Warming with polyurethane foam - advantages and disadvantages. Equipment for polyurethane foam Calculator for calculating the thickness of the insulation layer

Polyurethane foam is the best option for insulation for any structures (both frame and brick, block, panel, wood) that do not experience serious mechanical stress.

This material can be used to insulate the inner walls and the surface outside the facades of the house. When insulating the facades of a wooden, brick, or aerated concrete house, outside the polyurethane foam insulation, a frame is created for sheathing, on which the facade panels are fixed, or similar facing materials - lining, siding, decorative concrete.

Foam polirutan has good adhesion (adhesion to the coating), which allows you to insulate any inclined surfaces. This determines the popularity of polyurethane foam insulation for the roof of the house, when arranging the attic floor from the attic.

1.3 Thermal insulation of pipes

In the thermal insulation of pipes, ventilation shafts and elements of production lines, PPU is one of the main materials. Polyurethane foam insulation can be used for pipes, the temperature of the working environment in which is from -180 to +120 degrees.

The only caveat is that the diameter of the pipes must be large: it is difficult to use PPU for too thin pipe sections.

1.4 Repair work and construction of frame houses

Due to the liquid form of the material, any cavity can be filled with this insulation. PPU foam is the only insulation that can insulate the interior of hollow walls made of concrete or brick, without violating the integrity of the house structure.

Polyurethane foam is the main thermal insulation material used in the construction of a timber frame house. The walls of a frame house are wooden formwork filled with insulation - this technology allows you to build a cozy warm house in the shortest possible time.

2 Technical characteristics of PPU

As already mentioned, in terms of the effectiveness of thermal insulation, insulation with polyurethane foam has no analogues among widespread heaters.

There are two types of polyurethane foam insulation - with a closed and open cellular structure. The number of closed cells in closed-cell polyurethane foam is 92%, in polyurethane foam with open cells - 50%. These materials differ not only in terms of density and strength characteristics, but also in terms of technical properties.

Consider the main technical characteristics of PPU closed cell heaters:

Thermal conductivity coefficient - 0.019 - 0.025 W / mk;
Vapor permeability coefficient - 0.04 mg / mchPa;
Density - from 18 to 300 kg / m³, depending on the application technology;
Moisture absorption from volume at full immersion in water for 24 hours - 1%;
Flammability class - G2 (hardly combustible materials);
Temperature range from -180 to +130 degrees.

Sprayed open-cell polyurethane foam has the following technical characteristics:

Thermal conductivity coefficient - 0.025 - 0.03 W / mk;
Vapor permeability coefficient - 0.08 mg / mchPa;
Density - from 8 to 20 kg / m³;
Moisture absorption from the volume when fully immersed in water for 24 hours - 15% as in.

The flammability class and temperature regime of an open polyurethane foam is similar to a closed-cell insulation.

As you can see, in virtually all technical characteristics, closed-cell polyurethane foam is better than open-cell polyurethane foam. In view of this, open polyurethane foam is used extremely rarely for thermal insulation purposes.

The only advantage of the material with open cells is its high noise-suppressing properties, thanks to which such polyurethane foam is popular in sound insulation of residential and industrial premises.

2.1 Advantages and disadvantages

According to reviews, sprayed insulation has only one significant drawback - high cost, which limits the growth in popularity of this material in private insulation.

Among the indisputable advantages of polyurethane foam insulation, which justify the high costs of insulating a wooden or brick house, the following factors can be distinguished:

Efficiency - according to this parameter, PU foam insulation is significantly better than thermal insulation by any other material;
Minimum weight - the mass of one cubic meter of polyurethane foam is about 50 kg, such insulation does not exert a serious load on the supporting structure of the roof of a wooden house, which allows it to be used to insulate old houses;
Reliability of adhesion to the surface - adhesion of polyurethane foam to the walls of a wooden house is 1.5 kg / cm², with concrete walls - 2.5 kg / cm². This indicator indicates that the frame that holds the mineral wool is more likely to collapse than polyurethane foam insulation will fall off from the wall;
Ease of installation as in the case of - sprayed technology is much easier and faster than gluing or installing insulation in a supporting frame;
Moisture and vapor permeability - after drying, the polyurethane foam forms a monolithic material that has neither joints nor microcracks, such a heater does not allow steam to pass through and does not absorb moisture even after long-term immersion in a liquid;
Versatility - with the help of polyurethane foam, you can insulate surfaces of any shape - pipes, facades, walls of a wooden frame house;
Durability - polyurethane foam is a chemically resistant material, it is durable, and is not afraid of rodents and microorganisms, which determines the over 30-year service life of such thermal insulation.

3 Comparison of polyurethane insulation and polystyrene

The closest analogue of polyurethane foam in terms of technical characteristics, among the widespread heaters, is expanded polystyrene.

Expanded polystyrene is a panel insulation made by foaming and subsequent extrusion of polystyrene granules. Expanded polystyrene has a number of advantages, due to which the use of this insulation is more preferable than the use of the rest of the plate thermal insulation.

Expanded polystyrene is effective - the thermal conductivity of the material is 0.028 W / mk;
Expanded polystyrene is quite easy to install - it is mounted on the surface of facades and walls using an adhesive composition;
Expanded polystyrene does not absorb moisture (0.02% by volume), and is a vapor-proof material;

In comparison with sprayed PU foam, expanded polystyrene is somewhat limited in functionality, since only flat surfaces can be insulated with it. Expanded polystyrene is not used for arranging thermal insulation outside pipes, ventilation ducts, internal insulation of the walls of a wooden frame house, and surfaces with complex geometry.

However, expanded polystyrene has one key advantage - it is impossible to carry out insulation with polyurethane foam with your own hands due to the fact that for the production of PU foam, special equipment is needed at the workplace, while expanded polystyrene can be purchased and installed without any problems.

Of course, you can use small cylinders with polyurethane foam, but for the insulation of large surfaces - facades, walls of a wooden house, outside the foundation, etc. It is unprofitable to do this, due to the increase in the cost of insulation per square meter.

If you want to perform insulation with polyurethane foam, you will have to hire a team that will do everything quickly and efficiently. The current price of PPU thermal insulation of facades is 1500-1700 rubles per square meter of the surface to be insulated, taking into account the cost of the material.

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 classical insulation (mineral, basalt wool, foam, glass wool, extruded polystyrene foam). Reviews of PU foam insulation confirm the effectiveness, for example, a 2-cm layer of polyurethane foam is comparable in efficiency to 20-cm mineral wool.

What are the opinions?

“According to reviews, insulation by means of polyurethane foam 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, because it is resistant to biodegradation, inert to chemical environments and high strength, which makes it indispensable for thermal insulation of such buildings. "

Alexander Boyko, Moscow.

“Reviews of 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 on payment for energy resources. I have my own service station, with such a building, it should be remembered that not every insulation is able to maintain its characteristics in contact with gasoline vapors and engine oil. I opted for polyurethane foam as it is resistant to chemically aggressive environments. "

Vasily Arkadievich, Samara.

“Polyurethane foam is a versatile 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 creating a uniform layer for structures with a complex configuration (attic walls and ceiling). "

Igor Vlasov, Ufa.

“Reviews and opinions about PU foam 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.

“As a person who has been working with a liquid heat insulator for a long time, I would like to say 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.

A review of polyurethane foam insulation indicates the possibility of using it for buildings constructed from various materials. Polyurethane foam has high adhesion, which ensures 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 inexpedient 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 and the use of fasteners;
light weight;
small layer thickness with its energy efficiency;
application for external and internal insulation;
uniformity and integrity avoids the formation of cold bridges.

Polyurethane foam is easily applied to various surfaces, suitable for structures with complex configurations.

The main disadvantages are the high price and the impossibility of performing work on thermal insulation 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.

Before purchasing any material, each consumer considers the disadvantages. Polyurethane foam is no exception. Today, every builder has heard a lot of information about this material, which is also called PPU.

What material to choose

If you have ever thought about insulating your home, then you probably paid attention to this option as thermal insulation. Perhaps it is he who will be the best solution, because along with the shortcomings he 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 contains a gaseous substance, which is contained in a volume of 85 to 90%. The entire structure consists of small cells that are well insulated from each other by walls, and it is these cells that are filled with gas. The remaining percent of the volume is 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 it, it can be done directly at the construction site. In this case, the two liquid components must be mixed, after which they 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 cooking 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 insulating buildings made of reinforced concrete or bricks. As for the third varieties, they are widely used for pipelines. Thus, depending on the proportions of substances, it is possible to obtain polyurethanes at the output, which consist of many cells of different sizes. Their walls can have different thicknesses and strengths.

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 familiarize yourself with the cons of the material. The main thing 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 you should use it. The protective composition can protect the insulation from the effects of ultraviolet radiation, and also make the polyurethane foam more attractive. If we consider this minus in more detail, then it can be noted that preserving the properties of PU foam will require more funds than we will carry out insulation work, where materials that do not require appropriate protection are involved. Among other things, not all home craftsmen know how to produce and apply dye compositions with high quality. As a result, the surface may turn out to be even less attractive than before the refining.

Additional disadvantage

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, when exposed to fire, begins to smolder. This drawback is noted by experts. Despite the fact that PPU acts as a slow-combustible material, it is not able to cope with fire at 100%. According to the classification, this insulation belongs to the G-2 flammability group. This indicates that no ignition will 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, you should not use polyurethane foam.

Why you shouldn't choose polyurethane foam for home insulation

The disadvantages of polyurethane foam insulation undoubtedly exist. If you decide to make thermal insulation, then this is important to consider. If you use the wrong technology in the process of carrying out work, then this can negatively affect the operational characteristics of the building. In order to exclude this, it is necessary to take into account some of the properties of the described substance. So, polyurethane foam has low vapor permeability - this refers to a rigid type of material. If you apply the composition 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 the consequences, but if freezing occurs, then the bearing elements will constantly collapse. This moment is often noted in their reviews by experienced builders.

The need for protection from fire

If you decide to purchase polyurethane foam, customer reviews should describe the shortcomings in detail. After all, it is the negative moments that people note 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. This is the result not only of aging of the material, but also of temperature changes, as well as exposure to ultraviolet radiation. Quite often, the spraying method is used, this provides for protection from the effects of open fire. If there is no desire to create an additional fire hazardous situation, 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 shortcomings, reviews of which were analyzed in the article, provides for 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 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 apply PPU, the shortcomings, feedback on the material should be appreciated by you. So, it is undesirable to use it for insulation inside the building. This can cause movement towards the room. In this case, the wall begins to freeze through, the resulting dampness causes the spread of mold, after which the wood begins to rot. In this situation, the walls remain damp even in the 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 enough.

Roof insulation is a process that automatically transfers the attic from the category of non-residential to residential. At the same time, the area of housing increases by almost the size of a full floor, and such an increase should not be neglected. helps you create another living space effortlessly.

It is worth mentioning other good reasons for insulating the roof - for example, eliminating its heating in winter, which eliminates the formation of ice, icicles, and on warmer days - snow from the roof. Thus, the procedure is necessary and useful. You can read more about self-insulation of the roof in.

One of the most effective insulation materials is deservedly considered polyurethane foam (PPU).

Let's consider the insulation of the roof with polyurethane in more detail.

First of all, it is - two different materials, both in chemical composition and mechanical properties. If we compare PPU with foam plastic, then the most conspicuous difference will be hardness.

Styrofoam(expanded polystyrene) practically lacking flexibility, at the slightest bends, it can break, while PPU allows practically any deformations without losing the integrity of the structure.

Moreover, polyurethane foam has elasticity, the ability to take its previous shape after stress relief. Such a difference in mechanical characteristics with more or less similar heat-conducting, noise-absorbing and other parameters puts the use of these two materials at different stages.

Styrofoam is cheaper, it can be used in places where it will not experience any physical exertion. In addition, a certain stiffness of the foam in some cases is an advantage that greatly simplifies the installation process.

PPU is a material that has several types, different density, which creates many subspecies with different characteristics. All varieties have one main advantage - practically full resistance to water, which is the most significant plus for heaters.

Types of polyurethane foam

Polyurethane foam is a type of plastic made from two main components. The reaction of these components creates a material, the properties of which can change with different ratios of the starting materials. Distinguish soft varieties Polyurethane foam, with a density of 5-40 kg / m 3, and tough varieties- 35-80 kg / m 3

The variety of types has caused widespread use of the material, from furniture (known to all foam rubber) to insulation in construction. One of the most beneficial properties, actively used in industry is the possibility of spraying the material right at the place of use, bypassing the stages of manufacturing, storage, transportation, installation, fitting, etc.

This property very favorably distinguishes polyurethane foam as insulation, which is applied directly to the surface to be treated with practically no preparatory operations, forming a highly effective heat-retaining layer that does not react to moisture, does not change its qualities over time, does not interact with biological organisms and non-swelling.

Alternative types of roof insulation

In addition to PPU, the following are used:

Styrofoam.
Minvata.
Glass wool.
Ecowool.
Izover.
Expanded clay.
Cellulose, etc.

The list of all types of insulation suitable for use on the roof is quite large, but only a few types are used - mineral wool, isover, ecowool and some others. The reasons for this are the prices and unsatisfactory characteristics of a number of materials.

For example, ability to absorb water for insulation unacceptable, since all heat-conducting qualities disappear from this. For example, glass wool has such problems. In addition, a number of materials are prone to caking, which changes the layer thickness and decreases performance.

Note!

Of the above, the most preferable is basalt mineral wool, as the most effective material in all respects. But you cannot work with it without creating protective layers. hydro and vapor barrier, the so-called roofing cake, without which the material gradually loses its properties. We recommend that you read the article on the topic - "with your own hands".

In general, reliable insulation from water vapor or splashes allows you to use any insulation, if the choice is small, you just need to know its strengths and weaknesses and take them into account when installing.

Do-it-yourself roof insulation with polyurethane foam

Consider the process of insulation with liquid polyurethane foam, as an almost ideal option for today. The insulation technology is quite simple, but it has many nuances, which we talked about in.

Available for sale special kits for spraying polyurethane foam, consisting of two containers with initial reagents, which are mixed directly in the process of spraying in the working head.

The reaction takes place quickly enough, and you cannot mix in any other way.

Surface preparation is simple and does not require any complicated operations. You just need to clean it from debris, dust and dry it, if necessary. There is no need for preliminary cutting off of the insulation with waterproofing membranes, since the surface of the material itself excellent insulator that does not react to water vapor or splashes.

Warming roofs with polyurethane foam from within, and PUF is applied in gaps between rafters... The material expands in the course of the reaction, gas bubbles appear in it, imparting the required heat-insulating ability. At the same time, expanding, the polyurethane foam tightly fills the entire space, clogs up all the potholes and cavities, creating an airtight layer.

Such material reliably insures the surface against the presence of cold bridges causing condensation to form. The entire treated area will be dry, which will protect the roofing material and rafters from corrosion and decay.

After complete spraying of polyurethane foam and its hardening, only sheathe the entire treated area with sheet materials - plywood, chipboard or the like, and make a cosmetic decoration of the room.

Semi-professional polyurethane foam spraying kit

PPU should be sprayed between the rafters, carefully filling up all the cracks and voids

Self-spraying PPU

Advantages and disadvantages of polyurethane foam

The advantages of PPU are:

Incombustibility.
No reaction to water vapor, splashes, practically does not absorb water.
Excellent adhesion to any materials. (exceptions - polyethylene and fluoroplastic, wet surfaces).
Excellent thermal conductivity, low reaction to temperature changes, no temperature changes in properties.
Elastic structure, excluding the appearance of cracks during shrinkage and other deformations of the substrate.
Complete cut-off of the treated surface during application.
Lack of insects, rodents, birds.
Does not rot, does not react with contacting elements.
Durable, manufacturers declare service life of 30 years, but in practice, the PPU works longer.

However, there are also disadvantages. These include:

High price.
High manufacturability of application, the need to use special equipment.
The applied layer must exceed 5 cm, less thickness will not provide effective work.

Carefully!

It is afraid of ultraviolet radiation, which does not allow its use in the open form. The rate of destruction of polyurethane foam from sunlight is about 1 mm per year. At the same time, complete destruction does not happen, the process does not go deep into the material. The problem is eliminated by painting or decorative PPU fencing from direct sunlight.

All the advantages of the material have been repeatedly tested and confirmed in practice, and the disadvantages are quite easy to eliminate. The high cost of PPU as a material is compensated by it self-sufficiency, which allows you to significantly save on the purchase of a double layer of waterproof membrane.

Incombustibility is achieved by adding halogens to the original components, which makes it possible to classify polyurethane foam as a fast-extinguishing material. If there is no open fire, PPU cannot ignite in any way, therefore, it can be considered completely safe in this respect.

As a result, we can conclude that roof insulation with polyurethane is not only efficiently, but also profitable.

A really indisputable fact is the need to use a spraying device, although it is difficult to say if this is a drawback, or just a feature of the application.

In the event that you are planning, be sure to check out the article at the link.

If you attract specialists who will work with professional installations, then there is no need to purchase disposable kits. At the same time, the quality of the coating will be maximum and mistakes caused by lack of experience can also be avoided.

Useful video

Conclusion

Polyurethane foam is the most effective and high-quality insulation, leading in all respects among other materials. The use of such a coating is the best choice for the roof of a private house, reliably protecting the attic from cold and noise, guaranteeing a long-term service and not losing its properties over time. Any alternative is inferior in quality, confirming the leading position of PPU as a heater.

In contact with

One of the most effective ways to combat drafts and frozen corners is sprayed polyurethane foam PPU for house insulation. Due to its positive characteristics, this lightweight and easy-to-use material has excellent thermal insulation properties.

Polyurethane foam polyurethane foam - properties and characteristics

Liquid polyurethane foam is the result of a combination of two liquid components, which are polyol and isocyanate. Mixing the components allows you to get a fluffy mass sprayed onto the insulated base.

Liquid Polyurethane Foam Specifications

Density - 18-300 kg / m 3;
Thermal conductivity - 0.019-0.03 W / m ∙ K;
Water absorption - 1.2-2.1%;
Compression resistance - 0.15-1.0 MPa;
Bending resistance - 0.35-1.9 MPa;
Closure of pores - 80-95%;
Flammability class - hardly combustible (GOST - 12.1.044);
Service life - 25-35 years.

Depending on the structure, PPU is divided into two types:

Semi-rigid polyurethane (has an open cellular structure);
Rigid polyurethane (closed).

Spraying polyurethane foam is mainly used to insulate apartments in multi-storey buildings. Thermal insulation is performed where areas of the room are most susceptible to noise and cold air flow from the street.

Most often these are corner apartments, places near balconies, inter-apartment walls. It is possible to insulate the kitchen and bathroom with polyurethane foam.

Rigid PU foam

Good insulation, but with low vapor permeability. Sufficiently dense and durable in consistency. High cost compared to semi-rigid.

Semi-rigid polyurethane foam

Has a high level of moisture absorption and vapor permeability. They insulate walls, ceilings, and a roof. If the insulation is external, a high-quality finish, protected from moisture, is required. Used for wooden buildings.

Ideal for complex surfaces, does not weigh them down and easily penetrates any crevices.

Sheet solid

In addition to the liquid form, there is sheet polyurethane foam, also called solid. It is produced in various densities and thicknesses.

Fastening is carried out on a pre-leveled and cleaned plane by means of adhesives. Between themselves, for greater tightness and solidity, the sheets are glued using polyurethane foam.