way, and at the same time, each has its own specific drawbacks.
Basalt wool is not so environmentally friendly and durable, but it needs less space for its installation (but more professionalism).
And expanded clay as a heater is important to use when you want to achieve maximum environmental safety in the room and when it is possible to lay the required floor thickness.
So the choice is not so difficult - you just need to weigh all the features of the situation and the decision will become obvious.
Even if the heating system is of high quality, efficient and reliable, without a good insulation, these indicators are minimized due to high heat loss. You need to insulate the floor, roof, walls, floors of residential buildings. Expanded clay or mineral wool are most often used as insulation.
Expanded clay is a lightweight building material due to its porous structure, which is made from heaving clay. It is a loose, breathable material that is durable.
Minvata is a soft rolled artificial insulation. They make it from carbon alloys and metal waste. It has good technical characteristics and is durable.
Both heat insulators have advantages and disadvantages. Before deciding on the choice, you should consider the performance characteristics of each insulation. The main ones are thermal conductivity and weight. The thermal conductivity coefficient of expanded clay is 0.1, that of mineral wool is 0.04. Therefore, mineral wool releases less heat than expanded clay with the same thickness. The weight of expanded clay is 250 kilograms per cubic meter, and the mass of mineral wool is only 30 kilograms. Expanded clay is characterized by a high degree of soundproofing, which is important in the construction of residential premises. Mineral wool is not inferior in this indicator. And also the affordable price of both materials plays an important role. The choice of this or that material depends on the specific conditions of construction, financial and technical capabilities. In addition, these heaters complement each other perfectly. They are often combined. If you use building materials separately, then it should be borne in mind that expanded clay is a completely natural material and does not contain toxins. And mineral wool is a fragile and non-moisture resistant material that is unsafe for the human body, if it gets into the lungs, it has a harmful effect.
Expanded clay analogs
If expanded clay turns out to be a heavy material for the planned construction work, then other porous backfills can be selected. As an analogue of expanded clay acts agloporite - pumice, similar in structure to glass. But the material is not so environmentally friendly, it contains a variety of harmful additives. Expanded perlite is used as an option. Its thermal conductivity is like that of mineral wool, and its moisture absorption is not much lower than that of expanded clay. Expanded vermiculite will be the best option for its characteristics. The material is not toxic, expanded clay weighs less. Therefore, it has less stress on the floor.
Can expanded clay emit harmful substances
There is an opinion that expanded clay after a while can release substances harmful to the body. And it's better to use Styrofoam. But expanded clay is an ordinary red clay that can swell when exposed to high temperatures. Therefore, the assumption about the harmfulness of the material is not substantiated by anything. In addition, if you choose polystyrene as a heater, then when moisture gets into it, it will start to rot, after a year it will turn black and mold will appear. And expanded clay in this case, due to the ventilated gap, will not retain moisture in itself, it will evaporate. In addition, expanded clay is fire resistant, as well as a brick and will not be damaged in case of fire. At the same time, the foam will release substances harmful to health.
Expanded clay and mineral wool are traditional time-tested building materials. The best option would be to combine insulation. When choosing a specific one, it is important to take into account the core operational and physical and technical characteristics of both.
The most important criterion when choosing building materials used for the construction and arrangement of any structure is thermal conductivity. With a decrease in its value, the temperature in the rooms increases, and the cost of heating them decreases. The best thermal insulation characteristics are inherent in materials with a closed-cell structure. In construction, expanded clay is often used, the high popularity of which is also due to its relatively low weight, excellent sound insulation properties, and an affordable price.
According to the reference data, the coefficient of thermal conductivity of this material is 0.1 - 0.18 W / (m * K). The value of this indicator is influenced by a combination of factors, the main of which are:
- humidity;
- the size of the granules;
- bulk density, layer thickness.
To exclude the dependence of the thermal conductivity of expanded clay on the presence of moisture, you should take care of the waterproofing of the floor in advance.
Expanded clay as insulation
Classifying such a heater by the method of production and the size of the granules, there are several of its varieties:
- gravel;
- crushed stone;
- sand.
The first one is round grains 2-4 cm in size, having a porous structure, covered with a strong shell. It is the presence of closed cells containing air that makes it possible to use expanded clay gravel as a heater. It is obtained by swelling light types of clay. This fraction is characterized by the best thermal insulation properties.
Expanded clay crushed stone is a product of crushing expanded soft clay into fractions of 1-2 cm in size. As a result, elements are formed that have an irregular, often angular shape. If only grains of this type are included in the composition of the insulation, then the thermal conductivity of expanded clay will be slightly higher.
A by-product resulting from the production of the two main fractions is expanded clay sand, which is a grain size of 0.5-1 cm. It has the worst thermal insulation properties in comparison with gravel and crushed stone. This type is used mainly as a porous filler that is part of a concrete screed.
Influence of bulk density and layer thickness on total thermal conductivity
Provided that equal thermal insulation properties are achieved, the layer of expanded clay gravel will have a smaller thickness in comparison with crushed stone. The floor load in the first case is lower - this is due to the difference in the bulk density. This parameter characterizes the ratio of the total mass of granules (in this case, expanded clay) to their total volume without taking into account the gaps between them and inevitably emerging chips.
The density of expanded clay takes values from 250 to 800 kg / m3.
In practice, a mixture of three fractions is used as a heater: gravel, crushed stone, sand. In this way, the greatest rigidity and the smallest layer thickness are achieved, and the convection movement of heated air through the resulting voids between the granules is prevented. Therefore, when calculating the height of the expanded clay layer, it will be more correct to be guided by the value of the true density, which is 1.5-2 times higher than the bulk density. Its recommended thickness when laying on the ground is 25-30 cm. When insulating a concrete floor, it should not be less than 10 cm.
Comparison with mineral wool and foam
Polyfoam has good insulation properties, which are expressed in a specific value - 0.047 W / (m * K). It is widely used for the decoration of apartment or private houses, office buildings. But, despite the seemingly great efficiency of the foam plate (relative to the expanded clay layer), this is far from always the case.
Where it is required to arrange surfaces subject to frequent mechanical stress, significant loads, it is better to use a mixture of gravel and crushed stone. However, with thermal insulation of walls, the floor of the attic, polystyrene foam will be more effective. In addition, it has a low weight, is characterized by a smaller thickness compared to other heaters. All this allows it to be used where excessive floor loads are unacceptable.
When insulating with foam, no additional waterproofing device is required. However, like most polymeric materials, it is flammable.
Mineral wool is also widely used to protect housing from cold weather. But even in this case, it is not worth comparing the thermal conductivity of mineral wool and expanded clay, even though its value in the first case is much lower (0.048-0.07 W / (m * K)). Such heaters are used in different cases. So, for cladding walls and ceilings in private houses from the inside of the room, neither gravel, nor crushed stone, nor, moreover, expanded clay sand is absolutely not suitable. Minvata will be practically irreplaceable here.
However, it is a rather voluminous insulation material. Any attempts to compress it will lead to a decrease in the volume of air contained in the mineral wool, and therefore to a decrease in efficiency. In addition, the use of mineral wool should be extremely careful. This type of insulation has a negative effect on the human body. This characteristic suggests that all installation work should be done only with the use of personal protective equipment.
The efficiency of even the most powerful and modern heating system is reduced to zero without high-quality and reliable thermal insulation, the main task of which is to reduce heat loss. Most often, expanded clay and mineral wool are used to insulate walls, roofs, floors and floors of residential buildings. Which of these materials does the best job?
The construction of buildings implies their mandatory insulation with the help of materials intended for this. From any of them, we demand low thermal conductivity, light weight, soundproofing qualities, fire resistance, environmental friendliness and low cost. Before us are two of the most popular heat insulators: expanded clay and mineral wool. Each of them has its own advantages and disadvantages, depending not only on their "innate" physical and technical parameters, but also on adherence to the rules for installing thermal insulation.
Expanded clay: natural and environmentally friendly
This free-flowing, porous and fairly light building material differs from its counterparts in that it is based on special clay rocks with a quartz content. According to the size and geometry of granules, expanded clay is divided into:
- gravel (its granules are elongated);
- crushed stone (with particles in the form of acute-angled cubes);
- sand (with granules, the size of which does not exceed five millimeters).
The quality of expanded clay determines the bulk density, bulk density, porosity and strength. It is believed that more pores provide a better heat-saving function of the insulation.
Describing the operational advantages of expanded clay, one should highlight:
- high capacity for thermal insulation (even a small layer of expanded clay under the floor can raise the level of thermal insulation to a new quality level);
- light weight (due to this parameter, expanded clay insulation can be used at all stages of construction);
- enviable soundproofing (this parameter is extremely important for housing construction);
- non-susceptibility to decay, damage by rodents, fungus and mold);
- strength and durability (expanded clay is chemically inert, resistant to mechanical and thermal damage);
- flowability (that is, the ability to fill with such a heater space that has any shape and volume);
- environmental safety (this is an environmentally friendly material without toxic impurities);
- water resistance (even if moisture gets into the expanded clay layer, its granules, due to the ventilated gaps, will act no worse than high-quality drainage);
- affordable price.
This inexpensive free-flowing insulation can be used to improve the qualities of walls and floors, pitched roofs and basements. Thermal insulation of floors (and any other elements) of a residential building with expanded clay requires strict adherence to technologies.
1. We clean the floor.
2. We expose beacons around the perimeter of the room.
3. Pour a layer of expanded clay (at least 150 mm thick) onto the sand layer.
4. Level the surface with a fishing line.
5. We cover the expanded clay insulation with a waterproofing film.
6. Carefully fill in the concrete solution.
7. Regularly wet the surface with water for three to four weeks to prevent cracking.
Video: What is expanded clay? Its pros and cons
This material is suitable for those who choose environmental friendliness and naturalness, dream of achieving an extremely comfortable microclimate from the interior of the house, without fearing a slight decrease in the internal area due to a sufficiently thick expanded clay layer.
Minwata: practical and affordable
This soft coarse fiber material is a product of scrap metal and carbonaceous mineral alloys. Due to its durability, fire resistance and the ability to quickly install mineral wool (in slabs, rolls and mats of various sizes) has become incredibly popular in the construction business. It is especially appreciated for its breathability, which makes it an ideal insulation for a wooden house.
The operational advantages of mineral wool:
- fire resistance;
- high soundproofing ability;
- non-susceptibility to deformations during temperature extremes;
- acceptable price.
Disadvantages of mineral wool, which can be compensated for by correct handling of the insulation and adherence to all installation technologies:
- fragility;
- insufficient resistance to moisture;
- insufficient environmental friendliness.
Material with a loose structure. It does not trap steam, so its inner side must be vaporized with a layer of foamed polyethylene. It is important to carefully seal the seams formed at the border of the insulation fragments using ordinary metallized adhesive tape.
When insulating the floor with mineral wool, keep in mind that its height will rise by about 50 mm. And remember: you will achieve a high-quality result only if you follow the order of insulation. As an example, we suggest floor insulation system along the logs.
1. We tamp the soil.
2. We lay a layer of crushed stone, using bituminous mastic for its waterproofing.
3. We install brick posts (longitudinal interval - 2 m, transverse - 60 m), waterproof them
4. We lay wooden logs.
5. At the bottom of each log we fix a windproof layer (first a metal mesh, then a windproof film).
6. We put mineral wool on the foil between the logs.
7. Protect the insulation with a vapor barrier.
8. We seal the joints between the sheets.
9. We lay the plank floor.
Video: What is mineral wool? Its pros and cons
Mineral wool is an inexpensive, sure and quick way to warm up a room. Unfortunately, using this material, you cannot exclude the risk of not only harmful vapors in your home, but also rodents. Mineral wool is best suited for outdoor insulation.
Expanded clay or mineral wool?
Both the one and the other material have a relatively inexpensive cost, they can boast of a fairly simple installation process and a decent quality of insulation, therefore, you should choose between expanded clay and mineral wool, focusing on specific construction conditions, technical and financial capabilities. A good solution is a combination of these materials, as they complement each other quite well.
The choice of insulation for the floor: mineral wool, expanded clay, expanded polystyrene?