Pros and cons of polystyrene foam as insulation for a wooden house

Insulating a wooden house from the outside with polystyrene foam is a very common occurrence. This thermal insulation material has both many advantages and some disadvantages that limit its use as insulation. Among professional builders, debates about the possibility of using polystyrene foam in a wooden house continue. Due to the high flammability of this material, many experts do not recommend using it for thermal insulation of wooden structures. In this article we will take a detailed look at the characteristics of the material and try to figure out how safe it is to use it as insulation. You will also learn how to properly cover a wooden house with foam plastic.

What is this building material?

First, let's figure out what polystyrene foam is? Knowledgeable people sometimes call it expanded polystyrene. This material, which is often used in construction for insulating houses, is a plastic mass.

These masses are usually filled with gas or air. The most common type is foamed polystyrene. The dimensions of the foam do not exceed 15 millimeters. Polystyrene foam contains 2% polymer, the rest of the space is filled with air.

The material is made from polymer under high pressure and using a gas generator, due to which it has a high density. High sound and thermal insulation are the distinctive features of this material, which is why it is so popular in construction.

Expanded polystyrene insulation

Any type of material is subject to environmental influences. Products are affected by temperature fluctuations, humidity changes, sunlight, precipitation and other natural factors. Therefore, to prevent the gradual deterioration of the foam, insulation is used to protect vulnerable areas. In the case of a wooden house, the fight against humidity, which provokes putrefactive processes, is especially important.

Arrangement of the frame on the building Source ultra-term.ru

The advantages of this insulation

What are the main advantages of insulation with this particular material? Several points can be highlighted here.

The first is, as mentioned above, high thermal insulation. Polystyrene foam is made using gas, which allows it to maintain the optimal temperature in the house.

The second is environmental friendliness. The material does not contain toxic substances, but only if the manufacturer did not use heat treatment during production.

The next advantage is high moisture resistance. This material does not retain moisture or accumulate it, that is, when insulating, dampness or the possibility of mold appearing is completely eliminated.

The fourth advantage is ease. The lightness of foam plastic greatly simplifies the insulation process, since the material can be easily cut or sawn.

And the last thing I would like to note is accessibility. The cost of this material is not high, absolutely anyone can afford it.

Video description

What is the best way to glue polystyrene?
Before directly applying the glue, the surface must be treated with antifungal and antiseptic drugs. It is important to choose the right composition, since subsequently access to the junction of materials will be very difficult.

The cheapest option is dry polystyrene foam adhesive, which is made from cement. For use, this product is diluted with liquid. The result is a reliable and durable compound for attaching foam to virtually any type of material.

Also recently, solutions based on polymer cement have become increasingly widespread. They are universal in use and are well suited for gluing insulation to any type of base. To work with facades, you can use products that contain various mineral fillers. Many companies produce products to increase the protective properties of polystyrene foam. After applying glue to the front surface, the material becomes resistant to various environmental factors. In addition to the advantages, such substances also have disadvantages - a long polymerization time, which is about 3 days.

There are also aerosol mixtures containing polyurethane. They can be used as glue or to fill gaps and seams between sheets. These are universal substances that behave equally well both indoors and outdoors. They can be applied to facades, roofs and walls of houses, flooring and other wooden surfaces. In all these cases, the products set quickly and hold the material securely for a long time. And although the prices for such mixtures are relatively high, they are justified by the convenience of applying the glue.

Expanded polystyrene sheets usually begin to fix within 2 hours after gluing the surface. For better stability, the material is secured with anchor bolts for facades.

The main advantages of polyurethane products are: fire resistance, good tolerance to changes in humidity and temperature, environmental friendliness and safety for health. Modern production technologies make it possible to obtain high-quality and easy-to-use compositions. When choosing an adhesive, it is important to consider its chemical reactions with the material. To prevent the destruction of polystyrene foam, you need to purchase products that do not contain acetone or gasoline.

Sometimes sheets of expanded polystyrene need to be glued together. For these purposes, use any wet or dry glue that does not contain solvents. When choosing products, a specific task is taken into account, and then the most suitable product is selected to solve it.

Designation of foam plastic and types existing on the market

Many beginners come across different letters when comparing this material and do not know what they mean. These letters are a type of foam. Usually, it is marked as “PS”, then other letters and numbers are added depending on the type. There are several types of foam on sale.

The first type is non-press, it is manufactured without pressure. The granules are dried and foamed, and the process is repeated several times. The output of this material is more voluminous, airy, and the cost is much cheaper than the others.

The next type is extruded. It is made using a forming hole and the material is passed through it. This foam is completely waterproof.

The third type of foam is pressed foam, it is made by pressing. The material turns out to be more dense, but this does not make its thermal insulation higher. Pressed foam is not popular, since the market price for it is higher than that of non-pressed foam, but at the same time it is almost no different.

The last type found on sale is autoclave. It is produced by one American company, there is no additional information about it.

Fixing polystyrene foam to a wooden ceiling

Before starting the main work, the ceiling must be carefully prepared, whitewash, dust and debris must be removed from it. You should also immediately place the electrical wiring, which will then be covered with plates.

The sheathing for insulation is made from wooden blocks. They are laid at such a distance from each other that the sheets of material are tightly located between them. Then the foam itself is mounted, and adhesives or fasteners are used to secure it. The cracks and recesses are filled with sealant. You can also use polyurethane foam for this purpose.

Next, a vapor barrier is placed on the frame. This is a film that will prevent moisture from entering the ceiling from inside the room. Lastly, the foam boards themselves are laid.

During preparatory work, the ceiling should not only be thoroughly cleaned, but also its surface should be disinfected using antiseptics. Then the entire area is covered with primer. If it is impossible to remove all the whitewash, it is recommended to completely treat the ceiling with special glue. The product is applied to the material with a dotted line. The sheets begin to be placed from the middle, moving them slightly. For greater reliability, it is advisable to add fasteners. Expanded polystyrene is also strengthened using a reinforcing mesh, which is subsequently puttied and processed.

Foam depending on density

When insulating a wooden house with polystyrene foam, it is important to choose it wisely. The material is also distinguished by density.

1. PSB-15 is the lowest density. It is used when strength is not required. This type of foam is used in insulating carriages, attics and attics.
2. The most popular type is PSB-12, it is found most often on the market. This material is universal and is used for insulating walls, floors and facades. A big advantage of this type is also its high sound insulation.
3. The third type is PSB-35. You can guess that this is high-density foam. This type is used for insulating foundations or, for example, underground structures.
4. The final look is PSB-50. This material has the highest density and is used, for example, in road construction or in industry.

German models Grohe

Groe's installation is popular and in demand. The system offered by the German manufacturer is presented in several models, so you can choose a Grohe installation complete with a toilet that complements the installed bidet. You can also consider a solution such as a wall-hung toilet with a bidet function, which allows you to solve the problem of functionality and save as much space as possible.

At first glance, the installation with a Grohe toilet seems like an intricate and difficult-to-install design, but in fact its installation does not pose any difficulties. In this case, combinations of a proprietary design and a toilet or bidet of another brand are allowed. The installation of a Grohe toilet is characterized by the following qualities:

• Versatility;
• High strength and long service life;
• Ensuring water conservation;
• The presence of a miniature inspection window on the tank;
• No noise during operation.

The only drawback that the Grohe toilet installation has is its high cost (depending on the model, the price exceeds 10 thousand rubles).

Recommendations for selecting polystyrene foam

Thickness is the main and most important criterion when choosing polystyrene foam, and here you cannot be guided by the rule that the thicker the insulation, the longer it will last. After all, if the material is thick, there is a possibility that the material inside will begin to bulge when the temperature changes.

Indeed, it is important to take into account the density of the material, as well as manufacturing standards (when purchasing, look carefully at the fault line, it must be correct), it is worth choosing well-known manufacturers.

Preparing walls for insulation

You can’t just go ahead and start attaching polystyrene foam to the walls. A special insulation technology was invented a long time ago; it is quite simple. For insulation with this material, a special construction adhesive is used.

It can be purchased in “build. materials." Just like tile adhesive, it is sold in powder form, which must be diluted with water. This glue provides excellent “adhesion” of the foam to the wall.

If the surface is perfectly flat, then you should apply the adhesive mass as thinly as possible. Thin application should be both on the foam and on the wall.

In order not to “accidentally” waste all the glue at the very beginning of work, you can run a comb over these layers. After this, lean the foam against the wall, press and hold until it “sticks” completely.

If the surface is not smooth, then the application principle is different. The glue should be applied to the surface in small sheets, as well as along the boundaries of the wall and the material. For optimal fixation, you also need to apply glue to the existing recesses.

The insulation is glued onto the wall in a strict order, like on a chessboard, and after installation it is secured with special mushrooms. Here you will need a hammer drill to make holes and install the mushrooms. They are also attached in several ways: along the edges and at the joints.

Preparatory work

Preparatory work is an important part of the building insulation process. It is especially important to carry them out correctly for a wooden house. Wood is the best building material, but without proper care it quickly turns to dust. To prepare your home for insulation you will need:

• brush;
• antiseptic;
• primer.

If the house has been in use for some time, then you will need to carefully inspect the surface of the walls from the outside before insulating it. In some places the wood may already be damaged. Problem areas need to be treated. This usually requires removing the top layer with a suitable tool. If there is paintwork that was applied not too long ago, then you can leave it. But it is important to be careful that the coating does not react with the foam, as its gradual destruction may occur. The best option would be to completely clean the outer surface of the wall using sanding machines and further process it and insulate it.

Wood must be coated with substances that increase its resistance to fire. They are called fire retardants. After this, treatment is carried out with an antiseptic composition. This is done so that pests that can destroy the walls from the inside do not grow inside the structure. If there are metal elements on the wall, then it is advisable to cover them with bitumen mastic, it will prevent the occurrence of corrosion. Next, the surface of the walls of the wooden house is covered with a primer. In addition to the antiseptic, it will strengthen the top layer and improve adhesion with the adhesive.

Advice! If a plank is found that is affected by shashel, then it is necessary to replace it with a new one.

For a house made of solid timber, it is necessary to make an additional check of how the elements fit together one to one. If there are gaps between the beams, then it is better to caulk using hemp, moss or tow. This is a labor-intensive process, but it will improve the insulation of the entire house.

Frameless and frame methods of insulation

There are several methods of insulation - frameless and frame. What is their difference? The first one differs in that when insulating, the foam is mounted close to the wall.

All surfaces are treated in a certain sequence so that the insulation adheres better. The frame method of insulation differs in that processing is required only where the guide bars will be installed.

Technological difference between internal and external wall decoration

Most often, interior wall finishing is done using wet technology, that is, using glue. To save space inside the house, you should not use an additional frame or anything else. The stages of work are as follows:

1. Surface preparation and adhesive application.
2. Installation of foam plastic boards and blowing out the joints between them.
3. Applying the base layer of plaster.
4. Applying the final layer of plaster.

Exterior finishing is also done using wet technology in most cases. There is almost no difference between them. External installation differs only in some details and the number of work processes. An insulating film is used here, since external factors act on the foam from the outside. Stages of work:

1. Cleaning the base and priming it.
2. Installation of the base profile.
3. Layout of insulation placement and “fitting” on glue.
4. Eliminate gaps with foam and fix them with dowels.
5. Attaching the waterproofing film.
6. Applying the first layer of plaster.
7. Reapplying a layer of plaster.
8. Final application of the third layer of plaster.
9. Decorative finishing upon request.

When to insulate

It is optimal that the insulation of a wooden house from the outside is carried out in the summer, so that the yard is dry and warm. If it's hot outside, even better. Thus, there is no doubt that the walls will be sufficiently dry. When the walls are thoroughly dry, moisture will not enter as steam during further operation of the house.

There are many videos on how to properly organize the process. Any thematic forum will help. The technology is easy to understand on your own. When preparing the walls, they are cleaned of dirt and old paint. It is necessary to analyze whether the seal between the logs is in good condition. If not, such places should be filled with polyurethane foam.