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Do-it-yourself insulation with polyurethane foam: the process of insulating a house with polyurethane foam. High-quality roof insulation with polyurethane foam - the secrets and nuances of competent roof insulation Insulation with liquid polyurethane foam

A conscientious owner of his own house always considers the issues of warming his home to be paramount. And this is absolutely the right position. Well-planned and well-made thermal insulation performs several important functions at once. It significantly reduces the heat loss of the building, which makes it possible to create an efficient heating system in a residential building with minimal energy costs. Thermal insulation helps well on hot summer days - it will not be hot in the house, and air conditioning units will not work with excessive load. And, finally, it is a guarantee of their long-term operation, a decrease in the level of destructive external influences on the building materials of walls, ceilings, and foundations.

However, it must be remembered that improperly performed thermal insulation is quite capable of causing serious damage to the building. The choice of insulation materials is an extremely important issue, since not all of them are acceptable in certain cases. Polyurethane foam is considered one of the most promising modern thermal insulators. However. And heated debates do not subside around this material - someone considers it a material with practically no flaws, but there are those who subject it to ruthless criticism. Let's try to understand this issue - polyurethane foam insulation pros and cons, somewhat summarizing and systematizing information from numerous construction sites and forums.

What is polyurethane foam

In the practice of private housing construction, polyurethane foam in our area has become widely used not so long ago. However, for sure, everyone has been familiar with this material since early childhood: foam rubber - and this is also one of the varieties of polyurethane foam, was used to make sponges for taking hygiene procedures, it was also used as stuffing for soft toys or children's furniture.

The familiar foam rubber is also one of the varieties of polyurethane foam.

Of course, other types of polyurethane are used to insulate building structures, but the basic chemical composition and the principle of obtaining the material remain the same. A characteristic feature of all polyurethane foams is high gas content, reaching 90% of the total volume of the solidified mass.

So, polyurethane foam refers to porous gas-filled polymers based on polyurethane components. Depending on the specific components used, an elastic elastic structure (the same foam rubber) or a rigid one, which is mainly used in thermal insulation measures, can be obtained at the input.

When insulating certain building structures, ready-made thermally insulating polyurethane foam parts can be used, for example, panels, blocks, half-cylinders (pipe shells), etc. However, compositions that are applied to insulated surfaces (or poured into cavities) in liquid form, but have the ability to self-foam and quickly polymerize and solidify, have the highest demand. Thus, in fact, the preparation of the desired composition takes place directly at the site of the insulation work.

For large-scale work, two-component compositions are used. As a rule, modern technology involves the use of a polyol as a component "A", and a polyisocyanate as a "B".

Barrels with components "A" and "B"

The mixing of these components with the participation of a small amount of water leads to a polymer synthesis reaction with active release of gas (in this case, carbon dioxide), which creates a foamed, porous rigid structure. Such polyurethane foams have a closed cellular structure - the vast majority of air bubbles are completely isolated from neighboring ones.

The thermal conductivity of carbon dioxide filling the cells, under all other equal conditions, is significantly lower, by about a third, than that of air (0.016 W / m × ° C versus 0.026 W / m × ° C), which is another significant plus for polyurethane foam with closed cells, precisely as an effective insulation.

In some professional high-quality systems, freons are used as a blowing agent.

At the household level, as well as for carrying out operations limited in area and volume (filling gaps, small openings, carrying out repairs, etc.), one-component polyurethane foam compositions are more often used, better known to everyone under the name of mounting foams.

In fact, the components are already pre-mixed, and the composition required for polymerization is in pressurized cylinders. But for the final reaction, foaming and curing, contact with atmospheric oxygen and water is required (surface moistening and water vapor contained in the air). The result is a porous foam structure, the cells of which are open.

The structure of the hardened polyurethane foam is not so dense and homogeneous

The gas involved in forced foaming - freon, gradually disappears and is replaced by ordinary air, and such polyurethane foam cannot compete with closed-cell polyurethane foam in terms of thermal conductivity. He also loses in strength, resistance to external influences. Therefore, it is not worth seriously considering such compositions as the main ones for them - they have their own, and very popular, scope. The only criterion by which such an open-cell structure wins is sound absorption and sound insulation.

For comparison, the table below shows the main physical and operational parameters of both types of polyurethane foams:

Basic parameters of materials	Comparative characteristics
	Closed cell polyurethane foam (two-component sprayed)	Polyurethane foam with open structure (mounting foam)
Thermal conductivity coefficient, W/m ×°С	0.019 ÷ 0.035	0.025 ÷ 0.045
Number of closed cells	Over 90%	Less than 50%
Expansion (foam rise) from original volume	1: 40	1: 70 ÷ 90
Density, kg/m³	20 ÷ 200	8 ÷ 18
Vapor permeability	0.02 ÷ 0.05	0.07 ÷ 0.15
moisture absorption	1 ÷ 3%	10 ÷ 60%
Waterproofing properties	Yes	No
Sound absorption properties	good	high

How polyurethane foam is applied to insulated structures

Since the topic of the article is directly related to thermal insulation measures, in the future we will consider mainly two-component polyurethane foam, which has a closed cellular structure, leaving aside mounting foams.

Prices for sprayed insulation

sprayed insulation

The creation of insulated structures or the imparting of thermal insulation qualities to building elements can be carried out using two different technologies - spraying or filling cavities (pouring).

For sputtering, special technological installations are used. The layout of the complexes may be different, but in any case, the process boils down to the fact that the components "A" and "B" are taken from regular tanks or built-in tanks, pre-filled before starting work. Further, under the action of the pressure created by the compressor, the components, in transit through the control station, enter the spray gun.

The mixing of the components occurs already at the final stage - in the mixing chamber of the gun, and then under high pressure through the nozzle, the liquid mixture enters the insulated surface. In fact, the main polymer synthesis reaction, with the release of heat and a large amount of carbon dioxide, leading to abundant foaming, occurs already on the treated surface.

Both the very composition of the resulting polyurethane foam and its application under high pressure contribute to the excellent adhesion of the insulation to almost any surface - this is a distinctive feature and one of the key advantages of this material.

Video: wall insulation with polyurethane foam spraying

The control elements of the process plant allow precise adjustment of the percentage ratio of components in the mixture, which largely determines the performance of the resulting coating. The pressure at the outlet, the maximum flow rate of the material at the nozzle of the gun can be adjusted.

Despite the seeming simplicity of the technology, it has a lot of subtleties that only experienced specialists know. To carry out spraying on your own, even if you manage to rent a set of equipment, is a difficult task, unless, of course, the priority is the quality of the resulting insulation and the rational use of materials. By the way, many modern so-called "masters" offering their services in this area also often sin with low professionalism. Buying your own device for spraying polyurethane foam does not mean immediately becoming a qualified specialist, in direct analogy with the fact that buying a car cannot immediately make a new owner an experienced driver. By the way, in Europe, the operator of the PPU spraying plant belongs to the category of highly qualified workers, training in this specialty takes even more than one year, and in the course of work at least once every 6 months, it is considered mandatory to pass a control certification. So, when choosing a contractor for the insulation of your own home, considerable caution is required - it is better to give your preference to a trusted company that guarantees quality, even if the services are a little more expensive than those of an unknown private trader.

The leader in the production of PPU spraying equipment is the American company GRACO, which produces a whole line of special REACTOR installations of various capacities. And in the field of production of high-quality component compositions for obtaining polyurethane foams, the products of the BASF concern deserve the maximum marks. This can also be taken into account when choosing a contractor, having familiarized himself with his technical equipment.

The second option for insulating building structures with polyurethane foam is to pour the mixture into cavities specially left for this. A striking example is those built using "sandwich" technology.

Such work also requires knowledge of certain nuances and high experience of a specialist. The components are also supplied under pressure, but it is significantly lower than when sprayed onto the wall. Mixing is carried out in a special chamber of the gun, from where the mixture is already fed to the outlet, to the supply pipe. The equipment can be used the same as for spraying, only with a certain reconfiguration of the parameters. However, for the high-quality performance of work, there are also special filling installations, which provide for the use of special components with options for a kind of “delayed start” of foaming, so that there is enough time to introduce the mixture into the cavity (mould) before the active change in the structure of the composition begins.

In the structure filled with foam, holes are left in advance or holes are made for inserting the supply tube into the cavity, as well as for visual control of the filling level. The qualification of the master is of great importance here - you need to be well versed in the characteristics of the mixture being prepared: its expected volumetric expansion, the time for the full set of volume and the beginning of hardening. The operator must delicately maintain a balance between incomplete or loose filling of the cavity and possible ruptures or deformation of the insulated structure. A full-fledged visual control in such situations, as a rule, is impossible, and then the mistakes made can only be detected during the operation of the building or with the help of special equipment - a thermal imager.

For insulation of external enclosing structures, only polyurethane foam with a closed cellular structure is used. To create soundproof barriers in internal walls or ceilings, it is permissible, from the point of view of economy, to use cheaper open-cell foam.

Video: a good example of filling the cavity of a building structure with polyurethane foam

Real and far-fetched advantages and disadvantages of polyurethane foam insulation

It's time to talk about the advantages and disadvantages of polyurethane foam used for thermal insulation of building structures. To begin with, we will give a table with the main characteristics of the closed-cell material declared by manufacturers, and then we will analyze the main parameters in more detail.

The main characteristics of polyurethane foam	Indicators
Compressive Strength (N/mm²)	0.18
Ultimate bending strength (N/mm²)	0.59
Water absorption (% volume)	Max. 1 ÷ 3
Thermal conductivity (W/m ×°K)	0.019÷0.035
Content of closed cells (%)	up to 96
blowing agent	CO₂
Flammability class	B2
Fire resistance class	G2
Application temperature, not less than	+10 °С
Application temperature	from -150 ° С to +220 ° С
Application area	Thermal and waterproofing of residential and industrial buildings, tanks, cars, boats, wagons
Effective service life	30 ÷ 50 years
Moisture, aggressive media	sustainable
Ecological cleanliness	After full polymerization - it is safe. Approved for use in residential buildings. Used in the manufacture of food refrigerators
Pour Time (seconds)	25 ÷ 75
Vapor permeability (mg/m×h×Pa)	0.05 ÷ 0.07
Cellularity	closed
Density (kg/m³)	40 ÷ 120

Low thermal conductivity?

Polyurethane foam is rightly referred to as one of the most reliable thermal insulators. True, sometimes they attribute to it completely “fabulous” properties, up to a record low thermal conductivity coefficient of 0.017 W / m × ° С.

About 0.017 is not even worth talking about - it's just unrealistic. But an indicator of 0.20 is found in publications quite often. Is it really?

It is possible to talk about such high rates of thermal resistance only if all the requirements of the technology are strictly observed and the highest quality materials and equipment are used. In a word, such a level is achievable, rather, theoretically. Similar results can only be achieved using a closed cell spray system in which Freon acts as a foaming agent. r141b, which in most European countries is already simply prohibited for production and use. The density of the created polyurethane foam coating should not exceed 30 kg / m³, which is extremely difficult to achieve under normal conditions.

The thermal conductivity coefficient of 0.022 W / m × ° C is already a more realistic indicator, but even for such a level of thermal insulation, it is necessary to strictly follow the spraying technology, with a coating density of no more than 36 kg / m³, and using the same freon r141b, the prohibition of which has already been mentioned above.

Thus, for example, in Europe, such low thermal conductivity values are not even taken into account - a high-quality thermal insulation coating with a coefficient of about 0.028 W / m × ° C is considered there. But in fact, you can navigate something like this:

If systems with a closed cell structure and a foaming agent based on a mixture of Solkane® 365/227 freons are used, with unconditional observance of all the requirements of the application technology, then it is realistic to reach an indicator close to 0.026 W/m×°C. Alas, in our conditions, such systems are practically not used because of the high cost.
If systems are used that use water as the blowing agent (the most typical case), then at best the coefficient will be 0.030 W/m×°C.
If low pressure equipment is used, then the polyurethane foam poured into the cavity will ideally have a coefficient of 0.032 W / m × ° C.
When spraying, for reasons of economy, polyurethane foam coating with an open cell structure, the lower limit is 0.037 W/m×°C. This, again, is in theory, since the porous structure of such a PPU absorbs moisture quite abundantly, and the thermal conductivity in reality can be even lower.

You can upset the reader a little more - often the combination of all circumstances (the use of not quite high-quality materials or spray equipment, violation of technological rules, etc.) leads to the fact that in reality the coefficient rises to 0.040 or even more W / m × ° WITH. This, in particular, applies to the advertised "soft" polyurethane foam with an open cell structure.

There is one more nuance. Over time, even in a closed cellular structure of polyurethane foam, freon or carbon dioxide diffuses with their weathering and gradual replacement with ordinary air. Therefore, thermal insulation qualities may decrease.

In general, even 0.030 and even 0.036 is quite a worthy indicator for a high-quality thermal insulation material. But it's still not worth counting on absolutely fantastic 0.020 or 0.022.

Excellent adhesion to all surfaces

This quality of polyurethane foam is considered to be one of its most important advantages. In many ways, we can agree with this, but still - with reservations. Not every polyurethane foam has such outstanding features, and it does not "glue" to all materials in the same way.

A simple example - normal adhesion with polyethylene will never be ensured. Serious problems are not ruled out if polyurethane foam is applied to a completely unprepared base, for example, with remaining whitewash or thin peeling plaster, which has not been cleaned of dust and dirt and degreased.

High-quality professional polyurethane foam systems are contraindicated in contact with a wet surface, while open-cell compositions, such as mounting foam, on the contrary, even require a certain amount of moisture.

It is also ridiculous to say that polyurethane foam has higher adhesion than any other compositions - there are primers, varnishes and paints that fit perfectly on galvanized metal, and in the case of polyurethane foam spraying, incidents can also happen here. For example, systems using water as a foaming agent should not be applied to galvanizing - good adhesion will not be achieved.

One more remark on this matter - it is possible to speak of high adhesion only if we are talking about PPU with a closed cell. There are cases when the applied layer of open-cell polyurethane foam simply flew around even under the influence of its not very large weight.

The only thing we can fully agree with in this aspect is that the adhesive qualities of polyurethane foam are such that the installation of the insulation layer will definitely not require additional materials and fasteners. This advantage is undeniable. And to evaluate the degree of adhesion is still the lot of technologists.

Is the process of applying polyurethane foam thermal insulation quick and easy?

Such a statement can be called controversial. To be more precise, it is better to divide it into two concepts - then it will be easier to “put everything in place”.

In terms of the speed of applying polyurethane foam by spraying, the process is indeed the leader. Of course, there is a certain dependence on the design features of the building, number of storeys, wall configuration, etc. But when compared with any other insulating material, then there are simply no competitors in terms of the rate of thermal insulation of the surface.

As for simplicity, the picture is somewhat different. It has already been said about the qualifications of the craftsmen and the quality of the equipment used and the materials used - there is no “smell” of simplicity here. Another thing is that the spraying technology makes it easy to apply polyurethane foam to the most complex shapes and to the most inaccessible places. At the same time, the process is practically waste-free (with a highly qualified operator), the coating is uniform and seamless, which greatly simplifies subsequent operations, and without "cold bridges" - the effectiveness of thermal insulation from this increases dramatically.

By the way, one of the generally recognized shortcomings of polyurethane foam insulation is precisely the difficulty of performing such work on our own.

Very high service life of polyurethane foam insulation?

Again, such a statement cannot be called categorical.

Firstly, it is possible to talk about a long service life only when using polyurethane foam with a closed cell structure. Those inexpensive open-cell coatings that are applied from the outside and become exposed to the most common atmospheric humidity (even without taking into account the likelihood of direct precipitation on them) are unlikely to last long. In terms of moisture absorption, they are no better than the same mineral wool, and it is at least naive to talk about decades of operation.

The worst enemy of polyurethane foam is the ultraviolet component of the solar spectrum

Secondly, even if high-quality closed-cell polyurethane foam is used, the ultraviolet component of the solar spectrum always contributes to a reduction in the service life. The material undergoes destructuring, becomes brittle, brittle, begins to succumb to abrasive abrasion and weathering. Even the highest quality PU foam systems can lose up to 1 mm of thickness per year due to exposure to sunlight. This is one of the negative qualities of polyurethane foam, and it must be taken into account when planning thermal insulation work.

Thirdly, not too high durability of the material can be caused by an incorrect percentage of components, a violation of the spraying technology (this is often the fault of many "offices" working in this field, using, for example, low-pressure equipment for applying the outer layer to the walls). And this is again an emphasis on the right choice of contractor.

But in general, if all the necessary conditions are met, then we can safely say that polyurethane foam is indeed the champion of all wall insulation. Evidence of this is the dismantled old houses in Northern Europe, which have served for 50 years or more - polyurethane foam thermal insulation layers remained intact and retained their basic qualities.

Biological stability - mold does not appear on PU foam, mice do not gnaw it?

Again, clarity needs to be clarified.

Let's start with mold and other microflora. Colonies are formed where favorable conditions are created for this. This is high humidity and a certain temperature regime. Thus, if, by coincidence, the necessary "microclimate" is created, then mold may well appear on the surface of the material (if we are talking about a closed cellular structure), or even in its thickness (with open cells). This, for example, can be a closed and poorly ventilated room.

At the same time, with high-quality insulation with closed-cell polyurethane foam, the likelihood of the appearance of conditions for the development of microorganisms is not so high. The insufficiency of thermal insulation qualities, ending in constant accumulation of condensate, is not necessary to wait when using even a not so thick layer of polyurethane foam, and the closed cell does not accumulate moisture from the air. But the low probability of the appearance of "nests" of mold or fungus is not at all associated with any special antiseptic qualities of the material - everything follows from its main thermal characteristics. Well, polyurethane foam itself is certainly not a nutrient medium for microflora.

The next question is. It can be divided into two aspects.

To say that polyurethane foam becomes an obstacle for them is completely unfounded. Yes, this polymer is absolutely not digested by their digestive system, but it is not a poison either. Just like that, of course, a mouse or a rat will not gnaw polyurethane foam - it does not represent any nutritional value for them. But if rodents need to make a passage from the street to a dwelling or to a food store, then the PPU layer will not be able to stop it.

Another thing is that in closed-cell polyurethane foam (as, indeed, in extruded polystyrene foam), mice or rats never organize their nest. In mineral wool or ordinary foam, the rodent settles willingly - the conditions necessary for life and reproduction are easily created there. And any cavity in PPU or EPS is a chamber impervious to air and moisture, in which normal heat exchange and long stay are impossible.

Conclusion - polyurethane foam will not become an obstacle for mice or rats, but it will not be a habitat either. We repeat - this applies to PPU with a closed cell. In an open-cell structure, nothing will prevent mice from making their warm and cozy “palace”.

Is polyurethane foam an absolutely environmentally friendly material?

This statement is very close to reality. If you "look around", you can not help but see that polyurethane foam is used in everyday practice almost everywhere, including in conditions of constant contact with the human body, with food, with medical equipment, etc. Is this not an indicator of environmental friendliness?

But here an extremely important caveat follows - this will all be fair if only high-quality components were used during spraying (pouring), professional equipment was used, and the work itself was carried out by a truly qualified craftsman. The fact is that the initial components are toxic and belong to II and III hazard groups, which, after mixing, reaction and polymerization, turn into completely safe polyurethane foam. However, the low quality of the initial compositions, incorrect proportions of feed to the mixer, other violations of the technology can shift the required balance, unreacted components remain, and the resulting coating can “acquire” very toxic properties in one direction or another. The negative reviews about polyurethane foam found on the network that it emits a pungent odor that causes discomfort - with 100% probability are caused by just such circumstances.

Another thing is that the deposition process itself requires extremely responsible security measures. Work should be carried out in special equipment, with mandatory protection of all exposed areas of the skin and mucous membranes. Particular attention is to ensure respiratory protection. According to the existing technological requirements, fully closed masks with a forced supply of clean breathing air should be used for this. By the way, this is another criterion for the conscientiousness and qualification of the craftsmen. If it is noticed that the workers are spraying in ordinary clothes, and of all the protective equipment they use only a gauze bandage, these are definitely “shabashniks”. If their leader does not take care of the health of his employees, he is unlikely to have a “headache” for the quality of the insulation being performed.

Very often, the most environmentally friendly materials are presented with natural heaters - such as moss, sawdust, linen tow, straw, etc. Everything seems to be correct here, except for one moment. Specifically, such materials become a rich breeding ground for microorganisms and insects, actively absorb a wide variety of substances from the surrounding air, which may well pose a danger to human health. High-quality closed-cell polyurethane foam has no such disadvantages.

You can immediately note the chemical resistance of polyurethane foam to the overwhelming amount of substances used in everyday life. He is not afraid of solutions of acids and alkalis (except for highly concentrated ones). Unlike, say, even extruded polystyrene foam, it can be decorated with any plaster compositions and paints on any basis.

Does the use of polyurethane foam allow you to abandon the vapor and waterproofing?

This advantage is valid only for closed-cell PPU. Indeed, both in the roofing and in the wall "pie" (with external spraying of the material on the walls), there is no need to use a hydro-vapor barrier internal and windproof waterproof membranes. And this, I must say, is a very significant simplification of the entire general process of work and a significant savings effect.

However, it should be borne in mind that this is not always good. On the Internet, for example, there are constantly heated debates about the vapor permeability of materials. According to the "classic" scheme, it should increase in the direction from the inside of the premises towards the street - this ensures free removal of water vapor and reduces the likelihood of condensation in the thickness of the wall structure. The use of polyurethane foam can violate this pattern. In order for the room to be insulated from the outside to remain within the normal temperature-humidity balance, special attention will have to be paid to ventilation issues, or to provide for interior decoration that would prevent the penetration of vapors through the walls from the inside.

Insulation of a wooden frame with polyurethane foam is a very dubious event

The spraying of polyurethane foam on a natural wooden log house is not particularly welcome, especially recently erected, the logs in which have not yet had time to free themselves from excess moisture. If you look at the vapor permeability table, then the indicator for sprayed polyurethane foam and softwood across the fibers is approximately the same, about 0.05 mg / m × h × Pa. Polyurethane "fur coat" under certain conditions can "preserve" moisture in the wood, and this is dangerous by the occurrence of putrefactive processes. But for wood composites (plywood, OSB, chipboard), polyurethane foam is safe - its vapor permeability is even higher than theirs.

But polyurethane foam with an open cellular structure - practically does not differ from others in this respect. When using it, the use of hydro and wind protection will become a prerequisite.

Is the material fire retardant?

It must be said right away that technologists have not yet succeeded in creating a completely non-combustible polyurethane foam. With polymers, this is generally an extremely complex issue simply because of their molecular structure and component composition. Another thing is how combustible it is and to what extent it is dangerous in the event of a fire.

If the owner of the house chooses an inexpensive material from some eastern manufacturer, then this is most likely G-4 class polyurethane foam. And it should be noted that everything that burns belongs to this class. In such formulations, flame retardant additives are not used at all, or their concentration is frighteningly low. One can say unequivocally about such material - it burns “quite decently”, and it becomes a very difficult task to put it out. And he not only burns, but also becomes a flame spreader. Unfortunately, modern history is full of cases when, for example, polyurethane foam spraying caught fire from welding and burned out completely, which led to deformation and destruction of even strong wall structures. Thus, acquiring incomprehensible material from an unknown manufacturer, the owner to some extent "lays a mine" under his own home.

Since the “NG” class is still an unattainable horizon, technologists are trying to minimize the flammability of polyurethane foam by introducing special additives. Most of the high-quality compositions can already be classified as G-3 - the material will not ignite on its own, without exposure to an open flame. When the source of fire disappears, polyurethane foam dies out, coke, preventing the flame from spreading further. Unlike - it does not melt and does not flow. Smoldering of coked material is possible, but even under these conditions, combustion products are not as toxic as when burning foam, although they also pose a very formidable danger to human health and life.

There are also more fire-resistant varieties of polyurethane foam, which are classified as G-2 and even G-1. However, they have not yet received wide distribution. Their insulating qualities are lower, and the cost is about 3-4 times higher than that of popular G-3 class systems.

By and large, the degree of fire safety of the entire building only slightly depends on the type of insulation - usually this indicator is based on the correct structure of wall and roof structures. And high-quality polyurethane foam, even class G-3, can rather play a positive role here.

The consequences of a fire - polyurethane foam did not allow the fire to spread

For example, the photograph below shows the aftermath of a fire that occurred in a room above. The sprayed polyurethane foam on the ceiling burned out and coked, but did not transfer the flame below. At the border of the ceiling with the wall and on the upper part of the wall, the material was only touched by thermal decomposition, and below it, it generally remained intact. In addition to, in fact, low combustibility, this was also facilitated by the extremely low thermal conductivity of the material - it does not contribute to the spread of high temperatures necessary for the emergence of a flame.

So, in the publication quite objectively, from the point of view of the author, the main properties of polyurethane foam used as a heater were considered. Having become acquainted with the advantages and disadvantages of this material, having studied the possibility of inviting really qualified specialists with high-quality component systems and cool equipment, having roughly calculated the “bookkeeping” of the upcoming work, it will be possible to make a decision. If the arguments seem unconvincing, you have every right to choose any of the other heaters suitable for this design.

Variety of insulation materials

The comparative analysis given in a special article of our portal will help you choose the right one.

Calculator for calculating the thickness of the insulation layer

And one more help to the reader - to quickly evaluate and compare the effectiveness of heaters and accurately calculate the required thickness of the thermal insulation layer on the wall, a special calculator below will help.

To use it, you must first find the value of the required heat transfer resistance, calculated for a particular region. It is shown on the map below. Purple numbers are taken into account - for walls and enclosing structures.

After that, it remains to enter the requested values and indicate the planned or existing parameters of the wall structure (if the exterior finish is made according to the principle of a ventilated facade, it is not taken into account). The program will perform all other calculations itself.

Polyurethane foam (PPU) is a liquid heat insulator that is applied directly to the surface using special equipment. Thanks to the spraying technology, an integral uniform layer is created, the energy efficiency of which is much higher than when using classic heaters (mineral, basalt wool, polystyrene, glass wool, extruded polystyrene foam). Reviews of PPU insulation confirm the effectiveness, for example, a 2-centimeter layer of polyurethane foam is comparable in efficiency to a 20-centimeter mineral wool.

What are the opinions?

“According to reviews, thermal insulation by means of PPU spraying is an economical and durable method. From personal experience, I can say that it allows you to reduce the cost of heating industrial buildings by 30%. For my hangar, I used the method of internal application, since it is resistant to biological decomposition, inert to chemical environments and high strength, which makes it indispensable for thermal insulation of such buildings.”

Alexander Boyko, Moscow.

“Reviews about polyurethane foam are rather ambiguous: the material is strong and durable, but expensive to install. I want to say that it is better to spend money on insulation once than to constantly lose money on paying for energy resources. I have my own service station, with a similar building, it should be remembered that not every insulation is able to maintain its characteristics when in contact with gasoline vapors and engine oil. I opted for PPU, because it is resistant to chemically aggressive environments.”

Vasily Arkadyevich, Samara.

“Polyurethane foam is a universal insulation that is suitable for various structural elements of a building. I used a liquid thermal insulator to insulate a wooden house with an attic, since it does not exert additional load on the structure and allows you to create a uniform layer for structures that have a complex configuration (attic walls and ceiling).

Igor Vlasov, Ufa.

“Reviews and opinions about PPU indicate high protective properties. I decided to buy a material for insulating a metal garage, since the thermal insulator is applied thinly, which saves usable floor space and protects the metal from corrosion.”

Sergey, Leningrad region.

“I want to say, as a person who has been working with a liquid heat insulator for a long time, that it is impossible to spray polyurethane foam with your own hands, since you need special spraying equipment. It is best to entrust this to professionals: a team of 2-3 people is quite capable of insulating a hangar with an area of 1,000 m 2 in 2-3 days.

Kirill Korshun, Smolensk.

An overview of PPU insulation indicates the possibility of using it for buildings built from various materials. Polyurethane foam has high adhesion, which provides reliable adhesion to the insulated surface, therefore, there is no need for additional fasteners. In addition, the insulation has sufficient vapor permeability and hydrophobicity, which makes it impractical to install hydro and vapor barriers.

Advantages and disadvantages of polyurethane foam

The advantages of the material include:

high vapor permeability;
low coefficient of thermal conductivity;
fire safety;
environmental friendliness;
durability;
biological and chemical inertness;
hydrophobicity;
adhesion, which makes it possible to mount it directly on the surface without a frame device and the use of fasteners;
light weight;
small thickness of the layer with its energy efficiency;
application for external and internal insulation;
uniformity and integrity avoids the occurrence of cold bridges.

PPU is easily applied to various surfaces, suitable for structures with a complex configuration.

The main disadvantages are the high price and the impossibility of performing thermal insulation work by spraying polyurethane foam without special equipment. As for the cost, it varies depending on the material of the insulated plane, as well as the configuration of the building.

Polyurethane foam can rightly be called a new generation of insulation. In recent years, this technology of thermal insulation of buildings is gaining more and more popularity among the owners of private houses. Do-it-yourself insulation with polyurethane foam is quite possible, but only if the necessary equipment is available, the master has studied the technology of applying this material quite well.

Polyurethane foam is suitable for insulating buildings both from the outside of the walls and from the inside. The material has a large number of positive qualities, and therefore has been used more and more recently. However, you need to be aware of the negative aspects that may arise when using this type of thermal insulation.

How polyurethane foam is used for insulation

Insulation with polyurethane foam is most often done by spraying a heat-insulating layer on almost any surface. Adhering well to it and gaining volume, the foam composition increases in size several times. Polyurethane foam, expanding, penetrates into all, even the smallest cracks, creates a dense and practically airtight coating, thanks to which the walls and roof are not afraid of cold and wind.

The most common method of using polyurethane foam is spraying it on walls.

Most common the method of its installation is spraying, but it should be noted that the pouring method is sometimes used. Most often, this technology is used at the stage of production of thermal insulation structures. Polyurethane foam is poured into special molds, and the resulting parts are used only after complete solidification.

Another pouring option is to fill with foamed composition certain horizontal areas or voids where spraying is not possible. For example, this method is used when it is necessary to fill a cavity between already installed or erected walls, or the space between installed layers of finishing material.

Polyurethane foam is a mixture of two of its constituent polymers, which are usually in liquid form - a polyol and a polyisocyanate. These components are mixed together without air access during the spraying process, foaming when exposed to carbon dioxide and heated to a high temperature.

The finished mixture is fed through hoses to the spray gun and applied to the structure, thanks to the high pressure generated. The foam composition perfectly adheres to the prepared surface and begins to actively expand, forming an insulating layer of the desired thickness.

Video - Modern method of thermal insulationII - polyurethane foam spraying

Polyurethane foam properties

This material is used for insulation of both industrial and residential premises. Polyurethane foam spraying is carried out on the floors of houses, the inner surface of the roof, various partitions, floors and walls. It is especially popular for warming the walls of frame structures.

Polyurethane foam is universal - it can be used to insulate walls, floors, ceilings, roofs, etc.

During the period of its active use, it has shown its unconditional effectiveness not only as a heater, but also as a waterproofing and soundproofing material. It perfectly protects the premises of the house from freezing, moisture penetration and external noise.

The main advantages of polyurethane foam

So, the remarkable properties of polyurethane foam include:

Excellent adhesion, that is, reliable adhesion to almost any surface, be it concrete, wood, metal or roofing from other materials.
The low thermal conductivity of polyurethane foam allows you to save the accumulated heat in the premises, if the insulation is made from the inside, it creates a reliable barrier against the penetration of cold air, if the material is sprayed from the outside of the walls.
Polyurethane foam tightly fills all holes and crevices, which helps to isolate the room from extraneous street sounds. When sprayed on the inner surface of the roof, the insulation is able to drown out the sounds of raindrops, which is especially important for rooms located in the attic of houses.

This insulation counteracts the appearance of corrosion on metal structural elements and protects the surface from the negative effects of an external aggressive environment.
When spraying polyurethane foam, it covers not only large surfaces, but also neutralizes cold bridges that occur at the locations of the batten guides. No other types of material can close them as reliably, therefore, even if insulation is used in mats or slabs (for example, mineral wool or polystyrene foam), cold bridges are still treated with polyurethane mounting foam.
Spraying can be carried out on the most complex structures in their configuration, on which it is simply impossible to install conventional heaters.
Polyurethane foam refers to slow-burning materials, since polyol substance A is included in one of its components. One of the flame retardants giving the insulation the ability to self-extinguishing, to cessation burning even if the material enters the fire zone. The ignition of polyurethane foam is possible only at temperatures not lower than 450-500 degrees.
The light weight of polyurethane foam allows it to be sprayed on any roofing material from the side of the attic or on the attic floor, without fear of weighing down these building structures. Moreover, the applied layer of insulation after complete solidification will also give them additional rigidity.

Video - The use of polyurethane foam for roof insulation

When sprayed, the material forms a seamless surface, which cannot be done using other heaters without using additional means for their connection (mechanical or adhesive).
Polyurethane foam is applied very quickly, expands and hardens in a short time. Therefore, the whole process of insulation will take a little - only one ÷ two days, depending on the area and complexity of the structures to be insulated.
Due to the moisture resistance of polyurethane foam and the ability to seal surfaces, when using it, there is no need to use a vapor barrier and windproof film.
Polyurethane foam is not subject to decay, mold, damage and insects.
Leading manufacturers establish a guarantee for the life of polyurethane foam in 50 years. However, judging by its components and application technology, the insulation will last much longer without losing its qualities if the PPU spraying and its exterior finish are arranged correctly.
Such high scores does not possess not alone existing insulation material, as not alone of them does not possess such adhesive properties.

Material disadvantages

It is impossible not to say about the shortcomings of polyurethane foam - with self-insulation by it and during further operation:

The big disadvantage of this insulation technology is its price, since buying or even renting equipment for applying polyurethane foam is not cheap.
For work on spraying, it is necessary to purchase personal protective equipment - a special suit and a respirator to protect against damage to the respiratory tract. Be sure to cover all areas of the skin, mucous membranes, eyes.

In the absence of experience in the installation of such a heater, the work may drag on for a long time, and its quality will not be guaranteed.
Polyurethane foam is not combustible, but when in contact with fire, it smokes heavily. At the same time, the smoke contains a large amount of substances harmful to humans.

Polyurethane foam should never be left open for a long time to sunlight - ultraviolet quickly "kills" the material

If the insulation is applied from the outside of the building and is not covered with finishing materials, then it quickly begins to break down under the influence of ultraviolet radiation, decomposing at the same time into monomers that are dangerous to human health.

How to make insulation with polyurethane foam

Many would like to carry out the process of insulating their own housing with polyurethane foam on their own, however, you need to know that this is quite possible only theoretically, but in practice you will need specific equipment, materials and certain work skills. It should also be noted that the technological equipment requires a certain adjustment before the start of deposition, and it is necessary to be able to do it correctly.

One of the main difficulties is the need for special equipment for spraying polyurethane foam.

If there is an idea of how the whole system works, but there is no equipment, it can be rented, for which, however, as mentioned above, you will also have to pay a lot.

So what can be the conclusion? Probably, it will be easier to invite a master with his own equipment - he will quickly, without delay, complete all the technological steps for warming, freeing the homeowner from a lot of problems.

If, nevertheless, it is decided to test your own strength, then you need to take into account some features of such a process:

Warming with this material can be carried out during the construction of a building or in an already built house. In addition, spraying is carried out on separate areas or on the entire surface. Or, if necessary, fill the cavities with polyurethane foam.

We insulated the house from the outside, and now find out and also consider options on how to choose the right insulation from our new article.

When carrying out work, it is necessary to take into account the region where the building is located, since the thickness of the sprayed layer of insulation will depend on climatic conditions.

The measures for insulation with polyurethane foam include the following actions:

Insulated surfaces require some preparation. For example, existing old coatings should be removed from walls if they are clearly unstable (such as old crumbling plaster or peeling paint).
Further, on the wall it is necessary to arrange a crate of wooden bars or metal profiles. The thickness of the guides is selected depending on which layer of insulation should be applied to the surface.

In addition, the crate can play a leveling role for the wall. It is mounted on the wall surface in terms of level and plumb, and the openings between its elements are then filled with polyurethane foam, which will fill in the bumps and bring the coating to the proper level.
A foaming insulation is sprayed onto the prepared plane using a special gun.
The intensity of spraying also needs to be adjusted, since if a layer that is not too thick is needed, then it is necessary to set up the apparatus in such a way that the composition is sprayed in very small jets. Lathing, in this case, must be made of bars or profiles having a small thickness, as they will determine the thickness of the insulation layer.
Spraying polyurethane foam always start from the bottom of the wall, and apply it to the surface between the elements of the crate.

Polyurethane foam is applied in a thin layer, which immediately acquires volume. If the thickness of the first layer is not enough, then another layer of insulation is applied on top.

After the polyurethane foam has hardened and the frozen coating has been leveled along the batten guides by cutting off the protruding reliefs of the insulation, it is fashionable to install siding and lining. Nothing prevents you from doing outside and brickwork or plastering the walls of the house.
If it is planned to plaster the wall after insulation, then it must be tightened with a chain-link mesh, fixing it on the rails of the crate. Then apply the cement mortar to the wall using the throwing technique. After its setting and initial hardening, it will be possible to apply any leveling composition of the plaster, as it will lie well on this base.

Video: the process of self-applying polyurethane foam on the wall

In conclusion, I would like to note that two factors are very important in any work on insulation - the quality of the material used and the experience of the master. Therefore, it is best to entrust the work to a proven specialist who will save you from unnecessary worries and carry out spraying quickly and efficiently.

Prices for popular models of air compressors

Air compressors

Step-by-step instructions for insulation with polyurethane foam using a disposable kit "PENOGLAS ™ KIT"

The appearance in the assortment of stores of disposable kits for applying polyurethane foam has significantly expanded the horizons for using this effective insulation. It is possible to do without inviting a team of specialists with their equipment. The kit provides everything you need, up to personal protective equipment, without which it is not recommended to work with polyurethane foam.

One of the brightest examples of such equipment is a set of domestic production - "PENOGLAS ™ KIT".

The whole set is placed in three boxes, with a total weight of about 30 kilograms. Everything is very compact, so a normal car trunk is enough to carry the whole set.

The manufacturer declares the following physical and operational characteristics of the created thermal insulation:

The system is two-component, giving foam with a closed cell structure, which minimizes possible water absorption.
The density of polyurethane foam after complete curing is from 35 to 40 kg/m³.
Thermal conductivity coefficient - 0.024 W / m × ºС.
The number of closed cells is not less than 85%.
The full volume expansion of the PENOGLAS™ KIT-400 kit is 1 m³, which will correspond to an area of 20 m² covered with a 50 mm thick thermal insulation layer.
The period of complete solidification of polyurethane foam is 1 hour.

The kit includes:

Two cardboard boxes, each of which contains a cylinder with one of the components. Both the boxes and the cylinders themselves have a clear color and letter marking: component “A” is indicated in red, component “B” in blue. The components are in cylinders under pressure of 8 atmospheres.

When working with the kit, the cylinders are not removed from the boxes - the very design of the package allows you to carry out all operations without completely removing it.

The third box contains all the fixtures, tools and spare parts necessary for the job. It contains:

- Spray gun, in which the components are mixed. Two flexible transparent hoses are connected to the gun, ending with fittings with union nuts - for connecting to cylinders. Typically, the hoses are also color-coded - so that when reusing the kit, you do not get confused with the “polarity” of connecting to the cylinders. The length of each hose is 3 meters.

- For spraying a mixed composition, special interchangeable heads with a spray nozzle are put on the gun. The set includes ten such heads.

Silicone grease is used to facilitate the attachment of heads to the gun and ensure a reliable seal of this connection - a small package of it is included in the kit.

Attaching the hoses to the cylinders requires tightening the union nuts with a wrench, which is also provided in the accessory kit.

- The manufacturer also thought about the observance of safety measures - the basic kit always includes a set of personal protective equipment - gloves, goggles and a respirator.

Working with the system "PENOGLAS™ KIT-400" is quite simple and does not require any special qualification of the user. The entire assembly and preparation of equipment for use takes a matter of minutes. There is no need to use any power sources - the kit is completely autonomous. More details about this are in the instruction table below:

Illustration	Brief description of the operation to be performed
	The kit is delivered to the place of work. A small box is opened - you need to get it and immediately put on protective equipment.
	Gloves can be rubber or polyethylene. You can, of course, use your own, but the use of protective equipment is a prerequisite, since the components of PPU are very toxic, and the resulting foam is very difficult to wash off from the skin. It is not included in the kit, but it is also strongly recommended to use a disposable work suit - it is impossible to wash off the foam that has got on ordinary fabrics.
	Boxes with cylinders are being prepared for work. You can open the top covers of the boxes completely by cutting a strip of adhesive tape with a knife ...
	..and then - unfastening the locking connection of the cover.
	And you can even just push inside the windows on the lid, perforated around the perimeter. By the way, these windows are also convenient for carrying boxes - immediately below them are the metal handles of the cylinders.
	On the side wall of the box there is another window - a round shape. It is also easy to push it inward - there is a cardboard perforation around the perimeter. Directly behind this window is the fitting of the cylinder with the PPU component.
	The illustration clearly shows the threaded fitting of the cylinder and the valve - to open the supply of the PPU component.
	A spray gun with hoses attached to it is taken out of the box.
	Hoses collected in a bay must be unwound along the entire length.
	The ends of the hoses with connecting fittings (with union nuts) are near the windows of both boxes. Please note that hoses may be color-coded and should be adhered to. Of course, by and large, there is not much difference which hose to which cylinder to connect now - no. But it happens that the work needs to be suspended, rescheduled (it is allowed to use the contents of the cylinders for one month) or move to another facility. The system can then be temporarily disassembled. It is also practiced that during large-scale work, several pairs of cylinders and one set of accessories for them are purchased. Here it will be extremely important to keep the same “polarity” that was during the initial assembly. And color coding will help in this. By the way, there are kits that do not have color markings on the hoses - you should pay attention to this.
	The ends of the hoses are brought into cardboard boxes through round windows.
	Then the union nuts of the hoses are screwed onto the fittings of the cylinders with PPU components. At first, as far as possible, twisting is carried out manually ...
	... and then the connection is tightened with the wrench included in the delivery. In exactly the same way, the operation is repeated on the second balloon.
	Next, you need to make sure that the pistol trigger is locked. The spray nozzle should not be on it yet. After that, both valves on the cylinders are fully opened. It is necessary to take an empty plastic bag (or any other unnecessary container), and make a trial release of the components into it, for two to three seconds. This ensures that the pressure of the components is even in both hoses and that nothing prevents them from passing freely through the gun.
	Next, you need to put a spray nozzle on the gun. To facilitate this operation, use the special silicone grease included in the kit. They coat the end of the gun with it ...
	... and the cylindrical part of the removable nozzle and the nozzle at the edges.
	Then the spray nozzle is inserted into the gun and pressed firmly, so that the connection is securely fixed by the stopper located at the top of the gun (well shown in the illustration - yellow).
	Cylinders are located in a convenient place for work, taking into account that the length of the hoses is three meters. It is allowed to move the cylinders only by the metal handles located on their bodies. Carrying by the crane is strictly prohibited!
	You can proceed to the application of polyurethane foam. The gun is directed to the area to be insulated. The optimal distance from the spray nozzle to the surface of the building structure is 600 mm. Spraying is carried out sequentially, in a thin layer, gradually moving the polyurethane jet to the untreated areas.
	Often they start from traditionally hard-to-reach or vulnerable places in terms of the formation of “cold bridges”. This illustration shows that the wizard first processed the corners between the floor beams and the rough coating, and then proceeded to fill in the free space between them.
	And this illustration shows the foam filling of the often overlooked area of \u200b\u200bthe connection of the Mauerlat, floor beams and rafter legs. The use of polyurethane foam allows you to cope with this task.
	This technology is also excellent for filling other voids formed at the junctions of building structures. For example, the figure shows the insulation of the junction of an old partition with a newly erected ceiling - filling this gap with polyurethane foam will provide both insulation and the necessary sound insulation.
	Polyurethane foam also fits perfectly on metal structures, which, due to their very high thermal conductivity, are always the most pronounced “cold bridges”.
	Do not try to immediately apply a thick layer of thermal insulation. The foam expands very quickly and without experience with this material it is very easy to make the mistake of wasting material unnecessarily. The optimal solution is to apply a thin layer, and after about 20 minutes, evaluate the degree of expansion of the foam. If necessary, then briefly bring the insulation layer to the thickness required by the calculations. (The calculation of the thickness of the insulation will be discussed below).
	In the process of work, it is necessary to monitor the quality of the applied foam. So, if it does not rise well or has changed in color (it has become darker or a pronounced brown tint has appeared), then the mixing proportions are violated. If the canisters are not empty and the hoses are fine, there is a good chance that one of the channels in the mix/spray head is clogged. There are spare heads in the kit, and, therefore, it is necessary to replace. To do this, the trigger lever is placed on the lock. Then the interchangeable head stopper is lifted.
	The head is gently pushed forward with the force of the fingers.
	Its cylindrical guides come out of the channels of the gun, and then it is completely removed and removed as unnecessary.
	To install a new head, the above-mentioned lubrication of the mating areas with silicone grease is carried out. Then the head is inserted into place ...
	... and sags with the force of the fingers to the end, so that the upper stopper, which fixes the atomizer in the gun, works.
	After that, you can again proceed to the spraying of polyurethane foam - the normal mixing of the components and good spraying of the jet will be restored.

When working, it is necessary to monitor the constant observance of safety precautions. If the components or the finished foam get on unprotected areas of the body or, even worse, on the mucous membranes, it is necessary to immediately rinse out with plenty of clean water. When washing off the skin, you can use ordinary soap. Foam that has frozen on your hands will not give in to soap - you can wipe it off with a rag soaked in a nitro-based organic solvent (acetone or 646).

What should be the thickness of the insulation sprayed with polyurethane foam?

In order to determine this parameter, you can independently carry out a thermal calculation. Its meaning lies in the fact that any building structure (wall, ceiling or roofing) after insulation must have a total resistance to heat transfer not lower than the normalized value established for a given area, taking into account its climatic features.

The initial data will be:

Parameters of the insulated structure. This refers to its thickness and the coefficient of thermal conductivity of the material of manufacture. In addition, the structure may have a multilayer structure. For example, a wall (ceiling, inner side of a roof slope) has a continuous finish (sheathing) made of a material that also contributes to the overall thermal insulation. Those layers that are separated from the outside of the building from the main structure by a ventilated gap (ventilated facade or roof) are not taken into account.
Normalized value of resistance to heat transfer. It can be determined by the proposed map-scheme - for your region.

Map-scheme for determining the normalized value of thermal resistance for building structures

Please note that for each area, three values \u200b\u200bare indicated - separately for walls (purple numbers), floors (blue) and coverings (red). They differ significantly, and it is necessary not to confuse the values when calculating the thickness of the insulation of a particular structure.

Knowing the listed values, it is possible to carry out the calculation using a special formula. The formula, however, will not be given, because below is a convenient calculator for quick and accurate calculations. All the necessary dependencies and table values are already included in it.

Before purchasing any material, each consumer considers the shortcomings. Polyurethane foam is no exception. About this material, which is otherwise called PPU, every builder has heard a lot of information today.

What material to choose

If you have ever thought about warming your home, then you probably paid attention to this option as thermal insulation. Maybe he will be the best solution, because along with the shortcomings, he has many advantages.

Description

Polyurethane foam, the shortcomings of which you should be aware of before starting work on insulation, is a type of plastic. Products from it have a cellular structure. The composition of polyurethane foam includes a gaseous substance, which is contained in a volume of 85 to 90%. The whole structure consists of small cells, which are well isolated from each other by walls, it is these cells that are filled with gas. The remaining percentages of the volume are the solid part, namely the walls themselves.

The disadvantages of polyurethane foam as a heater should be considered. Varieties of polyurethane foam are used quite often today, the material is popular among consumers, since it is very simple to make it, you can do it directly at the construction site. In this case, the two liquid components must be mixed, after which they will enter into a chemical reaction. If the necessary proportions of the ingredients are observed, then a polymer will be synthesized, which is represented by a hardened foam. If you slightly change the technology of preparation, then you can get polyurethane foams, which differ in characteristics from each other. Some of them are suitable for insulating doors and windows, while others are suitable for thermal insulation of buildings made of reinforced concrete or brick. As for the third varieties, they are widely used for pipelines. Thus, depending on the proportions of substances, polyurethanes can be obtained at the output, which consist of many cells of different sizes. Their walls can have different thicknesses, as well as strength.

The main disadvantage of polyurethane foam

Polyurethane foam, the disadvantages of which will be presented below, can be used in many areas of construction. However, before purchasing, it is important to take a closer look at the cons of the material. The main one is the negative effect of sunlight on the surface, which can cause rapid wear of products. In order to exclude the destruction of the heat insulator, it is necessary to provide for its protection. To do this, you can use plaster, ordinary paint and all kinds of panels. These are the methods that experienced builders advise.

The disadvantages of Styrofoam as a wall insulation will let you know if it is worth using it. The protective composition can protect the insulation from ultraviolet exposure, and also make polyurethane foam more attractive. If we consider this minus in more detail, it can be noted that the preservation of the properties of polyurethane foam will require more funds than we carry out work on insulation, which involves materials that do not require appropriate protection. Among other things, not all home craftsmen are able to produce and apply coloring compositions with high quality. As a result, the surface may turn out to be even less attractive than before the refining.

Additional minus

If you decide to choose polyurethane foam, the disadvantages of which for some consumers may be too impressive, then it is worth considering that this material is thermal insulation, which begins to smolder when exposed to fire. This shortcoming is noted by experts. Despite the fact that PPU acts as a slow-burning material, it is not able to cope with fire at 100%. According to the classification, this insulation belongs to the flammability group G-2. This indicates that ignition will not occur when exposed to low temperatures. The flame will go out, the process will stop as soon as the surface of the material can be cooled. If there is a possibility of strong heating or the possibility of ignition of a certain zone of insulation, then in this case polyurethane foam should not be used.

Why you should not choose polyurethane foam for home insulation

Disadvantages of insulation with polyurethane foam, of course, exist. If you decide to produce thermal insulation, then this is important to consider. If the wrong technology is used during the work, this can adversely affect the performance of the building. In order to exclude this, it is necessary to take into account some properties of the described substance. So, PPU has a low vapor permeability - this refers to a rigid variety of material. If the composition is applied to the walls, during processing or other panels, this will certainly lead to dampness on the internal surfaces and in the structure. Dampness and mold can be mentioned as consequences, but if freezing occurs, then the supporting elements will constantly collapse. This point is often noted in their reviews by experienced builders.

The need for fire protection

If you decide to purchase polyurethane foam, the disadvantages of customer reviews should be described in detail to you. After all, it is the negative moments that people notice in the first place. Thus, it is necessary to be prepared for the fact that over time the structure will lose its heat-insulating qualities, at best, they can only decrease. Not only the aging of the material leads to this result, but also temperature changes, as well as exposure to ultraviolet radiation. Quite often, when the spraying method is used, this provides protection from exposure to open flame. If there is no desire to create an additional fire hazard, then appropriate safety measures must be taken. They also become a source of additional expense, which does not always suit consumers.

Minus: the need to take into account the strength of the structure

Polyurethane foam, the shortcomings, reviews of which were analyzed in the article, provides for the need to correctly determine the strength of the structure. This is true in the case when the work involves blowing thermal insulation into the space between the walls. After that, the structure begins to expand, and subsequently the foam can cause destruction. Owners of private houses do not always have the opportunity to make correct calculations.

Why do consumers sometimes refuse to use polyurethane foam

If you decide to use PPU, the shortcomings, reviews of the material should be appreciated by you. So, it is undesirable to use it for insulation inside the building. This can cause a shift to the side of the room. In this case, the wall begins to freeze, the resulting dampness causes the spread of mold, and then the wood begins to rot. In this scenario, the walls remain damp even in summer, which negatively affects the microclimate of the premises. Experts advise, if it is not possible to use analog materials, to use semi-rigid polyurethane foam. In this case, a layer with a thickness of 30 millimeters will be quite enough.

PPU - polymer No. 1 in the world!

The material belongs to the class of gas-filled plastics or, as they are also called, foams. Among the latter there are also resole, urea, polystyrene and other varieties.

Polyurethane foam was first synthesized in 1937 in Germany. Since then, it has found wide application in various fields of activity. One of the main directions is as a thermal insulator having a closed porous structure. PPU has the lowest coefficient of thermal conductivity in comparison with analogues and minimal moisture absorption.

The popularity of polyurethane foam is due to the fact that it can be obtained directly at the place of insulation by mixing liquid components. As a result of a chemical reaction, foaming of the mixture occurs.

The foamed material is 85-90% composed of an inert gas phase. The initial components for its production are polyol and polyisocyanate, which are processed on specialized equipment for polyurethane foam.

PPU equipment of the FOAM series

Applications for polyurethane foam

Polyurethane foam is obtained by two main methods:

spraying with the help of special PPU equipment on the surface directly on the object;
pouring on equipment for the production of polyurethane foam in the production of molded products in the workshop.

Polyurethane products have a wide range of applications: automotive, furniture and design industry, building renovation, hydro and thermal insulation of enclosing structures, insulation of refrigeration equipment, isothermal vans and much more.

Read more about polyurethane foam production methods:

Areas of application for polyurethane foam:

Construction of prefabricated industrial and civil facilities (sandwich structures);
Construction and overhaul of residential buildings, individual houses, cottages (insulation of external walls, foundations, internal insulation of roofs, window openings, doors, etc.);
Industrial and civil construction (external heat and waterproofing of roofs with rigid sprayed polyurethane foam);
Pipeline transport (thermal insulation of fuel oil and oil pipelines, highly efficient insulation of low-temperature pipelines at chemical facilities under a pre-assembled casing);
Heating networks of settlements (thermal insulation with filling PPU of hot water supply pipelines during a new laying or during a major overhaul);
Refrigeration equipment (thermal and cold insulation of domestic and commercial refrigerators and freezers, warehouses for food and agricultural products);
Transport refrigeration equipment (thermal insulation of refrigerated trucks, railway refrigerated cars of the "thermos" type);
Radio and electrical engineering (giving vibration resistance to various electrical devices, hydroprotection of contact connections);
Automotive industry (molded parts of the interior of a car based on elastic, semi-rigid, integral, thermoformed polyurethane foams);
Furniture industry (manufacture of upholstered furniture (foam rubber), cabinet and decorative elements from rigid polyurethane, varnishes, glue, coatings, etc.);
Light industry (manufacture of synthetic leather and products, duplicated fabrics, etc.);
Car building and aircraft building (molded elastic products with increased fire resistance, noise and heat insulation based on special grades of raw materials);
Mechanical engineering (products made of thermoplastic polyurethanes, as well as special grades of PU and polyurethane foam).

Much of the above can be achieved with NST's state-of-the-art PU foam equipment: PU foam sprayers and PU foam casting equipment.

We are ready to transfer technology to you, install and set up equipment for the production of polyurethane foam, help you select the necessary raw materials: components for pouring and components for spraying polyurethane foam, equip you with knowledge and skills, in a word, do everything so that you can set up your own production.

Physical and mechanical properties of rigid polyurethane foams:

PPU products and chemical compounds:

Advantages of polyurethane foam as a heater

Polyurethane foam is considered one of the best heaters due to a set of high installation and operational qualities. The structure of polyurethane foam is cellular, filled up to 90% with gas. It provides the insulation with low weight, eliminating excessive load on the thermally insulated object.

The cured polymer has a thermal conductivity of 0.020-0.035 W/(m·K), which is better than that of mineral wool and gas glass. Unlike expanded polystyrene, such products are resistant to all chemical environments, moisture, and external factors. Polymerization prevents the corrosion process, so the pipeline system insulated with polyurethane foam does not rust. At the same time, its moisture absorption is extremely low.

From the point of view of fire safety, this polymer has no equal. The material is non-flammable, self-extinguishing, does not spread smoke. According to environmental standards, it is completely harmless. Serves as a heater for at least 30 years.

Due to the high adhesive strength, it is not necessary to use fasteners or adhesives - the polyurethane foam sprayed with the help of special equipment adheres securely to the surface. At the same time, it is possible to insulate a surface of any geometric shape, slope and size.

Polyurethane foams also provide high acoustic insulation, so they can also be used as sound protection.

The customer can independently choose a system of liquid components, on which the density of the finished PPU thermal insulation layer depends.

Foamed polyurethane is used for insulation of industrial and civil facilities made of concrete goods, bricks, foam and gas blocks, wood, metal and other materials. Due to the seamless application of the composition, there are no so-called cold bridges through which heat escapes from the room.

Thermal insulation with polyurethane foam

If the ingredients (isocyanate and polyol) are mixed with air, then a fine aerosol is formed, which is applied to the surface. This process is called polyurethane foam spraying. To do this, you must use a spray gun (shown in the photo below in operation and large).

The work is very similar to painting with a spray gun: the operator moves along the surface that needs to be protected with thermal insulation (whether it be a wall, floor, ceiling or even a pipe).

polyurethane foam insulation technology

PPU spraying technology is currently one of the most popular ways to quickly insulate surfaces. With the help of PPU equipment and a spray gun, liquid components are positionally supplied in the form of an aerosol, which passes through the stage of expansion and solidification in a few seconds.

Insulation using polyurethane foam significantly saves money on the transportation of materials, since the production of polyurethane foam can be carried out on the required scale right on the construction site.

Unlike other methods of insulation, polyurethane foam spraying has undeniable advantages:

dew points are excluded, where standard moisture is collected, due to the ideal filling of all cracks, even in hard-to-reach places;
adhesion comparable to professional building adhesives;
the sprayed layer does not leave seams, joints;
cooling of the material is weak, due to the diffusion process of cold air penetration (gradual cooling of the gas in the cells).

Such polyurethane foam insulation creates the effect of a thermos. In addition, high sound insulation is provided. The only thing - you need to provide protection from UV rays.


Facade for cladding

Hangar, inside view	attic floor

heating main

roofs

Polyurethane foam is a highly efficient, technologically advanced, high-quality, affordable and unique in its characteristics heat-insulating material.

Pouring polyurethane foam

If the ingredients are mixed without air access, then a monolithic, even jet is formed, which can be injected into a limited cavity. This process is called pouring polyurethane foam. To do this, you must use the filling head (shown in the photo below in operation and large).

A distinctive feature of this technology is efficiency. It is enough to cover the bottom of the mold with a mixture of ingredients, and after 20-25 seconds the composition increases in volume, filling the entire space. Another distinguishing feature is the ability to obtain products of any relief.

Thanks to this, the polyurethane foam filling technology allows the production of a wide range of different products:

heat-insulating shells;
plates, sandwich panels, panels with cladding, thermal panels;
thermolars, elements of refrigerators;
graters, baguettes, stucco;
furniture elements;
bee hives;
elements of air ducts and ventilation systems ...

And much more!


Shells and furniture decor in molds

Construction graters	Thermal insulation boards

shells	half cylinders

Slab with cladding (roof element)	Window leaf (element of the ventilation system)

Panel with clinker tiles

Another promising area is the production of insulated polyurethane beams, which has long been known abroad. Polyurethane foam is poured between two boards, which, foaming, “seams the boards together”. Subsequent processing on the machine gives an imitation of logs. Advantage: such a 150 mm thick log corresponds to a real 800 mm thick log in terms of thermal conductivity! But a house built from such a bar is lighter, cheaper and warmer!

Polyurethane for pouring molds

When pouring polyurethane foam, in contrast to the spraying technique, not only a pumping station is required for mixing the components in the pouring head, but also molds in which the process of giving the desired look to finished products takes place. With the help of molds, shells for pipes, facing sandwich panels, decor and furniture details, skirting boards, etc. are made.

The technology for the production of insulation involves pouring a thin layer of polymeric raw materials, after which the mold is tightly closed. It takes up to 20 seconds to increase in volume and harden, after which it is possible to start the process of PPU insulation - the installation of molded products.

So, by pouring polyurethane foam, it is possible to obtain any product. The main thing is to choose the right components and mix the composition with high quality. This will provide the NST equipment. Our company also supplies the necessary molds.

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