Is it possible to insulate foam walls from the inside and in what situations it is better not to do this

Gusevsky Andrey Anatolyevich

In the photo we see the process of warming the internal walls of the house with foam sheets

Polyfoam is a material that has appeared on the construction market for a very long time, but traditionally causing a lot of controversy and disagreement. Some say that it is convenient and inexpensive, others say that it is dangerous and not of high quality.

Who is right? We will try to answer this question in this article, and also we will figure out whether it is possible to insulate the walls from the inside with polystyrene foam. After all, it is with internal insulation that the maximum requirements are imposed on materials.

Polyfoam: characteristics and common misconceptions

Polyfoam material is very light and quite inexpensive, but it holds heat and sound insulation well

The answer to the question of whether it is possible to insulate the walls with foam from the inside, is unequivocal - yes, it is possible. But many people continue to argue that doing this is undesirable. Around this material there are a lot of legends and myths, many of which were generated in the last century, when polystyrene was rarely used as a heater, and served only as a protection of goods during their transportation.

Today, production technologies have undergone many changes, and from the polystyrene that was previously left only a name. However, many continue to think in stereotypes. Let's look at the most common misconceptions regarding this material.

Stereotypes and Myths

Polyfoam very often insulate the walls of balconies and loggias

So:

• Styrofoam is highly flammable and may cause a fire., and also, it independently supports burning. So it was before. Indeed, the old foam easily flared up at the slightest contact with fire, but today flame retardants are added to its composition, which at high temperature break down the insulation into water and carbon dioxide, due to which the foam not only does not contribute to the spread of fire, but also prevents it.
• Styrofoam loses shape at high temperatures. Nothing like this. Modern polystyrene foam has a temperature range from -40 to + 80 degrees, that is, it can be used as a heater in any climatic zone, from the far north to the far south.
• Rodents start in the foam. This problem was relevant 20 years ago. The manufacturers also knew about it, which now add a special substance to the composition that repels mice and rats.
• Polyfoam has a persistent chemical odor that cannot be removed.. This is also a relic of the past. Previously, ammonia was used in the production of foam, which, after evaporation, formed granules. It was he who left behind an unpleasant amber. Today, ammonia is included in the list of substances hazardous to health, and is banned from production. He was replaced by freon, which after evaporation leaves no trace.

Styrofoam can be glued to concrete or brick walls using a cementitious compound.

Important! foam wall insulation from the inside has no restrictions, but only if it contains the PSB-S marking in the name, where the last letter indicates the presence of flame retardants in the composition. Polyfoam without flame retardants is cheaper, but you can not use it as a heater for walls for safety reasons.

As you can see, there are a lot of errors, and all of them are not true.Of course, this material is not perfect, and has a lot of disadvantages, and we will definitely talk about them a little lower, but for now, let's look at its advantages, which make foam so popular and sold material.

Do you still have any doubts about the foam? Then we suggest you watch the video in this article, which shows the production process. After viewing, you will be convinced that this material is completely safe.

Benefits

Polyfoam is not susceptible to mold and fungus infection, so it can be used in wet rooms.

So:

• Relatively low price. In the market of insulation materials, polystyrene is one of the cheapest. When considering its heat capacity.
• A light weight. Polyfoam does not create a load on the walls, so it can be used on light partitions.
• High degree of heat capacity. Polyfoam can even be used to insulate walls on the loggia (seeFinishing and insulation of balconies and loggias in the home), and with proper installation, it completely eliminates the cold bridges.
• Waterproofing. Styrene heaters are not able to absorb moisture, and they are not afraid of even prolonged contact with water, not to mention condensate.

The foam can be of different thicknesses, which is convenient for small, by volume, rooms

• Resistant to mold. Since polystyrene is a product of the chemical industry, spores of fungus and mold cannot develop on its surface.
• Durability. Given all the above characteristics, we can conclude that the walls insulated with polystyrene foam will last a dozen years.
• Easy installation. Below you will find detailed instructions for working with this material, but for now, we note that it is very easy to mount it with your own hands, and that is important quickly.

Given the above set of positive qualities, polystyrene could be called an ideal material, if not for a set of shortcomings, which simply need to be mentioned to preserve an unbiased look.

disadvantages

Polyfoam easily crumbles, this must be remembered when installing it both on the walls and on the ceiling

It:

• Lack of vapor permeability. Mold cannot grow on the foam, but it can find its place on the wall itself. And all due to the fact that the foam will not allow moisture to evaporate from beneath its surface.
• The need for additional insulation of joints. Polyfoam is made in the form of simple sheets, without grooves and ridges, therefore, in order to exclude cold bridges, the joints between the plates will have to be processed additionally.
• Plate thickness. Due to the porous structure, the thickness of the foam plate is rarely less than 5-10 centimeters, which means that you can insulate the walls with foam from the inside, but only if you are willing to sacrifice 30-50 centimeters of room space.

Since the foam does not allow air to pass through, it is not recommended to insulate the walls with it in residential premises

As you can see, the disadvantages of the foam are much less than the advantages, and in fairness we will give a small table in which we will try to compare the foam with mineral insulation by the main technical characteristics:

Advice! Before insulating the walls with polystyrene foam from the inside, make sure they are protected against mold. If condensate is present on the surface, then it must be treated with special impregnation with an antiseptic in the composition.

Polyfoam Installation

For the installation of foam on the walls for their insulation, do not require special skills or expensive equipment

Drawing a conclusion from all of the above, the question of whether it is possible to insulate the walls from the inside with foam is considered closed. Yes you can. And it remains only to determine the installation method. There are two of them and the choice completely depends on the characteristic features of the walls, but first things first.

Method one: on the dowel

We see an example of fixing foam with dowels with plastic caps, in order to avoid its destruction

For fastening insulation materials, there are special plastic dowels with a wide hat. When clogged into a wall, their lower part expands in a pre-drilled hole, and the plate is firmly pressed to the base. Thanks to the wide head, such dowels can be used to fasten not only polystyrene, but also soft heaters, such as mineral wool.

The fastening process is very simple, and in order not to focus on it, we suggest you watch how the walls are insulated with foam with your own hands in the video. The video shows how quickly the installation is done, and that this does not require any special knowledge and experience.

By the way, if the walls of your house are built of wood, then this is the only way to fix it, and before how to insulate wooden walls from the inside they must be thoroughly soaked with foam plastic with special impregnation, which will extend the life of the tree and prevent it from decaying due to condensation.

Method two: on glue

We see the process of applying glue to a foam sheet, for its further installation on the wall

This method is even simpler than the first. It is ideal if it is necessary to insulate brick walls from the inside with foam. The glue is applied to the plate and it is pressed to the base.

The setting time is about five minutes, so you have to keep the sheet pressed for a while. This affects the installation time, but on the other hand, you do not need any tools at all, except for a trowel or construction spatula.

By the way, the same glue that is used for installation is also suitable for insulating joints. After all the plates are fixed, the joints are rubbed with glue and allowed to dry. Then you can make the final finish.

And in conclusion

Today, foam is the simplest and cheapest material for wall insulation.

Few material is surrounded by so many stereotypes and myths as polystyrene. But do not believe the rumors. Much more weighty evidence of the quality and safety of this material is the permits and tolerances from the controlling authorities for the use of polystyrene as a heater for the repair of children's and public institutions.

So, we hope that we were able to answer all your questions and dispel doubts, and the video wall insulation with foam from the inside helped to understand the simplicity of attaching this material to the wall. If you still have any doubts, then on our site you will find a lot of interesting things regarding working with polystyrene foam and its qualitative characteristics.