Gas block or foam block: what is the difference and which is better?

The modern market is literally enslaved by such building materials as foam block and gas block. Many consumers are convinced that these names belong to the same product with their pros and cons. But in fact, these are different building materials, which have quite a lot of differences. Today we will figure out how they differ from each other and determine which is better - a gas block or a foam block.

Foam concrete, aerated concrete and foam concrete blocks are in great demand today. Houses built from them are very common. The demand for such building materials is due to their affordable cost and good performance characteristics. In addition, it should be noted that from the listed blocks it is possible to build not only residential buildings, but also various outbuildings.

Foam block is a very popular material that is in enviable demand among modern consumers. Quite stable and durable buildings are obtained from it, the construction of which can be coped with in the shortest possible time. It is easy to work with a foam block - for this it is not at all necessary to have a special education or extensive experience in construction.

Most people looking to build a house or outbuilding choose foam concrete blocks because of their low cost. Moreover, some users make this material with their own hands - the recipe for making foam blocks is very simple and straightforward, you just need to adhere to the correct proportions.

The advantages of foam concrete blocks are many, as well as disadvantages.

First, let's look at what these building materials are good for:

• The foam block is distinguished by low thermal conductivity. Thanks to them, very warm and cozy houses are obtained from this building material, which, at times, do not need additional insulation.
• Such materials are lightweight, so working with them is not laborious. Moreover, the master can cope with many processes alone, without the involvement of assistants.
• From the above advantages of foam blocks, another important plus follows - due to their low weight, foam block structures do not give impressive loads on the foundation structure.
• Buildings from a foam block can boast of good soundproofing qualities.

• The foam block is a material with a large volume, therefore, all kinds of buildings from it are made quickly.
• Another significant advantage of foam blocks is that they are inexpensive. Most consumers can afford to purchase these building materials.
• It is impossible not to mention that foam blocks are a very malleable material. If required, they can be filed or cut with a hacksaw.
• As a rule, foam blocks are environmentally friendly. They do not harm the health of the household. Of course, during the manufacture of these materials, synthetic components are used, but their content is too small to harm a person.

• The foam block is a material that boasts a long service life. Moreover, over the years, foam block buildings do not lose their positive qualities.
• This building material is not afraid of fire.It neither supports the flame, nor does it ignite itself.
• Many users mistakenly believe that only simple and monotonous constructions can be made from foam blocks. In fact, this is not the case. If the owners have such a desire, the foam block house can be made very original and fashionable.
• By itself, the foam block does not require mandatory decorative finishing. Of course, it will be more protected if it is covered with plaster or any other suitable material, but this is not a primary need.

However, not everything is so rosy - the given building material also has significant drawbacks, which you also need to familiarize yourself with:

• A foam block is a material that has a porous structure. Due to this fact, such products become more fragile, especially at the edges. For this reason, it is necessary to transport and carry foam blocks very carefully so as not to accidentally damage them.
• As mentioned above, it is not necessary to trim foam block structures, but it is better to do this. Firstly, in this way you will protect the material from aggressive external influences, and secondly, the construction will look much more attractive. But here you can face one common problem - for finishing foam blocks, you need to select special paints / plasters that are designed for foam concrete bases.

• Foam concrete blocks require reinforcement. Typically, fittings are installed at the joints of materials. If you do not supplement the structure with a reliable seismic belt, then you will not be able to build high-quality floors and install the same strong rafter structure.
• One of the main disadvantages of using foam blocks is that the modern market is literally overwhelmed with low-quality counterfeits made in clandestine conditions. Such materials are often made out of proportion, which leads to their increased fragility.
• If you want to make a residential building out of foam concrete elements, then you need to take into account the fact that it is permissible to start such work only after a scrupulous number of calculations. For example, you will need to determine the thickness of the walls of an erection, taking into account all the loads.
• For structures made of foam concrete, it is required to construct special foundations of the form-generating type.
• Some subtypes of foam blocks do not differ in the correct geometry. Often, during construction work, they have to be polished and cut for a long time and meticulously so that the same floors or walls turn out to be even and neat.

There are a number of subtypes of modern foam concrete blocks.

They are divided by purpose:

• Structural. Instances of this type are designed for heavy loads. They are often used for the construction of multi-storey buildings. Large-sized structures made of foam blocks are most often insulated, since this material is characterized by considerable thermal conductivity.
• Heat insulating. These types of foam concrete blocks are very different from the construction options. They are non-conductive, so the dwellings built with them are very warm. But thermal insulation blocks cannot be called high-strength. Usually they are used only as an additional layer in the construction of residential buildings.
• Structural and thermal insulation. These subtypes of foam blocks are considered universal. They have collected in themselves excellent strength properties, as well as good thermal insulation properties. Such materials are perfect for the construction of load-bearing walls or conventional partitions. Very often, baths or houses of small height are built from such blocks.

Such materials also differ in the manufacturing method:

• Molded (cassette). The name of such foam blocks speaks for itself.During their manufacture, special forms are used, closed with partitions. This method of production is considered to be the most economical. However, molded parts have one drawback - the dimensions of the finished foam concrete blocks are inaccurate and poorly calibrated.
• Rifled. The given foam blocks are made from a ready-made solution, which is cut into separate parts using a special steel string. These materials can boast of correct and neat angles. In addition, they are geometrically accurate.

Different designs are made from foam concrete blocks.

Depending on the specific purpose, one or another of the following is used:

• Wall. These foam blocks are more common than others. They are often referred to in suburban construction. This can be not only the construction of a private residential building, but also any backyard structure.
• Partitional. The second most in demand are partition foam blocks. They are thin enough - 100-150 mm. They are used to build strong and durable partitions in the inner part of the building. Due to their thickness, the baffle blocks can be cut without problems if required. Thanks to this distinctive feature, experienced craftsmen make beautiful arched structures from such blocks.

• Special purpose. In the manufacture of special trays, foam concrete blocks for special purposes are usually used. These elements are usually fitted with reinforcement.
• Reinforced. Such foam blocks are parts made of foam concrete, reinforced with a steel frame. Most often, reinforced blocks are used as lintels instead of standard reinforced concrete elements.
• Non-standard. There are also special non-standard foam blocks. They are made specifically for customers' orders.

Foam blocks are available in different sizes.

Materials intended for masonry with glue are made with the following dimensions:

• length: 188 mm width: 300 (mm), height: 588 (mm);
• 188 mm x 250 mm x 588 mm;
• 288 mm x 200 mm x 588 mm;
• 188 mm x 200 mm x 388 mm;
• 288 mm x 250 mm x 488 mm;
• 144 mm x 300 mm x 588 mm;
• 119 mm x 250 mm x 588 mm;
• 88 mm x 300 mm x 588 mm;
• 88 mm x 250 mm x 588 mm;
• 88 mm x 200 mm x 388 mm.

As for foam concrete blocks intended for laying on cement, their dimensions can be as follows:

• length 198 mm, width: 295 mm, height: 598 mm;
• 198 mm x 245 mm x 598 mm;
• 298 mm x 195 mm x 598 mm;
• 198 mm x 195 mm x 398 mm;
• 298 mm x 245 mm x 298 mm;
• 98 mm x 295 mm x 598 mm;
• 98 mm x 245 mm x 598 mm;
• 98 mm x 195 mm x 398 mm.

The main "competitor" of foam concrete is such a building material as aerated concrete. Many consumers also turn to him who want to build a house or any outbuilding on the site. This popular product, like the foam block, has its own strengths and weaknesses.

Let's start with the good things - consider the advantages of aerated concrete blocks:

• This building material is distinguished by its high density, which can be from 400 to 1200 kg / m3. If you use high-quality wall material with a low specific gravity, then you can spend quite a bit of time on the construction of a particular structure.
• Aerated concrete blocks are moisture resistant. Even in conditions of air humidity of 60%, the rate of gas blocks will be about 5%. If the humidity level reaches 96%, then it can reach 8%.

• Another significant advantage of aerated concrete is its fire safety, as is the case with foam blocks. This material can withstand even extremely high temperatures without any obstacles. In addition, the gas block does not support combustion.
• Aerated concrete blocks are not afraid of very low temperature values. Due to this quality, it is permissible to use such materials even in harsh climatic conditions.
• This building material is not afraid of biological effects.Aerated concrete does not need to be additionally treated with protective compounds or antiseptic agents, like, for example, wood.
• This building material is durable. Buildings made of aerated concrete can last for 100 or more years.

• Aerated concrete is environmentally friendly. It contains no dangerous toxins that have a negative impact on human health. Only wood can compete with aerated concrete blocks for environmental friendliness.
• Like foam concrete, aerated concrete has good soundproofing qualities. By building a wall of this material with a thickness of 40 cm, you can not worry about the noise coming from the street.
• Another advantage of aerated concrete is that it has good thermal insulation properties. Houses made of this material do not need to be additionally insulated in many cases. At the same time, a comfortable microclimate is always maintained inside such a dwelling.

• The undoubted advantage of aerated concrete is the level of its strength. If it is properly reinforced, then a large house with three floors can be erected.
• This building material is distinguished by its ease of processing. It can be trimmed or sawed if required. The block can be easily given one or another size and shape. However, here it is worth considering one nuance: dowels are very poorly held in aerated concrete walls, therefore it is recommended to use other fasteners - self-tapping screws.
• A little cement is used for the production of aerated concrete.
• This building material is inexpensive, because raw materials of natural origin are used in its production - quartz sand, cement, lime.

• Aerated concrete is lightweight, so working with it is not too laborious. Its structure is also cellular, so you can easily move such blocks without resorting to the help of a crane.
• Aerated concrete is a versatile material that is used not only in the construction of houses or outbuildings, but also in the manufacture of fireplaces, steps or fences. This advantage is due to the pliability of this material - it can be given almost any shape.
• This material also has excellent vapor and air permeability characteristics. The coefficient of these qualities for foam concrete is practically the same as for wood. According to experts, air circulation and the level of humidity in a house made of such material will be naturally regulated, forming a comfortable microclimate.
• Currently, aerated concrete blocks are manufactured at factories where strict quality control of products is carried out at each stage of production.

Aerated concrete blocks are not ideal, as are foam concrete options.

They have their own disadvantages:

• This material is characterized by high hygroscopicity.
• If the foundation of the building was erected with any violations, then gas-block buildings can give noticeable cracks. Moreover, these defects arise not only along the lines of the masonry, but also on the gas blocks themselves. Microscopic cracks appear on this building material in just 2-4 years.
• Yes, aerated concrete blocks are responsible for the formation of the ideal level of humidity in the room, but over time, these materials begin to accumulate excess moisture in their structure. This leads to dampness and delamination of the blocks.
• Aerated concrete does not have the highest price, but it is higher than the cost of foam blocks.
• Gas blocks cannot boast of sufficient thermal insulation characteristics, especially when compared with foam blocks.

There are several types of aerated concrete.

Each species has its own markings.

• D350. This brand is considered one of the most rare. This is due to the fact that such blocks are fragile. They can only be installed as seals. The strength level of D350 is 0.7-1.0 MPa.
• D400. This type of aerated concrete is more durable and stronger.This property of this material can range from 1 to 1.5 MPa. Such materials are used both as thermal insulation and as openings in multi-storey buildings.
• D500. The strength level of this building material is 2-3 MPa. Typically, such blocks are used in the construction of monolithic buildings. They are also suitable for low-rise construction.
• D600. High-strength aerated concrete blocks have this marking. Their strength level can be 2.4-4.5 MPa. Due to its performance characteristics, aerated concrete of the D600 brand can be used for the construction of buildings with ventilated facades.

The brand of aerated concrete affects its final cost.

Aerated concrete blocks also differ in their shapes:

• rectangular elements are used to design partitions and load-bearing walls;
• reinforced parts are usually bought for the manufacture of ceilings;
• T-shaped blocks are intended for floors;
• for openings, U-shaped aerated concrete blocks are used;
• there are also arc-like options for aerated concrete blocks.

Gas blocks, like foam blocks, are heat-insulating, structural and structural-heat insulating. As for the size of aerated concrete, a lot depends on their shape.

Simple rectangular elements have the following dimensions:

• length - 625 mm;
• width - 100 mm, 150 mm, 200 mm, 240 mm, 300 mm, 400 mm;
• height - 250 mm.

U-shaped blocks are produced with the following dimensional parameters:

• length - 600 mm;
• width - 200 mm, 240 mm, 300 mm, 400 mm;
• height - 250 mm.

Foam concrete and aerated concrete are made using different technologies. Let's consider them in more detail.

Aerated concrete blocks are produced as follows:

• First, the necessary materials are prepared in the right proportions (these include sand, lime and cement). When dry, they are mixed using a special technique for 4-5 minutes. After that, a suspension of aluminum powder is added to the mixed composition, the basis of which is water.
• In the course of mixing, lime reacts with aluminum. This produces hydrogen. Due to strong gas formation, air bubbles form in the composition. They are evenly distributed throughout the solution.
• After that, the finished composition is poured into a mold. It should be preheated to the 40 degree mark. Pouring is done at ¼ of the volume of the container.
• When the composition is sent to the molds, they are transferred to a special chamber, where further pore formation of the material is carried out. As a result, the volume of the resulting mass begins to grow gradually and acquires strength properties. In order to activate the desired reactions in the solution, as well as for its optimal distribution in the form, they turn to vibrational action.
• When the resulting composition reaches preliminary hardening, any irregularities must be removed from its surface. This is done with wire strings.
• Further, the composition is taken out of the chamber and transferred to the cutting line.
• The next step in the manufacture of gas blocks will be to send them to an autoclave.

Often, aerated concrete slabs are marked with the designation AGB (meaning autoclaved material). At the same time, the autoclave itself is a kind of "pressure cooker" of impressive dimensions. Under its conditions, a pressure of 12 atm is injected, and then maintained. As for the temperature, it should be 85-190 degrees. In this setting, aerated concrete slabs are prepared within 12 hours.

When the blocks are completely cooked in an autoclave, they are divided additionally, since during preparation in some places they can connect with each other. After that, these materials are placed in a special heat-shrinkable material or polyethylene.

Aerated concrete is produced without the use of an autoclave. In this case, the hardening of the composition takes place in natural conditions - in this case, special equipment does not need to be used.

Foam concrete is made a little easier and easier. There are 2 ways of its production - cassette and sawing.

The cassette method involves pouring the solution into special forms.

The technology, called sawing, involves pouring the solution into one large container, after which it is expected to harden and further cutting into separate elements of the required dimensions is carried out.

For the manufacture of foam concrete blocks, cement of the M400 and M500 grades, clean sand without clay, a foaming agent, potassium chloride and, of course, water are used.

If you decide to use foam concrete or aerated concrete for building a house, then there are a number of specific requirements you should consider when using these materials.

• The foundation should be as strong as possible, despite the fact that such block materials have a low weight and a porous structure.
• The horizontal surface of the foundation structure must be covered with waterproofing.
• Drilling holes, cutting, slitting blocks with cells is carried out in the same way. A hand saw is used for cutting, holes are drilled with a drill and drill bits.
• Foam block materials can be laid on cement or special glue. Aerated concrete is mounted only on glue.
• Stop building the house if necessary. Preserve the property for the winter. During this time, there will be nothing to foam concrete walls, but aerated concrete should be covered with a waterproof film.
• Pay attention to the retention of the fasteners on both materials. It is advisable to use special screws, anchors and hardware.
• For cladding such block facades, you need to use special plasters, lining, siding, stone and other similar materials. There are no serious restrictions.
• Sometimes it is not necessary to insulate houses from porous blocks. If this is necessary, then you need to turn to insulation. It is recommended to use basalt wool.
• Not all plaster is suitable for finishing such block bases. For foam blocks and gas blocks, it is necessary to purchase compositions that will maintain their vapor permeability.

To understand which material is better, it is necessary to compare the foam block and the gas block in several parameters:

• Structure. Foam blocks have large and closed cells with poor water absorption. Their surface is gray. Gas silicate blocks have smaller pores. They have weaker thermal insulation and require additional finishing.
• Strength characteristics. Aerated concrete blocks are less dense (200-600 kg / cubic meter) than foam concrete blocks (300-1600 kg / cubic meter). Despite this, foam concrete is inferior to aerated concrete, since its structure is heterogeneous.
• Frost resistance. Autoclaved aerated concrete blocks are more frost-resistant and vapor-permeable than other similar materials.
• Features of the application. Cellular foam concrete is used in low-rise construction. It is also used in the construction of monolithic buildings (here it is used as an additional insulating layer). Aerated concrete materials are used as the main structural and thermal insulation materials. They are used to build houses of the most varied complexity.

• Production. It is much easier to run into low-quality foam concrete than bad aerated concrete. This is due to the fact that the former is often made in artisanal conditions, and the process of creating aerated concrete materials is more high-tech and is often carried out in a factory.
• Price. Price is the most obvious difference between foam blocks and gas blocks. The latter will cost more, since foam concrete blocks are made from cheap raw materials.
• Soundproofing. Foam concrete blocks have better soundproofing characteristics than aerated concrete options.
• Life time. Foam concrete on average lasts no more than 35 years, and aerated concrete - more than 60 years. This is another important difference to consider when choosing the right material.
• Shrinkage. The degree of shrinkage of foam blocks is greater than this parameter of gas silicate materials. It is 2.4 (and aerated concrete - 0.6).

It is not so difficult to distinguish aerated concrete from aerated concrete. It is enough to pay attention to their surfaces. The foam blocks are smooth, and the gas blocks are slightly rough. To say with certainty which building material is better is already more difficult, since both have their pros and cons. However, it is necessary to take into account the opinion of experts who argue that after all, gas blocks are stronger, and their frost-resistant characteristics are better. As for foam blocks, they are warmer and cheaper.

We must not forget that low-quality foam concrete is more common than second-class aerated concrete, as evidenced by the reviews of many consumers. Be that as it may, the choice is up to the buyer. It is important to decide in advance for yourself exactly what qualities you are looking for in these building materials before you go shopping.

Comparison of the gas block with the foam block is in the next video.