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Thermal insulation polyurethane foam (PPU)


The issue of insulation of residential buildings is relevant in almost all regions of Russia. Polyurethane foam spraying is an effective solution to the problem. This insulation is a two-component composition.

The coefficient of thermal conductivity of the material is very low, it is only 0.021 W / m 2 K. The layer of foamed polyurethane foam with a thickness of 0.05 m according to the properties of thermal conductivity corresponds to brickwork of 1.6 m. In addition, the material is very light. All this explains its wide popularity among builders of different profiles.

Scope of polyurethane foam

1. The construction of sandwich structures at industrial and civil facilities.

2. The creation of a soundproof layer in wagons and aircraft.

3. Thermal insulation by spraying polyurethane foam on external walls, window openings, internal roofs, doors and other structural elements.

4. Insulation of pipelines of cold and hot water supply.

Polyurethane foam is also used in the automotive industry, electrical engineering and many other fields.

Advantages of polyurethane foam insulation

1. Low coefficient of heat loss by the building.

2. Resistance to negative environmental factors.

3. Excellent long-term adhesion with all types of cellular concrete, brick and drywall.

4. No need to fix the insulation with fasteners.

5. Polyurethane foam has excellent hydrophobicity.

6. The possibility of a monolithic distribution of the material, that is, without visible seams.

7. Warming with polyurethane foam by spraying does not require periodic recovery. This greatly saves labor.

8. The material consists of cells that allow it to “breathe”.

Disadvantages of polyurethane foam insulation

1. The manufacturers declared service life of the material is 15-20 years. But already in the fifth year of operation, polyurethane foam can lose up to 30% of its thermal insulation properties. This phenomenon is not so noticeable in conditions of constant low temperatures.

2. Equipment for spraying polyurethane foam is quite expensive.

3. The material has low fire safety.

It can be concluded that the advantages of the material are much greater than the disadvantages.

Polyurethane foam spraying technology

Before making insulation by spraying polyurethane foam, you need to prepare the treated surface. To do this, clean it from contamination and dry well. It is important to remove all rust from metals and degrease them. Aluminum requires a mandatory primer coating with a high degree of adhesion, this will help increase the adhesion of the insulation to the surface.

An important place in the technological process of spraying is the temperature of the environment and components. To obtain a highly effective layer, it is necessary that the composition is from 10 to 25 ° C. Optimal for the room is a temperature above +5 ° C. Work in a colder environment can only be done with a solution warmed up to the desired state.

Polyurethane foam, which is almost always positive, is sprayed at a pressure above 100 atmospheres. About two seconds after spraying, a foaming reaction occurs, followed by solidification of the composition. The resulting layer provides excellent thermal and waterproofing.

Polyurethane foam spraying steps

1. Mixing all components of the composition. As a rule, mixtures of reagents, fire fighting compounds, isocyanate and fixative are combined. The last two components must be premixed separately and filtered off when a precipitate forms.

2. Spraying with polyurethane foam from a special spray gun using a compressor (foam generator).

3. Repeated surface treatment (if necessary).

The average cost of spraying polyurethane foam in Russia

As you know, prices for various goods and services may vary in the regions of the country. This also applies to polyurethane foam spraying. The cost of spraying 1 m 2 depends on the thickness of the layer and the volume of the order. The larger the cultivated area, the lower the price per square meter.

On average, for small volumes of work, that is, up to 200 m 2, spraying with polyurethane foam costs 550-630 rubles per 1 m 2. With an increase in the area for processing, the price per square meter decreases to about 500-600 rubles.

When making an approximate estimate for spraying with polyurethane foam, the price will also depend on the height of the walls. Typically, such markups are expressed as a percentage of the cost of services. For example, processing walls with a height of more than 3 m will cost 10-20% more, and basement with low ceilings - 20%.

The final cost of spraying polyurethane foam is calculated by specialists of companies providing such services. Workers always see the most vulnerable places for heat to escape from the room. Therefore, experts will certainly suggest treating these surfaces several times.

Today, you can work with polyurethane foam yourself. To do this, you need to have special equipment and basic knowledge about sprayed components. Work is always best done together.

DIY polyurethane foam spraying equipment

Construction stores sell disposable kits for spraying polyurethane foam onto small areas. Most often, such sets consist of two cylinders. In one of them - a polyol with Freon 134, in the other - isocyanate.

The design of the equipment provides for the mixing of components after pressing the trigger of the gun. Hoses with compounds are connected to gearboxes. In tanks, pressure and temperature are constantly monitored. In case of violation of one of the parameters, the material will seize worse, which will lead to an increase in its consumption.

DIY equipment cost for spraying polyurethane foam

The distribution of portable installations for independent work with polyurethane foam is due to the fact that in private homes the area for insulation can be very small. Teams of professional workers with expensive equipment simply do not go to such facilities, since it is unprofitable. In other cases, small work will be very expensive due to the lengthy assembly of the plants. Disposable kits are designed for safe use by amateurs. On areas of less than 20 m 2 they are beneficial.

The average cost of a one-time installation is from 16 to 30 thousand rubles. It contains about 1 m 3 of polyurethane foam. The same volume of the composition purchased in a specialized company will cost more than 30 thousand rubles. The benefits of doing it yourself are obvious.

DIY polyurethane foam spraying

All work must be carried out in fine weather. High humidity in the street and indoors at this time can spoil a little polyurethane foam. Do-it-yourself spraying must be done in several layers. This is one of the main principles of work.

Polyurethane foam insulation by spraying begins with complex surfaces: chimneys, ventilation hatches and pipelines. At the same stage, you need to close all the joints that go out. The first layer is preferably applied with a thickness of approximately 14 mm. After it hardens, you can proceed to further work.

The second and third layers are applied to each other with a short time interval. It is optimal to carry out all work in one day. If this is not possible, then starting every next layer, you need to carefully prepare the surface. With proper planning of working time, insulation of a medium-sized private house can be carried out in 2-3 days.

The most effective sound and heat insulation is considered to be a structure consisting of three layers.

Advantages and disadvantages of self-spraying polyurethane foam

Spraying work is carried out by specialists with professional equipment quickly enough. All work takes 1-2 days. Independent spraying may take longer, because you need to carefully study the instructions and deal with the equipment.

Polyurethane foam, the self-spraying of which is beneficial only in small areas, freezes almost instantly, regardless of the design of the installation. This proves that there is no difference between professional and disposable designs.

Thus, in each case, the decision on independent or professional insulation of the house is made by the owners.

Polyurethane foam spraying reviews

Most owners of private houses and apartments are satisfied with the thermal insulation of polyurethane foam. This method of warming rooms is especially relevant for buildings with a large number of arches and other curved elements.

Polyurethane foam spraying, reviews of which are quite numerous, is popular for balconies and loggias. After correctly completed work in these parts of the apartments, it becomes so warm that you can go out in home clothes, even in winter.

Thus, spraying with polyurethane foam is an effective way of warming private houses and apartments.

Types of sprayed polyurethane foam and application technology

Polyurethane foam is obtained by mixing two components - diisocyanate and polyol. Both components are separately toxic, therefore work is carried out with respirators. When mixed, two toxic substances form a safe polymer - polyurethane - absolutely neutral, which does not react with any substances. Polyurethane foam after hardening is absolutely harmless and is often used in the food industry.

When two components are mixed, active gas formation occurs - mainly carbon dioxide is released. It turns out to be enclosed in the thinnest polyurethane shell, which gives high rates of thermal insulation (carbon dioxide does not conduct heat well).

The mixing of the two components takes place in a special gun under high pressure. To get perfect foam, the components must be heated to 45 ° C (there are heated supply hoses, and there are special heaters). Under pressure, in the form of very fine dust, the components are mixed in a gun and sprayed onto the surface, where they are foamed, and then harden. This is the insulation with polyurethane foam.

It adheres well to any dry surface.

To achieve the declared qualities of the material, diisocyanate and polyol must be supplied in equal proportions. Even a slight increase in one or another component negatively affects the characteristics of the material. Worse, if there is more diisocyanate, such a foam will quickly “sit down”, then collapse, lose its heat-insulating characteristics. If you overdo it with a polyol, the picture is a little better - the foam becomes brittle, but it performs its tasks, although it has a thermal conductivity higher than stated. This is one of the drawbacks of polyurethane foam insulation - the final result very much depends on the qualifications of the workers and the class of equipment used.

Mixing components in predetermined proportions is almost perfectly accurate using high-pressure units. Therefore, when choosing a company, you need to pay attention to the equipment that they have at their disposal - with low pressure installations, most likely you will get heterogeneous spraying with poor thermal insulation characteristics.

But different equipment is not everything. There are also different types of polyurethane foam by cell type and density:

  • Open-cell lightweight PPU. According to its characteristics (thermal conductivity) it is very similar to mineral wool, with the same main drawback - it is hygroscopic, and at the same time it costs much more than mineral wool. That is, when using lightweight polyurethane foam (density 9-11 kg / m 3), it will be necessary to ensure its hydro- and steam insulation from all sides, to organize a ventilated facade - to remove excess moisture. In pluses, you can record higher sound insulation (compared to mineral wool). It is used extremely rarely for insulation of external walls and roofs, as it simply does not cope with the assigned tasks - it gets wet and loses its thermal insulation properties. For all that, it costs more than mineral wool. But for the insulation of internal partitions and ceilings it is used successfully (in combination with all hydro / steam insulating layers), providing also good sound insulation.
  • Closed cell polyurethane foam. Regardless of density, it is not hygroscopic, it "adheres" very well to almost any surface, with the exception of polyethylene. There are the following types:
    • The average density is 28-32 kg / m 3. The standard solution when using sprayed thermal insulation on walls, ceilings, non-exploitable roofs. It provides good thermal insulation with a coefficient of thermal conductivity of 0.02-0.028 (for air it is 0.022, lower only for vacuum). The vapor permeability is average - 0.05 (comparable to wood).
    • Medium density to fill cavities. The characteristics are similar to those described above, but it expands more slowly, freezes only after complete foaming. It is used when installing laminated walls, roofs, etc.
    • PPU of high density - 40-80 kg / m 3. It is used for warming exploited roofs, under screed, in other places with high mechanical load. Due to the higher density, the thermal conductivity coefficient is slightly higher - 0.03-0.04, the vapor permeability is the same - 0.05.

Speaking of prices, the cheapest one is lightweight open-cell polyurethane foam. But if you add the need for a device of hydro- and vapor insulation, then in general the price of insulation will not be so low. At the same time, it is unrealistic to achieve perfect insulation anyway, and it may well turn out that this type of PPU insulation will be cold. So that you can navigate the prices, we give approximate prices for different types of PPU (material + work):

  • light with an open cell from $ 180 per cubic meter,
  • closed-cell medium density - from $ 650 per cubic meter.

Warming with polyurethane foam on wooden walls will not cause problems - they have the same coefficient of thermal conductivity

Closed-cell polyurethane foam, per cubic meter, is much more expensive, but it does not require any additional layers, except for the finish. Not afraid of water or steam, it has been fulfilling its tasks for a long time (more than 25 years). The exact price of insulation with foamed PPU depends on its density and layer thickness, the size of the sprayed surface. It is considered individually.

Advantages and disadvantages

Let's start with the advantages:

  • To date, polyurethane foam insulation is the most effective. This is due to the cellular structure of this insulation and carbon dioxide enclosed in the cells. Ideally, this system gives a coefficient of thermal conductivity of 0.02, which is even lower than that of air (0.022).
  • A continuous, seamless spraying that negates the presence of cold bridges, further increasing the efficiency of insulation.
  • The possibility of spraying on the surface of any, the most complex forms.
  • Low hygroscopicity. Along with warming, you improve the waterproofing characteristics of the surface. This property is used when warming foundations, wells and other similar structures.

When warming the foundation of the house with polyurethane foam, the problem of its waterproofing is simultaneously solved

As you can see, a decent list of advantages that contribute to the fact that thermal insulation with polyurethane foam is gradually becoming more and more popular. But there are disadvantages:

  • High price - 1.5-2 times higher than with mineral wool insulation. But if you calculate for the year of service, it will turn out no more expensive.
  • The end result is highly dependent on the equipment used and the pollen experience. Good results are achieved only with full adherence to technology.

Thermal insulation with polyurethane foam flooring in the attic

The main limiting factor in the spread of PPU insulation is the high price. Although, when compared with the cost of insulation with extruded polystyrene foam, the prices do not seem so high and this despite the fact that the sprayed thermal insulation is stacked several times faster, it gives a better result. In general, if you plan to warm your home, this technology is worth exploring.

Application conditions and surface preparation

Even with good adhesion, which is characterized by warming with polyurethane foam, surface preparation will not be superfluous. First of all, you need to remove everything that crumbles - and first of all, old paint. Oily spots are also subject to mandatory removal and neutralization. They should not be.

PPU is applied on dry, fat-free surfaces.

Everything that should not be covered with foam should be covered with polyethylene fixed to tape. It is necessary to fix it carefully, without gaps - it is difficult to tear off the foam.

When insulating the roof with polyurethane foam, there are two ways to apply thermal insulation. First - they make a permanent continuous crate, on which foam is poured. The second - make a temporary frame, consisting of two parallel planes.

If the exterior walls of the building are insulated with polyurethane foam, a finish is assumed. And after cleaning the surface, care must be taken that something can be strengthened - it will not work on foam. For this, most often, wooden or metal planks are stuffed onto the walls, to which the external finish is then attached. On this the preparation is completed. Но нанесение пенополиуретана возможно только на абсолютно сухую поверхность, при температуре выше +10°C. Других условий нет.

Процесс напыления

Если вы заключили договор с какой-то кампанией, в назначенное время приезжает микроавтобус. It has spraying equipment. For operation of the high-pressure apparatus, a voltage of 380 V is necessary. If you have only 220 V, a generator is usually started, which produces the required voltage. A low-pressure apparatus can operate from a 220 V network, but, as mentioned below, the quality of thermal insulation will be significantly worse.

Usually only hoses are pulled into the house or around the house, through which components for the formation of foam are fed into the gun. It's comfortable. Workers who spray thermal insulation are dressed in protective suits, wearing a respirator, gloves and goggles. A respirator is necessary, since the components of the foam are toxic before hardening, and everything else is necessary to protect the skin from the ingress of PPU, which is then impossible to tear off.

Foam is applied from the bottom up, in small portions. Pour everything, without passes, trying to prevent the formation of shells. As the foam expands, make sure that the layer thickness is not less than required. After the foam has hardened, the surplus can be cut off, but you can’t make up for the deficiency.

Parameters of sprayed insulation

It’s worth mentioning right away that, as for any other insulation, the walls of buildings are preferable to insulate from the outside. If you insulate from the inside, the outer wall will freeze. How many defrosting / freezing cycles it can withstand depends on the material, but rarely such a house will serve more than 10 years.

When insulating with polyurethane foam from the outside, a finishing external finish is required - the surface has a very unattractive appearance. But no problems with freezing walls, the building will last a long time.

There are no problems with the roof. Roofing materials are designed for repeated freezing, so that the roof can be insulated with polyurethane foam from the inside, spraying it directly on the "wrong side" of the roofing material or on the crate.

Sprayable thermal insulation can be applied to any surface, and the roof can be insulated from the inside

Outside, to insulate the house or from the inside sorted out. Now a little about the thickness of the layer. Warming with polyurethane foam is usually done with a large thickness. This is not due to the fact that small is not enough. Usually, just because of the thermal characteristics, a thickness of insulation of 2-3 cm is required, and at least 5 cm is made. This is so that under any conditions the dew point appears in the thickness of the insulation, and not in the wall material. Since PPU is non-hygroscopic, it cannot get wet, condensation simply does not occur, and excess moisture due to the vapor permeability of the material is removed naturally.

Varieties and details about PPU

The method of spraying can be applied to several types of insulation:

  • carbide-formaldehyde polystyrene - penoizol (KPF), which requires a foam generator. The composition is mixed with water, forming a foam, and when it hardens, it becomes like a mounting foam,
  • Ceramic liquid insulation in the form of a suspension, which is suitable for all types of surfaces (brick, concrete, wood, metal, plastic, etc.). Safe, tolerates coloring, wallpapering, plastering,
  • the filling foam, which is suitable for warming any room, is odorless, and after solidification takes a cellular structure and retains heat well. Durable and suitable for high-rise buildings.

Sprayed polyurethane insulation is a type of foam. Such gas-filled plastics are obtained in the process of foaming and subsequent solidification of certain liquid mixtures. The cells of the obtained substance are filled with carbon dioxide, air, sometimes other gases are used.

About 98% of the volume of this insulation is occupied by gas, only 2% accounts for solid matter. This circumstance determines the main feature of gas-filled plastics of this kind - low specific gravity.

Popular manufacturers and prices

The most popular manufacturers of spray insulation are the following:

  • SEALECTION for interior use
  • HEATLOK SOY, which can be used internally and externally,
  • Ecothermix 300 (for outdoor work with 92% closed cells) and Ecothermix 600 (for indoor work with open cells).

Approximate prices for external thermal insulation with a foam layer of 2.5 cm / m2 can reach up to 500 rubles, for a layer of 5 cm / m2 - up to 800-900 rubles. Internal thermal insulation requires a layer of at least 10 cm / m2 and will require approximately 500-600 rubles at a density of 10 kg / m3. On walls and foundations, costing will be close to internal insulation. The price also includes the cost of equipment and work equipment.


The most remarkable quality for the user is ease of transportation and economy. Polyurethane foam is stored in small metal containers that are light enough and quite convenient for transportation and storage. This material is absolutely not toxic, therefore it is safe for human health and pets.

This property of polyurethane foam is especially important when warming a room from the inside. Neither temperature changes, nor interactions with the liquid provoke this material to release harmful substances, so the whole process can be done with your own hands without resorting to the services of specialists.

Additional advantages

Sprayed thermal insulation absorbs noise well and has excellent waterproofing properties. This means that moisture will not accumulate in your walls, and fungus will not start. Both in the cold and warm season, the house will maintain a comfortable atmosphere in the desired temperature range.

Since the sprayed thermal insulation is applied in one layer, there are no joints and seams in the coating. This means that there will be no leakage of precious heat even in the most problematic areas.

Polyurethane foam contains various anticorrosive substances. Therefore, when applying polyurethane foam on metal surfaces, a layer is formed that retains heat and at the same time protects the metal from moisture and rust.

Polyurethane foam slowly ignites and quickly attenuates in the absence of oxygen. Therefore, the chances of it igniting are very small. If you want to reduce the probability of ignition to zero, you should treat the coating with a layer of special paint.

Types of application

The technology of thermal insulation with polyurethane foam allows for thermal insulation during the initial construction and overhaul of the building. PPU sprayed thermal insulation is widely used for insulation:

  • roofs of various buildings,
  • walls of industrial and residential buildings,
  • vegetable stores and refrigerated warehouses,
  • pipelines, technological tanks, non-residential premises.

Spray insulation can be carried out on surfaces such as reinforced concrete, aluminum, asbestos cement, concrete, composites and so on. Due to its properties, polyurethane foam adheres perfectly to any surface and completely fills any cracks and breaks.

Preparation for work

The process of warming is quite capable of making any host. Sprayed thermal insulation will require two components:

  • prepared mixture of blowing agents, polyester components, foam regulators and extinguishing agents,
  • a substance based on isocyanate.

The first ingredient is thoroughly shaken. Usually, a mixing mechanism is used for this, do-it-yourself work may not give the desired accuracy. Isocyanate is carefully checked for impurities. If they are found, the second ingredient is heated to 700 ° C and mixed. Before use, the mixture is filtered through a metal sieve. Components are used in a 1: 1 ratio.

It is important to remember that the ingredients should not be in contact with water, steam or moist air, foreign objects should not be allowed into them. Containers in which the components for insulation remain must be tightly closed.

All ingredients are best used in the short term, immediately after preparation.

Spraying equipment

The whole process of applying foam insulation is made by low pressure machines. In addition to machines, for work you will need:

  • protective glasses,
  • work clothes and shoes, rubber or cotton gloves,
  • additional equipment: gas mask, thermometer and respirator.

Surface preparation for application

Before you start spraying with foam, you should prepare the work surface. To do this, it is cleaned of dirt and wiped dry. On the surface there should be no cracks and dents with a diameter of more than 6 mm, otherwise the setting (adhesion) will be incomplete. If the day scheduled for work is raining or there is increased humidity, do not start applying foam.

Choose a dry, sunny day for work on which the temperature of the working surface does not exceed 30 ° C. If the surface is hot, the foam consumption will be higher than normal due to poor foaming.

How is the application

Of the two containers using a pump, a mixture is collected in a certain amount. After that, the dispensing gun, in which there is a nozzle, is filled with the mixture. The compressor pressurizes the gun to a specific value.

The components of the mixture are mixed and fall on the work surface. A thick foam forms, which cools and hardens fairly quickly. All equipment is equipped with electronic sensors that monitor the working pressure in the hoses and tanks, air temperature and more.

Work technology

Spraying should be in a liquid state. At low surface temperatures, a thin layer of foam is applied to it for insulation. Only after the hardening of the preliminary layer is complete, the process of insulation can be continued.

Polyurethane foam is first applied to hard-to-reach surface areas - ventilation holes, chimneys, complex wall sections and more. Each subsequent layer of foam is applied only after the previous layer has completely hardened. The standard thickness of the applied insulation is not more than 1.5 cm. For optimal insulation, it is necessary to apply at least three layers of foam.

Even if the area of ​​work is large, it is necessary to complete all the work in one day. If this condition has not been fulfilled, then by the beginning of the next stage you need to thoroughly clean the surface again.

Those parts of the surface on which spraying will not be carried out should be protected from foam with a piece of dense matter.

Safety precautions

Although PUF is not a toxic material, working with it can lead to accidents. In order to prevent this from happening, basic safety measures should be followed.

The most important safety features of the insulation process are serviceable equipment and protective clothing. The entire spraying process is best carried out in a special suit in which the human skin will be completely protected from contact with PUF. The mucous membranes of the eye should be covered with glasses, the respiratory tract with a respirator or gas mask.

The instruction will help beginners to properly prepare the sprayed composition and to load this heater with a construction gun. It is also required to have a special solvent on hand in order to rinse it off immediately if drops of foam insulation get on the skin. The cost of work is determined individually and depends on the complexity of the working surface and the thickness of the applied foam. The exact price of installing insulation can only be said after a visual inspection of the building.