What is expanded clay and what is it used for in heating

When choosing insulation materials, you need to figure out what expanded clay is used for, how to work with it. Universal gravel fractions are used in construction, for decoration of the local area or garden. Lightweight clay-based material has good sound insulation and heat saving properties, therefore it is suitable for backfilling under a foundation or into a frame wall.

Production technology

Expanded clay is obtained from rocks of clay shale, fired at temperatures from 1200 to 1300 degrees. Melting technology produces rough brown granules with pores that look like gravel. Dry, wet, plastic and powder-plastic methods are used. One batch of products is completely manufactured in 40 minutes, after which it is cooled and calibrated to size. If necessary, the material is crushed.

Expanded clay grains, depending on their size, are divided into the following types:

• Gravel - has fractions of 5-10, 10-20 and 20-40 mm. The shape of the product is spherical, slightly swollen.
• Crushed stone - the size of fractions is similar to gravel. The difference lies in the angular shape that resembles a stone.
• Sand - fine grains from 5 mm in size.

Most often, round or oval expanded clay is produced.

Specifications and material properties

GOST 9757-90 specifies the characteristics of the material, depending on the density. This indicator ranges from 200 to 800 kg / m3. The brand is also determined by density. Other indicators are determined by the size of fractions and are presented in the table.

Technical parameters explain the properties of expanded clay:

• resistance to temperature extremes, fire (class NG) and freezing;
• environmental friendliness - thermal insulation does not rot, cake and does not deform;
• high indicators of strength, chemical inertness and resistance to acidic environment;
• the possibility of using as a decorative material and insulation;
• good performance of sound and heat insulation;
• light weight - provides ease of transportation.

The material reduces heat loss at home by 50-75%.

Advantages and disadvantages of expanded clay

Excellent performance characteristics make it possible to use expanded clay in landscape design, for construction and other works. The advantages of clay grains include:

• versatility - can be used for laying on the floor, roof or other structural elements;
• low thermal conductivity - due to the internal pores, the granules retain heat well;
• duration of operation - ceramics, subject to the rules of operation, retain their properties for 40-60 years;
• chemical inertness - clay balls are not destroyed when exposed to alkalis and acids;
• fire resistance - the material does not melt, does not burn;
• a decent indicator of sound insulation - by filling the pores with air, an effective obstacle to sound waves is created;
• resistance to low temperatures - balls with an integral shell structure are not subject to destruction during frost;
• biological resistance - rodents do not live in the insulation, mold and fungus do not appear;
• ecological purity - the clay product does not contain allergens, does not emit toxins when heated;
• ease of installation - due to flowability, fractions are stacked on a site of any configuration.

Builders note several disadvantages of expanded clay grains. The property of frost resistance is lost by granules with a damaged shell, and laying is complicated by the performance of waterproofing works.

Comparison of expanded clay and expanded polystyrene

To insulate the floor, you can purchase expanded clay or polystyrene at an inexpensive cost. Budget materials are similar in ease of installation, but have several differences:

• Moisture is removed from the porous balls, and the foam in a wet environment rots or turns black.
• In case of fires, the clay fractions do not burn, the foam sheet - releases toxic toxins.
• The porous structure allows the polyurethane foam to "breathe", like expanded clay, but also accelerates its ignition.
• Polyfoam, unlike expanded clay materials, does not insulate the screed - it is more difficult to lay it.

Extruded polystyrene foam is also a competitor to expanded clay, as builders note that a strong synthetic base is better than brittle clay. In general, the building materials are similar - they do not emit toxic chemical compounds, are suitable for rooms with a humid environment, are distinguished by biological stability, and resist combustion reactions. The differences between them are as follows:

• the possibility of painting the extruded profile with primers;
• scope - the roof, floor and external walls are insulated with expanded polystyrene, with expanded clay balls - the floor, floors and roof;
• susceptibility to mold formation - low vapor permeability excludes aeration of external walls with polystyrene foam heat protection;
• reduction of the usable area - in order to insulate the building with expanded clay, you will have to sacrifice 50 cm around its perimeter.

Styrofoam and polystyrene need to be cut out, and expanded clay granules simply spill out, which reduces the time of work.

Varieties of ceramic grains

The material is classified by grain size. Based on this, it is divided into 3 categories.

Sand

Granules no more than 5 mm in size, made by crushing large pieces of baked clay or burning the remnants of the initial raw materials. Fine-graded expanded clay can be used as a filler for ultra-lightweight concrete or cement mixture.

Gravel

Round grains 5-40 mm in size, produced by swelling a clay billet in a blast furnace. Due to the good performance of thermal insulation, it can be used as a heater or in the manufacture of concrete blocks.

Crushed stone

Elements with corners, large - from 5 to 40 mm. Production is carried out by crushing ceramic layers. The material is the filler required for lightweight concrete.

Features of the use of expanded clay granules in heating

Expanded clay can be used as an insulating building material for floors made of wood or concrete, attic, roof, ceiling, walls, interfloor structures. Granules can protect not only the house from heat loss, but also bath structures or foundations. It can be used in bulk or in the form of blocks.

Block making

The process involves the preparation of expanded clay concrete mixture from clay balls, cement, sand and plasticizer additives.The recipe should be counted on 1 cubic meter of solution. As a result, you will need:

• 230 kg of cement M400;
• 600 kg of quartz sand with fractions of 2-2.5 mm;
• 190 kg of water;
• 600-760 kg of expanded clay gravel with fractions of 5-10 mm.

The output is concrete M150, which is suitable for wall structures. If necessary, a 10% aqueous solution of bitumen mastic is added to the mixture.

For manual production of blocks, you will need a vibrating machine or concrete mixer, molds and shovels. The form can be made of boards, plywood or iron, cutting them into blocks of 19x18.8x39 cm or half-blocks of 9x18.8x39 cm.The technological process is carried out in stages in a well-ventilated room:

1. Solution preparation. Cement is poured into the concrete mixer and water is poured. The remaining components are added in portions.
2. Pouring the mixture into molds. It is carried out in portions, 2 shovels each. Each layer is spread and compacted.
3. Pre-drying. Containers with concrete dough are covered with metal lids and left for 24 hours.
4. Drying. Forms with expanded clay concrete are placed on wooden pallets outside with a gap of 2-3 cm. The full set of brand strength occurs after 28 days.

To prevent moisture from acting on the blocks, it is better to build a canopy.

Masonry mortar production

Laying of expanded clay concrete blocks is carried out on a cement-sand mixture, for which the following number of components will be needed:

• 1 part of cement grade M400;
• 3 parts of sand (river + quarry);
• 0.7 parts of water.

Plasticizers are used to improve the performance of the mixture and eliminate the risk of delamination. You can add 30-50 g of soap or dishwashing detergent to the batch.

Dry cooking technology. The advantage of the solution is the reduction in the time for mixing in a concrete mixer. All components are mixed with a mixer until smooth. The disadvantage of this method is the overrun: for 1 cubic meter of masonry, 40 kg of the composition are needed.

Wet cooking technology. The concrete dough is not harvested in advance, since the hardening process occurs in 1.5-2 hours. Manufacturing is carried out in a concrete mixer, where water is poured, and then dry components are gradually added. Almost before the end of mixing, add the remaining liquid and plasticizers.

The procedure for warming floors, walls, roofs and foundations

Construction expanded clay is distinguished by its durability, environmental friendliness, and the ability to effectively maintain a comfortable microclimate. For this reason, it is used for thermal insulation of all building elements.

Wall insulation expanded clay is carried out with a three-layer structure of a supporting element, backfill with compaction and impregnation with cement milk and decorative cladding. Before work takes into account the type of material:

• Aerated concrete. Thermal insulation measures are carried out after the construction of the house. An auxiliary wall is laid out, which, together with the main one, forms a "well". Granules are poured into it, tamped and soaked. To remove moisture from the inside, ventilation ducts are made.
• Frame construction. Insulation work is complicated by the technology of ramming, during which the load-bearing elements are damaged. Frame type buildings without compaction of granules can shrink over time.
• Log house The wood material cannot withstand the stress caused by the ceramic grains.

Cement milk is made on the basis of 3 parts of water and 1 part of Portland cement.

Pitched roof insulation granular expanded clay is rarely found in practice. To implement the technology, you will need:

1. Make a pallet for the material by stuffing boards on the bottom of the rafters.
2. Lay the film vapor barrier with an overlap. It will serve as a waterproofing layer at the same time.
3. Pour the ceramic granules evenly onto the foil.
4. Cover the thermal insulation with a membrane with vapor barrier properties.
5. Equip a counter grill for ventilation.
6. Attach the boards holding the roof on top of the counter batten.

At the last stage, the roofing is laid.

Floor insulation expanded clay is permissible in the country or in a country cottage. Bulk material is laid dry, wet or backfilled under a cement screed. For the effectiveness of thermal insulation, it is necessary to calculate how much expanded clay is needed on the floor of a certain square. Reliable protection against cold penetration is achieved at 40 cm of granules on wooden flooring and 30 cm on expanded clay concrete. For each interfloor space of a private building, you will need 20 cm (for wood) and 15 cm (for concrete).

Order insulation of the finished foundation loose expanded clay depends on the location of the layer.

Outdoor work begins with a preliminary excavation of the base and making a trench 80 cm wide. Further work includes:

1. Arrangement of waterproofing with a coating method, bitumen mastic or roll roofing material.
2. The organization of a drainage channel, remote from the foundation at a distance greater than its depth. Geotextiles are laid on the surface of the soil, crushed stone is poured and pipes with holes of 1-2 cm in diameter are laid.
3. Backfilling of expanded clay fractions. A plastic wrap is lined on the drain, on which dry material with medium-sized granules is poured. The height of the embankment is up to the soil level.
4. Installation of the blind area. The design will prevent the clay ball from getting wet and covered with silt.

At the last stage, formwork is made at a height of 10-15 cm, reinforcement is installed and concrete is poured.

For thermal insulation of the basement, a protective brick wall is preliminarily constructed, removing it 20-30 cm from the upper edge of the foundation. After laying, expanded clay is poured, and a roll of moisture-proof material is laid on top of it.

The underfloor is insulated by filling the space or pre-made formwork. Polyethylene waterproofing must be installed at the bottom of the cavity. Clay fractions are poured so that there are no gaps between them. A sub-floor is placed on top of the loose expanded clay. It is allowed to pour concrete over the reinforcement.

To maintain the temperature of the coolant in the pipes and reduce heating costs, a "pillow" of granules is filled. It is also made by mixtures of bituminous solution with expanded clay gravel. The insulation should protrude 20 cm or more above the pipes. The convex part is covered with a polymer film, the side parts of which overlap the expanded clay by 10 cm.

Calculation of expanded clay

The calculation of the thickness of the insulation layer is made for the correct choice of material. The type of construction is taken into account in mathematical calculations.

The amount of expanded clay for walls

It is necessary to calculate the indicator of the thickness of thermal protection taking into account:

• thermal conductivity coefficient - 0.17 W / mK;
• the minimum thickness of the backfill is 20 cm;
• thermal resistance - according to the formula R = wall thickness / KTS (thermal conductivity).

According to SNiP on March 22, 2003, the climatic conditions of the area are taken into account.

Counting the amount of expanded clay for the floor

Calculations will help you find out the amount of material for backfilling under the screed and are made as follows:

1. With a standard layer thickness of 1 cm per square meter of the room, 0.01 m3 of granules is needed. In liters, the value is 10 l / m2.
2. Counting the amount of material according to the formula V = S x R, where V is the amount of building material, S is the floor area, R is the cost per square.

The larger the expanded clay layer, the more effective the heat protection.

Calculation of the material for the roof

When calculating the insulation material, the formula V = S x h x K is taken into account, according to which:

• V is the volume of clay fractions;
• S - area to be insulated;
• H is the thickness of the insulation;
• K is the shrinkage factor. For a flat roof, it is 1.2, for a pitched roof - 1.1.

Manufacturers supply bulk material in bags, where the volume is indicated in liters. 1 cubic meter is equal to 1000 liters, so the final result must be multiplied by 1000 and divided by liters in a bag.

Expanded clay is very popular as a high-quality insulation for the foundation, walls, floor and roof. The reason for using the material is ease of installation, excellent thermal insulation properties and inexpensive cost. Before starting work, it is necessary to calculate the volume of granules and select a technology.