Build Daily


October 07, 2016 23:18

Vermiculite insulation

In most cases, when it is put about the insulation materials used for thermal insulation of residential houses, first of all recall the mineral wool in a particular embodiment, expanded polystyrene, expanded clay.Few remember the vermiculite, but many - and not even know about its existence.

Vermiculite insulation

Vermiculite insulation

And it is in vain.Unjustly located on the "sidelines", vermiculite insulation of natural origin, in which the production is not being used not only harmful, but in general any chemical compounds.And, at the same time, its insulation and the performance of not only comparable, but in some cases seriously exceed those of other commonly used insulation.In a word, this material deserves to meet with him as closely as possible.

What is vermiculite, and what are its main characteristics

Article Contents

  • 1 What is vermiculite, and what are its main characteristics
  • 2 The use of vermiculite for insulating works
    • 2.1 Application of vermiculitein the form of fillings
      • 2.1.1 well.Thermal insulation of the roof structure
      • 2.1.2 b.Thermal insulation of ceilings
      • 2.1.3 in.Thermal insulation of cavity wall
      • 2.1.4 Insulation of chimneys
    • 2.2 The use of vermiculite as a component for building and finishing solutions
      • 2.2.1 well.Preparation of solutions for screed
      • 2.2.2 b.Preparation of mortars
      • 2.2.3 in.Production of "warm plasters»
        • Video: dignity «ThermoVer» warm plaster
    • 2.3 finished plates on the basis of vermiculite
      • 2.3.1 Video: visual assembly instructions vermiculite boards

Although vermiculite as heating material, relates to mineral, naturally occurring, beneficial properties, surprisingly, were recognized not so long ago.As the rock he was described only in the late XIX century, but it took nearly a century to the characteristic features of this mineral were put at the service of man.

In fact, natural vermiculite - a rock silicate class, group hydromica.From muscovite it differs high content of bound water in the crystal lattice and low interlaminar bond of the material.Thus, the total starting molecule, natural vermiculite include four "attached" thereto water molecules.

Fragment hydromica - raw material for the production of exfoliated vermiculite

fragment hydromica - raw material for the production of exfoliated vermiculite

Normally it is quite hard rock, high-density, reaching up to 2400 ÷ 2700 kg / m³, not amenable to abrasion, but it is easy to delaminate at the plate.Its melting temperature - about 1350 ° C.But it was seen and used an interesting feature of the mineral - if it is not to lead to melting and heated to temperatures of 900 ÷ 1000 ° C, the material is completely changing its crystal structure.Thin plates swell - increase in size in the 15 ÷ 25 times and become porous columns appendix species or even thin thread, with pronounced golden or silvery sheen.Apparently, hence the name adopted by the mineral - vermiculite, from the Latin «vermiculus», which literally means "worm".

The result is expanded vermiculite - exactly the material that later widely applied in various fields of construction, industry and agriculture.Vozduhonapolnennaya structure has a very low density - it is much lighter than water, and its specific gravity becomes just from 60 to 130 kg / m³.

При высокотемпературном обжиге кусочки слюды превращаются в слоистых "червяков"

When high-temperature roasting pieces of mica in turn layered «worms»

Currently, the production of exfoliated vermiculite supplied on an industrial basis.In our country there are rich deposits required mica rocks - in Murmansk, Chelyabinsk and Irkutsk regions, Krasnodar and Primorsky Krai.

production cycle consists in several stages.This raw material sorting, refining (removal of impurities ballast), split into a fine fraction and baking.The baking process takes a matter of minutes - and then expanded columns are stage crushing to the desired fraction with subsequent sorting, packaging and shipment to consumers.

Prepackaged expanded vermiculite

Prepackaged expanded vermiculite

issued on the vermiculite plants must meet certain standards, the entered GOST12865-67.Thus, it is divided into:

- major - grain size of 5 to 10 mm;

- average - from 0.6 to 5 mm.

- fine - grain up to 0.5 mm

Usually consumers supplied material three different grades - 200, 150 and 100, where the number of designated upper limit of the bulk density of the material (kg / m³).The very same density and, accordingly, vermiculite insulation quality depend on the size fractions.For example, without departing from the scope of GOST, manufacturing plants offer a material with the following parameters:

average grain size, mm average bulk density of material, kg / m³ average coefficient of thermal conductivity, W / m × °with
at a temperature of +25 ° C at a temperature of +100 ° C
0,5 130 0,056 0,062
1,0 up120 0,052 0,059
2,0 110 0,051 0,057
4,0 95 0,048 0,054
8,0 65 0,046 0,052

vermiculite is now widely used in construction has become, as it has a number of advantages:

  • low thermal conductivity allows the use of vermiculite as an effective thermal insulator building structures.According to these indicators, the material is comparable with other popular heaters, for example, mineral wool or polystyrene, but significantly exceeds them in its other characteristics.
  • Operating Temperature Range - is extremely wide.Thus, the vermiculite itself, and many materials of construction based on it can withstand freezing below -200 ° C and heated to 900 ÷ 1000 ° C.The very same material - completely non-flammable and contains no additives, which may contribute to the spread of fire or combustion.When vermiculite is heated it does not emit any gases harmful to the human respiratory.These qualities are used to create an effective fire barriers or protection of metal structures of buildings.
One of the objectives of vermiculite - fire protection of metal structures

One of the objectives of vermiculite - fire protection of metal structures

  • Severe granulated and at the same time - a layered structure of vermiculite becomes an excellent soundproofing barrier.And air, and impact noises are damped in the thickness of the material, design and construction (wall or ceiling), insulated with vermiculite or made based on it, will not transfer "membrane", extends further sound waves.Sound absorption coefficient at a frequency of 1 kHz reaches from 0.56 (for a material with a minimum fraction of 0.5 mm) to 0.7 ÷ 0.8 (with a fraction of 4 ÷ 8 mm).
  • Although layered and seemingly unstable structure of vermiculite grains are highly durable.So, if you compare it with other exfoliated material - perlite, vermiculite is not afraid to transportation, vibration, he does not shrink, do not split up while on fines, not dusty.
  • material is chemically resistant and totally inert - it is without any loss of its qualities is able to withstand the impact of all known acids, alkalis, organic solvents or other fluids used in construction.
  • a very special property of the material - its pronounced absorption capacity and the highest water absorption.So, vermiculite is able to absorb the amount of water, by weight exceeding five times its own weight.This, of course, can be attributed to shortcomings of the material.However, vermiculite is as easy and gives moisture to the atmosphere, absolutely without losing its properties.

way, the absorbent quality vermiculite actively used for filtration systems to clean the soil and water from oil stains and other similar purposes.

advantage can be considered that in the insulation layer of vermiculite is formed condensate never drops - water soaks into the porous structure, and with the normalization of conditions moisture freely evaporate.Thus, the material helps to maintain optimal indoor temperature and humidity balance.However, this feature should be taken into account when planning the insulation material of building structures.

  • material has the highest biological stability.Despite the porous structure and a pronounced water absorption, it never decomposes, it does not pass or rotting processes debate.Vermiculite does not become a breeding ground for any form of life - it does not appear foci of mold, do not start the nest insects, rodents bypass his party.
  • material does not cause allergic reactions, even in people who are prone to such displays.Studies show that vermiculite is even able to reflect a certain part of the spectrum of radiation.
  • material is not subject to "aging" - with time he does not lose its specific qualities, nor under the influence of moisture or under the influence of extremely low or high temperatures.
  • Finally, he expanded vermiculite has excellent flowability.When filling them cavities in building constructions, it is able to completely fill the entire volume without leaving air voids.

a suspended material shortcomings can be attributed only two positions:

  • already mentioned the high hygroscopic material.When using vermiculite in particulate form must provide reliable waterproofing and the possibility of free evaporation of moisture.This is achieved by placing the correct vapor barrier and vapor-permeable membrane diffuse.
  • relatively high cost of the material.So, the price of vermiculite several times higher than other bulk mineral wool insulation - expanded clay or perlite.The cost of one cubic meter of material can reach 6.5 ÷ 7 thousand rubles.This, of course, somewhat limits its widespread use for thermal insulation of private homes.However, the advantages of durability and vermiculite fully justify such costs.

The use of vermiculite for insulating works

vermiculite to provide the necessary thermal insulation characteristics of the building can be used in several different ways:

  • in particulate form - for filling cavities insulated structures.
  • As part of the special mortars.
  • in the form of ready-made building elements (panels) made of composite materials based on vermiculite.

Application of vermiculite in the form of fillings

One of the popular methods of application of vermiculite - a filling of cavities insulated structures.


roof structure The figure shows an exemplary diagram of insulation pitched roof, for example, in the construction of a residential attic.

Driving insulation pitched roof and ceiling of the attic with vermiculite

Driving insulation pitched roof and ceiling of the attic vermiculite

1 - rafters.

2 - layer vapor barrier film that prevents moisture from penetrating into the space layer of insulation.

3 - inner lining rays and ceiling of the attic.

4 - frame construction - a crate for further roof decking.

5 - formed in the cavity is filled with dry vermiculite.

6 - on top of a heater was covered windscreen - diffusive membrane, preventing weathered loose vermiculite and a direct hit on it the water, but do not prevent the evaporation of moisture.

7 - then, on top of the membrane is installed kontrobreshetka, flooring made of roofing material.

b.Thermal insulation of ceilings

Driving insulation slabs, in principle, similar.

Warming of vermiculite attic floor

Warming vermiculite attic floor

On hemmed "rough" between the ceiling joists laid reliable waterproofing material, with the mandatory overlap webs and sealing joints .. mounted batten system (LAS) for subsequent floor attic floor.

Then, a cavity backfilled with dry vermiculite.Usually it is sufficient in the layer 100 ÷ 150 mm.

Top on the beams and joists attached diffuse membrane is laid and then (if necessary) the boardwalk or plywood flooring.

By providing ventilation of the attic (attic) in a thermal insulation layer moisture to accumulate will not - it will have free access to evaporate into the atmosphere.

Since vermiculite is relatively expensive material, some owners use it with a mixture of sawdust.Typically used or the proportions of 1: 1 or 3: 2.Interestingly, in a mixture of vermiculite sawdust "adopt" its resistance to biological degradation - processes and decay in the packing of them will not be marked.This dry mixture can be prepared using a conventional mixer or building on a drill tip.

in.Thermal insulation of cavity wall

With the construction of the wall on technology, "the well of masonry," the space between the bricks filled with dry vermiculite fashionable.A similar approach can be applied with insulation frame walls.

Vermiculite can fill in the left cavity of multilayer brick and frame wall ...

Vermiculite can fall asleep in the left cavity of multilayer brick or frame walls ...

Filling is done in stages as the construction of load-bearing wall and the facing layer (plating frame construction), with easy tamper material.

Another option is the creation of "warm wall" - is filling the voids of building blocks.Insulating effect of such a structure increases dramatically increases performance noise abatement walls.

... Or they fill the void of building blocks

... or they fill voids

building blocks Wall, however, remains "breathable" - free paroobmen it is not broken.

Insulation of chimneys

important points when installing the furnace or boiler is always insulation chimneys passes through walls and ceilings.And this problem can be solved very effectively by using vermiculite.

Options insulated chimney passes through the ceiling using vermiculite

Options insulated chimney passes through the ceiling using vermiculite

One of the options - to set the metal box in the aisle seat.The resulting space between the pipe and the ceiling is filled with dry vermiculite - insulation and the chimney will be provided.

Another option - use of walk-through sleeves that are also inside filled with vermiculite.

The use of vermiculite as a component for building and finishing solutions

Warming of vermiculite in the form of dry filling - high performance, but still - a very expensive solution.Therefore, in practice, this private building material often used for making mortar - since they can significantly improve insulation performance.

well.Preparation of solutions for screed

If the floor is supposed to fill the screed, and at the same time, it requires additional insulation, it makes sense to use for this purpose a concrete solution to the inclusion of a significant proportion of the vermiculite.

Screed with vermiculite has a higher thermal insulation and sound absorption properties

Screed with vermiculite has a higher thermal insulation and sound absorption properties

standard Portland cement M400 is used for the preparation of such compounds, sand and vermiculite with a bulk density of 80 to 150 kg / m³, a fraction from 0.5 to 5 mm.