Technical characteristics of polyurethane foam and its use as insulation. Comparison of polyurethane foam with other insulation materials and its advantages

Conscientious owner own home He always regards the issues of insulating his home as a priority. And this is an absolutely correct position. Well-planned and high-quality thermal insulation performs several important functions at once. It significantly reduces the heat loss of the building, which makes it possible to create an effective heating system in a residential building with minimal energy costs. Thermal insulation helps well on hot summer days - the house will not be hot, and the air conditioning units will not work with excessive load. And, finally, insulation of all the main elements of the structure is the key to their long-term operation, reducing the level of destructive external influences on the building materials of walls, ceilings, and foundations.

However, it is also necessary to remember 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 - some consider it a material with virtually no shortcomings, and there are those who subject it to merciless criticism. Let's try to understand this issue - polyurethane foam insulation, pros and cons, by somewhat summarizing and systematizing information from numerous construction sites and forums.

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

Foam rubber is familiar to everyone - this is also one of the types of polyurethane foam

Of course, for insulation building structures other types of polyurethane are used, but the basic one chemical composition and the principle of obtaining the material remain the same. Feature all polyurethane foams – high gas content, reaching 90% of the total volume of the frozen mass.

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

When insulating certain building structures, ready-made thermal insulating polyurethane foam parts can be used, for example, panels, blocks, semi-cylinders (pipe shells), etc. However, the greatest demand is for 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 harden. Thus, in essence, the preparation of the required composition occurs directly at the site of insulation work.

For large-scale work, two-component compositions are used. As a rule, modern technology involves using a polyol as component “A”, and polyisocyanate as “B”.

Barrels with components “A” and “B”

Mixing these components with the participation of a small amount of water leads to a polymer synthesis reaction with active gas release (in 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, all other conditions being equal, 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 advantage for polyurethane foam with closed cells, precisely as an effective insulation material.

Some professional high-quality systems use freons as a foaming agent.

At the household level, as well as for carrying out operations limited in area and volume (filling cracks, small openings, carrying out repair work etc.) more often one-component polyurethane foam compositions are 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 hardening, contact with oxygen in the air and water is required (wetting the surface and water vapor contained in the air). The result is a porous foam structure, the cells of which are open.

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

The gas involved in forced foaming, freon, gradually evaporates and is replaced by ordinary air, and such polyurethane foam cannot compete with closed-cell polyurethane foam in terms of thermal conductivity. It also loses in strength and resistance to external influences. Therefore, it is not worth seriously considering such compositions as the main ones for insulating a building - they have their own, and very popular, scope of application. The only criterion by which such an open-cell structure wins is noise 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(spray foam)
Thermal conductivity coefficient, W/m ×°С	0.019 ÷ 0.035	0.025 ÷ 0.045
Number of closed cells	More than 90%	Less than 50%
Expansion (rise of foam) compared to the 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 to apply polyurethane foam 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.

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).

Special technological installations are used for spraying. The layout of the complexes may be different, but in any case, the process boils down to the fact that components “A” and “B” are taken from standard containers or built-in reservoirs, pre-filled before starting work. Further, under the influence 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 at the final stage - in the mixing chamber of the gun, and then under high pressure through the nozzle the liquid mixture reaches the surface to be insulated. In fact, the main reaction of polymer synthesis, with the release of heat and a large amount of carbon dioxide, leading to abundant foaming, occurs already on the treated surface.

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

Video: insulating walls by spraying polyurethane foam

The control elements of the process plant allow you to precisely regulate the percentage of components in the mixture - this largely determines performance the resulting coverage. The outlet pressure and the maximum flow rate of material at the gun nozzle can be adjusted.

Despite the apparent simplicity of the technology, it has a lot of subtleties that only experienced specialists know. Carrying out spraying yourself, even if you can 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” who offer their services in this area also often suffer from low professionalism. Buying your own machine for spraying polyurethane foam does not at all mean immediately becoming a qualified specialist, in direct analogy with the fact that buying a car cannot immediately make the new owner an experienced driver. By the way, in Europe, the operator of a polyurethane foam spraying installation belongs to the category of highly qualified workers; training in this specialty even takes more than one year, and during the course of work, at least once every 6 months, it is considered mandatory to undergo control certification. So, when choosing a contractor to insulate 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 from an unknown private owner.

The leader in the production of equipment for spraying polyurethane foam 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 the production of polyurethane foams, the products of the BASF concern deserve maximum marks. This can also be taken into account when choosing a work manufacturer, having familiarized yourself with its technical equipment.

The second option for insulating building structures with polyurethane foam is to pour the mixture into cavities specially left for this purpose. A striking example - frame houses, 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 on a wall. Mixing is carried out in a special chamber of the gun, from where the mixture is already supplied to the outlet, into the supply pipe. The equipment can be used the same as for spraying, only with a certain reconfiguration of parameters. However, for 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 (mold) before the active change in the structure of the composition begins.

In the structure filled with foam, holes are left or made in advance for inserting the supply tube into the cavity, as well as for visual monitoring of the filling level. The qualification of the master here is great value– you need to have a good understanding of the characteristics of the mixture being prepared: its intended volumetric expansion, the time of complete volume expansion 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. Full visual control in such situations is, as a rule, impossible, and the mistakes made can then be identified only during the operation of the building or with the help of special equipment - a thermal imager.

To insulate external enclosing structures, only polyurethane foam with a closed cell structure is used. To create soundproofing barriers in internal walls or ceilings, it is permissible, from an economic point of view, to use cheaper open-cell polyurethane foam.

Video: a clear example of filling a cavity in 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 present a table with the main characteristics of closed-cell material declared by manufacturers, and then we will analyze the main parameters in more detail.

Main characteristics of polyurethane foam	Indicators
Compressive Strength (N/mm²)	0.18
Flexural strength (N/mm²)	0.59
Water absorption (% volume)	Max. 1 ÷ 3
Thermal conductivity (W/m ×° K)	0.019÷0.035
Closed cell content (%)	up to 96
Foaming agent	CO₂
Flammability class	B2
Fire resistance class	G2
Application temperature, not less	+10 °С
Application temperature	from -150°C to +220°C
Application area	Thermal and waterproofing of residential and industrial buildings, containers, cars, watercraft, wagons
Effective service life	30 ÷ 50 years
Moisture, aggressive environments	Stable
Ecological cleanliness	After complete polymerization it is safe. Approved for use in residential buildings. Used in the production of food refrigerators
Loss of flow 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 considered one of the most reliable thermal insulators. True, at times it is credited with absolutely “fabulous” properties, down to a record low thermal conductivity coefficient of 0.017 W/m×°C.

It’s not even worth talking about 0.017 - it’s simply unrealistic. But the figure of 0.20 is found in publications quite often. Is it really?

Talk about such high rates thermal resistance This is possible only with absolute adherence to all technology requirements and the use of the highest quality materials and equipment. 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 is the foaming agent. r141b, which in the majority 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 a more realistic indicator, but even for this 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 ban of which has already been mentioned above.

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

If systems with a closed cell structure and a foaming agent based on a mixture of freons such as Solkane® 365/227 are used, with unconditional compliance with all the requirements of the application technology, then it is realistic to reach a figure close to 0.026 W/m×°C. Unfortunately, in our conditions such systems are practically not used due to their high cost.
If systems are used in which water is used as a foaming component (the most typical case), then best case scenario 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, a polyurethane foam coating with an open cellular structure, the lower limit is 0.037 W/m×°C. This, again, is in theory, since the porous structure of such polyurethane foam absorbs moisture quite abundantly, and 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 very high-quality materials or spraying equipment, violation of technological rules, etc.) leads to the fact that in reality the coefficient increases 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 the closed cellular structure of polyurethane foam, diffusion of freon or carbon dioxide occurs with their weathering and gradual replacement with ordinary air. Therefore, the thermal insulation qualities may decrease.

In general, even 0.030 and even 0.036 is quite a decent indicator for quality thermal insulation material. But you still shouldn’t count on an 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 respects we can agree with this, but still with reservations. Not every polyurethane foam has such outstanding features, and it does not “adhere” equally to all materials.

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

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

It is also absurd to say that polyurethane foam has obviously higher adhesion than any other compositions - there are primers, varnishes and paints that adhere perfectly to galvanized metal, and in the case of spraying polyurethane foam, 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 note on this matter - we can talk about high adhesion only if we are talking about closed-cell polyurethane foam. There are known cases when the applied layer of open-cell polyurethane foam simply flew around even under the influence of its not very heavy weight.

The only thing we can completely agree with in this aspect is that the adhesive properties of polyurethane foam are such that the installation of the insulating layer definitely does not require additional materials and fasteners. This advantage is undeniable. But assessing the degree of adhesion is still the job of technologists.

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

This statement can be called controversial. More precisely, it is better to divide it into two concepts - then it will be easier to “put everything in its place.”

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

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 spraying technology makes it easy to apply polyurethane foam to the most complex shapes and at the very hard to reach places. Moreover, the process is practically waste-free (with highly qualified operator), the coating is uniform and seamless, which greatly simplifies subsequent operations, and without “cold bridges” - the effectiveness of thermal insulation increases sharply.

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

Very long service life of polyurethane foam insulation?

Again, such a statement cannot be called categorical.

First, we can talk about a long service life only when using polyurethane foam with a closed-cell structure. Those inexpensive open cell coatings that will be applied with outside and will become exposed to the most common atmospheric humidity (even without taking into account the likelihood of direct precipitation on them), they are unlikely to last long. In terms of moisture absorption, they are not at all better than that one same mineral wool, and talking about decades of operation is at least naive.

The most terrible 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 service life. The material undergoes destructuring, becomes brittle, brittle, and begins to succumb to abrasion and weathering. Even the highest quality polyurethane foam systems can lose up to 1 mm of thickness per year due to exposure sun rays. This is one of the negative qualities of polyurethane foam, and it must be taken into account when planning thermal insulation work.

Third, not very 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 area, using, for example, low-pressure equipment to apply the outer layer to the walls). And this is again an emphasis on making the right choice contractor.

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

Biological resistance - mold does not appear on polyurethane foam, and mice do not gnaw it?

Again we need to clarify the concepts.

Let's start with mold and other microflora. Colonies are formed where they are created for this purpose favorable conditions. This - high humidity and a certain temperature regime. Thus, if by coincidence the necessary “microclimate” has been 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, could be a closed and poorly ventilated room.

At the same time, with high-quality insulation with closed-cell polyurethane foam, the likelihood of conditions for the development of microorganisms is not so high. Inadequate thermal insulation qualities resulting in constant accumulation of condensation cannot be expected when using even a not so thick layer of polyurethane foam, and a closed cell does not accumulate moisture from the air. But the low probability of the appearance of “nests” of mold or mildew is not at all associated with any special antiseptic qualities of the material - everything follows from its basic thermal characteristics. Well, polyurethane foam itself is certainly not a breeding ground for microflora.

The next issue is the rodent problem. It can be divided into two aspects.

To claim 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 any kind of poison. Just like that, of course, a mouse or rat won’t chew polyurethane foam - it doesn’t represent any nutritional value. But if rodents need to make a passage from the street to a home or to a food storage facility, then a layer of polyurethane foam will not be able to stop them.

Another thing is that in closed-cell polyurethane foam (as well as in extruded polystyrene foam), mice or rats never organize their nests. IN mineral wool or ordinary polystyrene, rodents settle willingly - the conditions necessary for life and reproduction are easily created there. And any cavity in PUF or EPS is a chamber impenetrable to air and moisture, in which normal heat exchange and long-term stay are impossible.

Conclusion - polyurethane foam will not be a barrier for mice or rats, but it will not be a habitat either. Let us repeat - this applies to closed-cell polyurethane foam. In the open-cellular structure, nothing will prevent mice from building 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 cannot 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 and so on. Isn't this an indicator of environmental friendliness?

But here an extremely important caveat follows - all this will 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 hazard groups II and III, which after mixing, reaction and polymerization are converted into completely safe polyurethane foam. However, low quality of the initial compositions, incorrect proportions of supply to the mixer, and other violations of technology can shift the required balance, unreacted components remain, and the resulting spraying can “acquire” very toxic properties in one direction or another. The negative reviews about polyurethane foam found online, that it emits a pungent odor that causes illness, are 100% likely caused by precisely these circumstances.

Another thing is that the spraying process itself requires extremely responsible safety measures. Work must be carried out in special equipment, with mandatory protection of all exposed skin and mucous membranes. Particular attention is provided to ensure respiratory protection. According to existing technological requirements, fully closed masks with forced submission clean air for breathing. By the way, this is another criterion for the conscientiousness and qualifications of the craftsmen. If it is noticed that workers carry out spraying in ordinary clothes, and of all the protective equipment they use only a gauze bandage, this is definitely a “scavenger hunt”. If their manager does not care about the health of his employees, he is unlikely to have a “headache” about the quality of the insulation being performed.

Very often the most environmentally friendly materials They present natural insulation materials - such as moss, sawdust, flax tow, straw, etc. Everything seems to be correct here, except for one thing. Specifically, such materials become a rich breeding ground for microorganisms and insects, and actively absorb a variety of substances from the surrounding air, which may well pose a danger to human health. High-quality closed-cell polyurethane foam does not have such disadvantages.

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

Does using polyurethane foam eliminate the need for vapor and waterproofing?

This advantage is valid only for closed-cell polyurethane foam. Indeed, in both the roofing and wall “pie” (when the material is externally sprayed onto the walls), there is no need to use internal water vapor barrier and windproof waterproof membranes. And this, I must say, is a very significant simplification of everything. general process work and a significant saving effect.

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

Insulating a wooden frame with polyurethane foam is a very dubious undertaking

Spraying polyurethane foam onto a natural wooden frame is not particularly welcome, especially one that has recently been erected, the logs in which have not yet had time to free themselves from excess moisture. If you look at the vapor permeability table, the indicator for sprayed polyurethane foam and coniferous wood across the fibers is approximately the same, about 0.05 mg/m×h×Pa. Polyurethane foam "coat" with certain conditions can “preserve” moisture in the wood, and this is dangerous due to 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 is practically no different in this regard from other insulation materials. When using it, the use of water and wind protection will become a prerequisite.

Is the material fire resistant?

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

If the owner of the house chooses inexpensive material from some eastern manufacturer, then this is most likely G-4 class polyurethane foam. It should be noted that this class includes everything that burns. In such compositions, no flame retardant additives are used at all, or their concentration is frighteningly low. One can say unequivocally about such material - it burns “quite decently”, and it becomes quite difficult to extinguish it. not an easy task. And it not only burns, but also becomes a flame spreader. Unfortunately, modern history is full of cases where, for example, polyurethane foam spraying caught fire due to welding work and burned out completely, which led to deformation and destruction of even strong wall structures. Thus, by purchasing an 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 high-quality compositions can already be classified as category G-3 - the material will not ignite on its own without exposure to an open flame. When the source of fire disappears, the polyurethane foam extinguishes and cokes, preventing the flame from spreading further. Unlike expanded polystyrene, it does not melt and does not flow. Smoldering of the coked material is possible, but even under these conditions the combustion products are not as toxic as when burning polystyrene foam, although they also pose a very serious 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 approximately 3–4 times higher than that of popular G-3 class systems.

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

Consequences of the fire - polyurethane foam prevented the fire from spreading

For example, the photograph shown shows the consequences of a fire that occurred in the room above. The sprayed polyurethane foam on the ceiling burned out and coked, but did not transmit the flame below. At the boundary 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 generally remained intact. In addition to, in fact, low flammability, this was also facilitated by the extremely low thermal conductivity of the material - it does not contribute to the spread of the high temperature necessary for the occurrence of a flame.

So, the publication quite objectively, from the author’s point of view, examined the main properties of polyurethane foam used as insulation. Having become familiar with the advantages and disadvantages of this material, having studied the possibility of inviting truly qualified specialists with high-quality component systems and classy equipment, having roughly calculated the “accounting” 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 insulation materials suitable for this design.

Variety of insulation materials
Will help you choose the right one comparative analysis given in a special article on our portal.

Calculator for calculating the thickness of the insulating layer

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

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

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

Energy prices in Lately are getting higher, and effectively insulating a home is one of the main challenges that homeowners have to solve. One of the latest materials that appeared on the market several years ago is polyurethane foam. This is a coating that is applied in a continuous layer to any (almost) surface. Insulation with polyurethane foam is the most effective.

Types of sprayed polyurethane foam and application technologies

Polyurethane foam is obtained by mixing two components - a diisocyanate and a polyol. Both components individually are toxic, so work is carried out with respirators. By mixing, two toxic substances form a safe polymer - polyurethane - absolutely neutral, which does not react with any substances. Once hardened, polyurethane foam 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 is enclosed in the thinnest polyurethane shell, which gives high thermal insulation performance (carbon dioxide is a poor conductor of heat).

The two components are mixed in a special gun under high pressure. To obtain ideal 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 foam and then harden. This is what insulation with polyurethane foam consists of.

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. It’s worse if there is more diisocyanate - such foam quickly “sits”, then collapses, losing its heat-insulating characteristics. If you overdo it with polyol, the picture is a little better - the foam becomes brittle, but it does its job, even though it has a higher thermal conductivity than stated. This is precisely one of the disadvantages of polyurethane foam insulation - the final result very much depends on the qualifications of the workers and the class of equipment used.

It is possible to mix components in given proportions almost perfectly accurately 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, you will most likely get non-uniform spraying with poor thermal insulation characteristics.

But different equipment isn't everything. Is there some more different types polyurethane foam by cell type and density:

If we talk about prices, the cheapest is lightweight open-cell polyurethane foam. But if we add the need for hydro- and vapor insulation, then in general the price of insulation will not be so low. At the same time, it is still unrealistic to achieve perfect isolation, and it may well turn out that this type PPU insulation will be cold. To help you navigate the prices, we provide approximate prices for different types PPU (material+work):

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

Advantages and disadvantages

Let's start with the advantages:

As you can see, there is 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 also disadvantages:

The main limiting factor in the spread of polyurethane foam insulation is 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 sprayed thermal insulation is installed many times faster in terms of time, gives best result. Overall, if you are planning to insulate your home, this technology is worth exploring.

Application conditions and surface preparation

Even with good adhesion, which is characteristic of polyurethane foam insulation, surface preparation will not be superfluous. First of all, you need to remove everything that is crumbling - and first of all the old paint. Mandatory removal and neutralization are also subject to greasy spots. They shouldn't exist.

Everything that should not be covered with foam should be covered with polyethylene secured with tape. It must be secured carefully, without gaps - it is difficult to remove the foam.

When insulating a roof with polyurethane foam, there are two ways to apply thermal insulation. The first one is to make it permanent continuous sheathing, onto which foam is poured. The second is to make a temporary frame consisting of two parallel planes.

If the outer walls of a building are insulated with polyurethane foam, a finishing finish is assumed. And after cleaning the surface, you need to make sure that you can strengthen it with something - it won’t work with foam. To do this, most often, wooden or metal strips are placed on the walls, to which they are then attached. exterior decoration. This completes the preparation. But applying polyurethane foam is only possible on a completely dry surface, at temperatures above +10°C. There are no other conditions.

Sputtering process

If you have entered into an agreement with a company, a minibus arrives at the appointed time. It contains spraying equipment. To operate a high-pressure apparatus, a voltage of 380 V is required. If you only have 220 V, you usually start a generator that produces the required voltage. A low-pressure apparatus can operate from a 220 V network, but, as discussed below, the quality of thermal insulation will be significantly worse.

Typically, only hoses are pulled into or around the house to supply the foam components to 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 because before hardening the foam components are toxic, and everything else is to protect skin from getting hit by polyurethane foam, which is then impossible to tear off.

The foam is applied from bottom to top, in small portions. Fill everything in without skipping, trying to prevent the formation of shells. As the foam expands, make sure that the layer thickness is no less than the required one. After the foam hardens, the excess can be cut off, but the deficiency cannot be made up for.

Parameters of sprayed insulation

It’s worth saying right away that, as with any other insulation, it is preferable to insulate the walls of buildings from the outside. If , then outer wall will freeze. How many defrosting/freezing cycles it will withstand depends on the material, but rarely will such a house last more than 10 years.

When insulating the outside with polyurethane foam, a final exterior finish is required - the surface has a very unattractive appearance. But there are no problems with freezing of the walls, the building will last a long time.

There are no problems with the roof at all. Roofing materials are designed to withstand repeated freezing, so roof insulation with polyurethane foam can be done from the inside, spraying it directly onto the “underside” of the roofing material or onto the sheathing.

Whether to insulate the house from the outside or from the inside, we figured it out. Now a little about the layer thickness. Insulation with polyurethane foam is usually done large thickness. This is not due to the fact that small is not enough. Usually, just according to thermal characteristics, an insulation thickness of 2-3 cm is required, but they make it at least 5 cm. This is so that under any conditions the dew point ends up in the thickness of the thermal insulation, and not in the wall material. Since polyurethane foam is non-hygroscopic, it cannot get wet, condensation simply does not occur, and excess moisture is removed naturally due to the vapor permeability of the material.

Before purchasing any material, every consumer considers the disadvantages. Polyurethane foam is no exception. Every builder today has heard a lot of information about this material, which is otherwise called polyurethane foam.

Which material to choose

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

Description

Polyurethane foam, the disadvantages of which you should be aware of before starting insulation work, is a type of plastic. Products made 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 entire structure consists of small cells that are well isolated from each other by walls; it is these cells that are filled with gas. The remaining percentage of volume represents the solid part, namely the walls themselves.

The disadvantages of polyurethane foam as insulation are worth considering. Varieties of polyurethane foam are used quite often today; the material is popular among consumers, since it is very simple to manufacture; this can be done 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 required proportions of ingredients are observed, a polymer will be synthesized, which is represented by a hardened foam. If you slightly change the preparation technology, you can get polyurethane foams that 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 the substances, it is possible to obtain polyurethanes that consist of many cells different sizes. Their walls may have different thicknesses, as well as durability.

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 become more familiar with the disadvantages of the material. The main one is the negative impact of sunlight on the surface, which can cause rapid wear of products. In order to prevent 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 recommend.

The disadvantages of polystyrene foam as wall insulation will allow you to decide whether it is worth using it. The protective composition can protect the insulation from exposure to ultraviolet radiation, and also make polyurethane foam more attractive. If we look at this disadvantage in more detail, we can note that preserving the properties of polyurethane foam will require more money than we would need to carry out insulation work, which involves materials that do not require appropriate protection. Among other things, not all home craftsmen know how to produce and apply coloring compositions with high quality. As a result, the surface may turn out to be even less attractive than before upgrading.

Additional minus

If you decide to choose polyurethane foam, the disadvantages of which may be too impressive for some consumers, then it is worth considering that this material is thermal insulation, which begins to smolder when exposed to fire. This drawback is noted by experts. Despite the fact that polyurethane foam acts as a low-flammable material, it is not able to cope with fire 100%. By classification this insulation belongs to the flammability group G-2. This indicates that when exposed to low temperatures no fire will occur. The flame will go out and 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 fire in a certain insulation zone, then polyurethane foam should not be used in this case.

Why you shouldn’t choose polyurethane foam for home insulation

Disadvantages of polyurethane foam insulation undoubtedly exist. If you decide to make thermal insulation, then it is important to take this into account. If you use the wrong technology during the work process, this can negatively affect the performance characteristics of the building. In order to exclude this, it is necessary to take into account some properties of the substance being described. Thus, polyurethane foam has low vapor permeability - this refers to a rigid type of material. If you apply the composition to the walls, when 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, the load-bearing elements will constantly collapse. Experienced builders often note this point in their reviews.

The need for fire protection

If you decide to purchase polyurethane foam, customer reviews should describe the disadvantages in detail to you. After all, it is negative points people celebrate first. Thus, you need to be prepared for the fact that over time the structure will lose its heat-insulating qualities; at best, they may just decrease. This result is caused not only by the aging of the material, but also by temperature changes, as well as exposure to ultraviolet radiation. Quite often, the spraying method is used, this provides protection from exposure to open fire. 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.

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

Polyurethane foam, the disadvantages of which reviews were analyzed in the article, requires the need to correctly determine the strength of the structure. This is true when the work involves blowing thermal insulation into the space between the walls. After this, 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 polyurethane foam, you should evaluate the shortcomings and reviews of the material. So, it is undesirable to use it for insulation inside a building. This may cause a shift towards the room. In this case, the wall begins to freeze, the resulting dampness causes mold to spread, and then the wood begins to rot. In this situation, the walls remain damp even in summer, which negatively affects the microclimate of the premises. Experts advise, if it is not possible to use analogue materials, to use semi-rigid polyurethane foam. In this case, a layer with a thickness of 30 millimeters will be sufficient.

The development of energy saving has a direct impact on the development of new thermal insulation materials and energy efficient technologies. One of these are pipes in polyurethane foam insulation.

In this article, we will understand what a polyurethane foam pipe is and what opportunities the use of these materials on an industrial scale provides.

PPU pipes - what is it?

Pipes in polyurethane foam insulation (PPU insulation)- this is a design made according to the “pipe-in-pipe” principle, i.e. consists of two pipes: the inner working (bearing) and the outer protective (shell), the gap between which is filled with polyurethane foam.

In a nutshell, a polyurethane foam pipe is a steel pipe that has additional protection in the form of a heat-insulating layer, the functions of which are performed by polyurethane foam. A protective waterproofing shell made of polyethylene or galvanized steel extends the trouble-free service life and expands the scope of application.

PPU pipe production technology

The production of polyurethane foam pipes is possible only in factory conditions, where polyurethane foam is sprayed onto a steel pipe, which in turn is covered with a galvanized steel shell or a layer of polyethylene (in a polyethylene shell). The procedure for manufacturing pipes is regulated by GOST 30732-2001. The standard was finally approved and recommended for use only in 2006, so the name of the PPU pipe GOST 30732 2006 is often found. It is worth noting that the standards of the standard apply only to PPU PE. The production of polyurethane foam pipes in a galvanized shell is not regulated;

insulation of pipes with polyurethane foam insulation. It involves applying polyurethane foam to the pipe or packaging it in a polyurethane foam shell. Application of polyurethane foam is a more popular option for pipes in use, because... it becomes possible to insulate already installed pipelines. In addition, insulating pipes with polyurethane foam is a more economical option.

- are a shell made of polyurethane foam, consisting of one, two or several parts (cylinder, half-cylinder, prefabricated elements). Dimensions of the polyurethane foam shell: length 1 m., thickness varies. The use of shells makes it possible to insulate a pipe without the use of polyurethane foam spraying equipment. The installation technology involves fixing the PU shell on the pipe using ties.

Stages of production of polyurethane foam pipes

To understand what determines the high performance properties of pipes in polyurethane foam insulation, let’s briefly consider how their production takes place:

input control. Incoming raw materials and other components are checked for compliance with standards: polyethylene, polyurethane foam system, steel, UEC sensors, etc.;
production of polyurethane foam shell;
installation of a steel pipe in a shell. Also includes installation of UEC conductors;
polyurethane foam filling;
outgoing control. All products must be tested for compliance with norms and standards.

These are the stages of the production cycle that pipes go through at large domestic factories.

The production process is regulated by standards:

Main manufacturers of polyurethane foam pipes

LLC "MTER TsTS" ("Mezhregionteplosetenergoremont TsTS") (Moscow) is considered the leader in Russia in terms of the volume of produced polyurethane foam pipes;

LLC "Tatteploizolyatsiya" ("TTI"), Republic of Tatarstan. It is one of the four largest enterprises producing polyurethane foam pipes in the Russian Federation. The production uses equipment from KWH (Finland), which allows the production of over 1,700 m.p. per day.

Also among the large regional manufacturers are:

LLC "ZTI" (Thermal Insulation Plant), St. Petersburg;

LLC "SKTK" (Moscow);

SZTGK - North-West Pipe Waterproofing Company (St. Petersburg);

Pervouralsk pipe insulation plant (Ekaterinburg);

LenSpetsStal company (St. Petersburg);

LLC "Bizol" (Chelyabinsk);

CJSC "UZTI" ("Ural Thermal Insulation Plant"), Sverdlovsk region, Polevskoy.

The listed factories confirm the quality of polyurethane foam pipes and components with certificates and test reports.

PPU pipe design (device)

Part insulated pipe includes three layers:

main (working) steel pipe. Pipes are used that meet the requirements of GOST 3262-78, 8732-78, 10705-80, GOST 30732-2006, SNiP 3.05.03-85;

thermal insulation material - PPU insulation. Thermal insulation is provided by spraying polyurethane foam. This innovative material differs from traditional insulators (for example, glass wool) by its low thermal conductivity, hygroscopicity, and durability. Thermal insulation material must comply with GOST 30732-2006. In this case, an important requirement must be met - good adhesion to the material of the working pipe and shell. Permissible displacement (axial shift) - 0.14 MPa (t=23°C);

PPU insulation shell. As such, black low-density polyethylene is used (regulated by GOST 18599-2001) or galvanized (regulated by GOST 52246-2004) - steel protective shell(made from galvanized strip). The type of shell is noted when marking the product;

UEC system(This component more advanced types of pipes). PPU pipe with ODK (SODK) is a pipe in polyurethane foam insulation, which is equipped with an operational remote control system.

Installing the UEC makes it possible to receive information in real time about possible defects:

damage to the main pipe;
damage to the shell pipe;
malfunction of the signal wire;
incorrectly installed joints of polyurethane foam pipes (wires are poorly connected to each other).

UEC allows you to monitor the condition of the pipeline in a specific section or along the entire pipeline route.

Note. ODK is mounted in polyurethane foam pipes in a polyethylene sheath. As for pipes encased in galvanized steel, in this case the availability of UEC is discussed with the customer. And the specificity of installing copper control wire is that there are three, not two, signal wires.

Scope of application of polyurethane foam pipes

laying heating networks (hot water supply systems, heating and heating mains);
laying water supply systems and water pipelines;
laying industrial networks;
gas production industry (gas transportation);
oil refining industry (transportation and processing of petroleum products).

Types of pipes with PPU insulation

Wide range of applications and the ability to use different materials to form a protective outer shell pipes makes it possible to manufacture two of the varieties. Information about the purpose and composition of the pipe is contained in the marking. There are types and types:

PPU pipe in a polyethylene sheath (PPU PE pipe). In this case, for protection thermal insulation material polyethylene is used. Designed for installation in underground ductless and channel pipelines. Some manufacturers label this type as St PPU PE pipes, which means that the working pipe is a steel pipe with a polyethylene sheath;

PPU pipes in galvanized casing (PPU pipe OTs). The function of protecting the insulation is delegated to galvanized material, which is wound into a casing (shell, case). They are used for overhead laying of pipelines (aerial laying). In this case, polyethylene is unable to perform protective functions, because is destroyed under the influence of ultraviolet radiation and other external factors. A galvanized steel shell provides better protection in these conditions.

Pipes also differ depending on the thickness of the insulation used in them:

1 PPU- standard type of insulation. Suitable for installation in regions with temperate climate. In this case, the pipes are marked as follows: 1 PPU PE (in a polyethylene sheath) or 1 PPU OTs (in a galvanized sheath);

2 PPU- reinforced type of insulation. Designed for areas with cold climates. Products are designated 2 PPU PE or 2 PPU OTs.

PPU pipe marking

Marking example:

PPU pipe st. 57x3-1 PPU-PE with ODK GOST 30731-2006

It stands for: pipe with polyurethane foam insulator, steel, outer diameter is 57 mm, steel wall thickness is 3 mm, PPU type - insulation of the first type (1 PPU), polymer shell (PE), the pipe is equipped with an operational remote control system (ODC). Manufactured in accordance with the requirements of GOST 30731-2006.

Shaped products for PPU pipes

Installation of polyurethane foam pipes is carried out using shaped products.

The most popular of these are:

steel pipes PPU;
bends, elbows, bends;
PU shell;
heat-shrinkable cuffs (allow you to ensure the tightness of the pipe junction);
PPU pipe supports;

fixed supports. Allows you to ensure the stability of the pipe on a straight section of the heating main;
sliding supports. Used when installing pipes by air (ground) method. Sliding support allows the pipe to move, compensating for expansion caused by external factors.

Such a variety of shaped elements makes it possible to install systems of varying complexity and perform reliable connection pipes to each other.

PPU pipe sizes

Metrological parameters of polyurethane foam pipes (dimensions, diameters)

Metrological parameters of polyurethane foam pipes (gradation by type)

Pipes in PPU insulation made of polyethylene (PE)

Size range. Outer diameter from 32 mm to 1020 mm, inner diameter 25-1000 mm, wall thickness 2-11 mm, PE shell diameter for 1-2 types of polyurethane foam 90-1200 mm, polyethylene shell thickness 3.0-14.9 mm.

Pipes in polyurethane foam insulation made of galvanized steel (OTs)

Size range. Outer diameter from 32 mm to 530 mm, inner diameter 25-500 mm, wall thickness 2-7 mm, diameter of the OC shell for 1-2 types of polyurethane foam 100-710 mm, thickness of the galvanized shell 0.5-0.7 mm.

Technical characteristics of polyurethane foam pipe

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Performance characteristics of polyurethane foam pipe

Polyurethane foam pipes are of interest to housing and communal services, industrial and oil refining enterprises; they are unlikely to be useful in private households.

Cost of PPU pipes

For those wishing to buy or get an idea of the cost of polyurethane foam pipes and shaped elements, we provide approximate prices

Studying products different manufacturers, it is not difficult to notice that on the website of each of them there is a price list for polyurethane foam pipes. However, it should be understood that this price is not final, because it is derived from many factors and is constantly being revised. In the case of significant volumes of purchases, the price is subject to negotiation.

Advantages of pipes with PPU insulation

polyurethane foam insulation of pipes can significantly reduce heat loss. The maximum heat loss is only 4%, while steel pipes with traditional thermal insulation have heat loss in the range of 20-25%;

high degree of reliability;

reduction of heat loss during coolant transfer by 35-40%;

resistance to temperature conditions. Applicable in the range of external temperatures from -80 to +130 °C;

resistance to moisture;

non-corrosion without additional treatment;

high laying speed. Installation of polyurethane foam pipes is carried out above-ground, underground and channel methods. Underground channelless installation to a depth of up to 1 m is possible. This installation method involves installing the pipeline directly in the trench; there is no need to use reinforced concrete trays;

environmental Safety;

rot resistance;

significant reduction in costs for construction, maintenance and repair of heating mains;

the ability to monitor the state of the system (due to the presence of an online remote monitoring system);

anti-vandalism. Thermal insulation from polyurethane foam pipes is almost impossible to steal and reuse;

increasing the service life of the heating main.

In conclusion, we note that pipes with PPU insulation are the new kind insulated pipe material, which has a significant list of advantages, is distinguished by a reasonable price/quality ratio and has long term operation.