3 ways to attach foam to walls and ceilings

Expanded polystyrene or foam materials are among the most popular insulation materials. Polystyrene foam is lightweight, retains heat very well, reliably protects against drafts and does not rot in a humid environment. At the same time, it is inexpensive and quite easy to install. The service life and quality of polystyrene foam thermal insulation mainly depend on the correct installation of the material. How and with what to attach foam to the wall correctly?

Foam sheets are fixed in three ways:

fastening (when fixing to concrete/brick bases) on dowels - nails with large “umbrella” heads or through washers (when laying on wood);
in expansion on polyurethane foam - when insulating frame structures;
adhesive – when working with various surfaces.

The choice of method depends on the type and characteristics of the object being insulated. The fastest, most versatile and convenient way to attach foam to the wall is with glue, but it also has its pros and cons.

Advantages:

the possibility of finishing bases on which the material cannot be fixed with dowels - umbrellas for thermal insulation or in spacers: these are metal and plastic solid surfaces, thin wood-composite boards that do not hold nails, etc.
the most dense, reliable and airtight fixation of sheets to the wall if the foam is glued correctly

Flaws:

the need to dilute the adhesive composition (with the same adhesive foam for polystyrene foam it is easier - “walk” along the joints and put the container aside);
higher cost (when expensive glue is used or the consumption of the adhesive solution is too high due to installation features);
if for some reason the polystyrene foam comes off, all the work will go down the drain (the foam shot with dowels “umbrellas” (or “fungi”) in the corners and in the center can only burst, but will never “fall off” from the base).

Features of the work on insulation with polystyrene foam from inside the house

Insulating walls with foam plastic from the inside of a house has its advantages and disadvantages.
The work on fastening to the wall is not affected by external weather factors; the area of the insulated surface is relatively small, which eliminates unwanted sliding of the sheets. As a disadvantage, one can note the reduction in the internal volume of the building. The additional thickness of the insulating structure further reduces the area of the rooms. For internal installation of insulation, the thickness of the foam sheets can be no more than 40 mm, and fastening can only be done with glue. The use of profiles for laying foam plastic and additional fastening with dowels can be abandoned.

It is quite possible to do this work yourself. How to attach polystyrene foam to the wall. There are two ways to attach foam to the wall - using glue and mechanical fastening with dowels “fungi”. Mechanical fastening is usually used as additional fixation of glued foam. To fasten using this method, it is necessary to profile the wall with thin wooden blocks or special profiles.

They are aligned in a plane; this determines how evenly the polystyrene sheets can be strengthened. Holes are drilled in the profile according to the diameter of the dowels used, usually 8 mm. Using dowels and these holes, the material is attached to the bars. We will not consider fastening with drilling directly into the wall as extremely inconvenient.

The use of expanded polystyrene in the construction and reconstruction of buildings

External wall insulation with polystyrene foam has received the most widespread use in the use of this material. The thickness of the sheets in this case is from 50 mm to 100 mm.

Before starting this work, wall preparation is important. The foam is attached to the walls using special glue and plastic mushroom-shaped dowels. According to the work technology, reinforcement with dowels is carried out only three days after gluing.

For corners use a special corner profile.

All this prevents the material from slipping while the glue dries during work. After all, the amount of slipping of even a light sheet can reach 10 cm. After gluing the foam sheets, a reinforcing mesh is used to create a more rigid layer under the plaster. This will make it easier in the future to finish the building’s exterior, plastering and painting. External thermal insulation work can only be carried out on days without rain.

Application of mastic under the mesh, leveling mastic, or primer should be done only after the previous layer has dried. The air temperature must be at least 5 C°. High environmental characteristics and fire safety made it possible to use this material for insulation from the inside of the house. Such work is carried out if external installation is impossible or inconvenient.

Methods for gluing foam boards

To increase the efficiency of thermal insulation, the plates must be glued together

At the same time, it is important to choose the right adhesive that does not contain components that damage the foam. These include:

alcohol-based solutions;
solvents containing acetone;
Oil and gas products.

The best options for gluing foam boards are:

"liquid Nails";
polyurethane glue;
PVA.

It is impossible to give an unambiguous answer to the question of what is the best way to attach polystyrene foam to a particular surface. This depends on a number of factors, including the conditions in which the insulation will be used. If any controversial issues arise while carrying out the work yourself, consult with specialists.

Special cases at work

For gluing to a metal base, use liquid nails

Fastening polystyrene foam to a concrete, brick, or wooden wall are the most common cases. In practice, there are situations when it is necessary to fasten sheets of material to a metal surface. Then the work is done as follows:

indoors and when high strength of the coating is not required, PVA glue is used: the intermediate material - burlap - is impregnated with it; after which it is fixed on the working surface; then slabs lubricated with the same adhesive are glued onto it; for exterior finishing it is better to use special polyurethane adhesives together with liquid nails (so that the attached slabs do not slide); you can attach the foam with polyurethane foam, applying it at 5 points on the sheet in a small amount.

The use of liquid nails separately does not provide this level of strength. Joint application will increase the speed of installation. To learn how to quickly glue polystyrene foam to walls, watch this video:

Insulation of balconies and loggias can be done without gluing sheets, spreading them out in the sheathing.

After installation, the entire surface is puttied according to the level. Sheathed either with plastic, or MDF, or gypsum board. From the outside, the foam is held, securely fixed, by the outer wall.

There are nuances when working. You can't provide for everyone. Knowledge of how to secure material and practical skills will allow you to cope with any obstacles.

To work in multi-storey buildings, professional high-altitude workers will be required

Insulating a house using polystyrene foam methods is easy to do yourself. They can be combined with each other.

The decision on how to attach depends on the operating conditions and financial capabilities. Only facade work may require the involvement of professional high-altitude workers. Well-attached sheets of foam plastic will allow you to insulate your home for decades while preserving the exterior finish.

09.10.2017

In order not to heat the air outside the house, owners try to install thermal insulation. For this, a wide variety of materials are used, ranging from mineral wool to polystyrene foam.

The most popular due to its technical characteristics and affordable price is polystyrene foam. To reduce the cost of work, the owners do all the work themselves. That’s why questions are often asked: how to attach polystyrene foam to the wall?

Fixing sheets using glue

All preparatory work boils down, as in the first case, to cleaning, priming, puttying and protecting the surface to be pasted.

From the materials we will need:

Styrofoam.
Special glue for foam plastic. It can be supplied in dry form, liquid form or in special cans.
Polyurethane foam.
Special fasteners (fungi and impact screws).

The list of tools must include:

Spatulas 100mm and 200mm.
Rule.
Scaffolding or stepladder.
Hacksaw and knife for cutting foam.
A drill or hammer drill for drilling holes in the ceiling.
Screwdriver for screwing screws.
Hammer.
Measuring tool, level and twine.

Algorithm for performing the work:

We analyze the unevenness and horizontal level of the ceiling.
We nail and install the necessary beacons and cords.
Apply the adhesive to a sheet of foam plastic or to the ceiling. When applying glue to the ceiling, you can correct all surface irregularities due to a thicker layer.
Glue the sheet to the ceiling. All sheets must be glued in a checkerboard pattern to form T-shaped joints. We control the level and straightness according to the rule and beacons.
After gluing the material to the ceiling, wait 3 days until the adhesive mixture dries completely and shrinks. It is not recommended to fasten the sheets with fungi until the mixture has completely dried.
We nail the insulation with special fungi. This fastener has a leg, a plastic head and a special nail (metal or plastic). The latter is driven into the sleeve and secures the fungus in the hole. To do this, drill holes with a diameter of 10 mm using a hammer drill or hammer drill. The estimated depth of the hole should be equal to the length of the fungus plus 2 cm. The length of the fungus is selected so that it is 6-7 cm greater than the thickness of the insulation.
We place the holes for the fungi so that the fasteners are located in the butt joint of the corners and in the center of the sheet.
First, we hammer the fungi with a hammer without nails; the cap should be located in the same plane as the insulation.
Then we begin to hammer and fasten the nails inside the fungi. High-quality fasteners are recessed 1-2 mm into the body of the foam.

Preparatory work

Before attaching the foam, you need to prepare the surface.

There should be nothing on the wall that could interfere with the work. All structures must be removed. Clean the surface from dust.

If there are cracks, chips, unevenness or other damage on the wall, then they must be eliminated before attaching the insulation. Irregularities on the wall of more than 1 cm can cause insulation failure. If the walls are damp, they need to be dried.

The next important step in preparation is treating surfaces with special compounds that will prevent the formation of mold and mildew. The next stage of work can be started only after they have completely dried.

Scheme of insulating walls from the outside with polystyrene foam.

After the preparation is completed, you can begin drawing up a diagram of the location of the foam sheets on the wall.

Such a scheme will help to minimize losses from cutting sheets. On the wall they should be arranged in a checkerboard pattern. If the foam needs to be cut, then it is better to use a mounting knife.

The foam can be attached in several ways: with glue or mechanical fasteners.

To fasten foam plastic to the wall, use special dowels, which are also called umbrellas or mushrooms. You can use any of these methods, but, as practice shows, it is most rational to simultaneously glue and nail the foam. During facade work, this technology is most justified, especially if heavy facing materials will be used later.

It is better to fasten the insulation only with glue during interior work; this will be quite enough. Dowels do not need to be used as fastenings for foam plastic, since heavy facing materials are not used during interior work

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The easiest way to attach foam to the wall is to use glue. Work begins from the bottom with the installation of a starting bar.

The plank will become a reliable support for the bottom row and will not allow it to move. This method will allow you to do the job correctly and with better quality. If you do not use the limiting strip, then until the adhesive mixture dries, the foam can drop up to 10 cm.

Scheme of external insulation from foam blocks.

The thickness of the starting strip should be equal to the thickness of the insulation sheet. In addition to the strip, to attach the insulation, you will need:

Tile adhesive. Construction mixer. Electric drill. Large and small spatulas. Container for glue.

When preparing the adhesive mixture, you must strictly adhere to the instructions. Using a construction mixer attached to an electric drill, prepare the solution, strictly observing the proportions of water and dry mixture.

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Two spatulas are needed to make it more convenient to work. The small one is used as a spatula to spread the mixture onto the large one.

On a perfectly flat wall, you can work with a spatula-comb with special teeth. If the surface has differences of more than 1 cm, then the mixture is applied to it with a spatula in separate “islands”. Due to this, all differences are leveled out as much as possible, that is, a larger amount of glue is placed on the unevenness, and less on the protrusions.

Graph of thermal insulation properties of insulation materials.

The adhesive mixture can also be placed on foam plastic. Manufacturers recommend applying it evenly over the entire surface.

But here you may encounter the following problem: if the wall is uneven, then half of the sheet may not stick. In addition, the sheet will become 3-5 kg heavier and will be inconvenient to work with: hold, fasten, level. Therefore, for convenience and reliability, it is better to apply glue to the wall.

The adhesive mixture is applied in “islands” along the perimeter of the foam sheet. "Islands" can be of various sizes. The main task is to level the insulated surface as much as possible if there are depressions on it.

All existing protrusions should be knocked down, if possible. Alternatively, you can scrape off the insulation sheet a little in the place where the protrusion hits. In addition, the glue must be applied to the wall along the perimeter of the sheet in a broken thick line.

For this it is better to use a small spatula. This technique will allow some of the glue to get under the adjacent sheets. Thanks to this, the joints will be more durable.

Attach the sheet to the prepared surface and press lightly. To avoid making dents, fasten carefully. The sheets are stacked in a checkerboard pattern.

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One of the types of fastenings for foam plastic are special dowels - mushrooms, which consist of a plastic circle (hat and plastic sleeve) and a “leg”. A plastic or metal nail is driven into the sleeve. It is better to fasten with plastic nails.

For work, in addition to the dowels themselves, you will need:

Perforator.Drill.Hammer.

The depth of the hole for fastening should be 20 mm greater than the length of the fungus. To decide how long to prepare the fungi, you need to add 1 cm to the thickness of the insulation as the thickness of the other layers on the wall and add another 3-4 cm to the recess.

For example, with a foam thickness of 50 mm, you will need mushrooms with a length of 50 + 10 + 40 = 100 mm. In this case, the depth of the hole will be 100+20=120 mm. You need to prepare a drill for the hammer drill of the same length.

Fasten the sheet with at least 5-6 dowels, placing one in the center, the rest at the joints of the sheets.

Thanks to this, the joints are better pressed. If necessary, you can attach more material. Dowels are considered the best and most reliable among foam fasteners.

First prepare the holes for the fasteners. Then insert the fungi into them, without nails for now.

Hammer it with a hammer so that the cap is level with the surface of the insulation. When all the fungi are installed, you can start driving nails inside. A correctly hammered mushroom is immersed in the insulation by 1-2 mm.

It is very important to take into account that the insulation can be nailed no earlier than 3 days after gluing is completed. During this time, the adhesive mixture will dry and the foam will not move away from the wall.

To insulate buildings during modern renovations, materials derived from polystyrene foam are often used: polystyrene foam, penoplex. Their composition is more than 90% air. This determines their high thermal insulation properties.

Before attaching polystyrene foam to the wall outside or inside the premises, you should prepare the working surfaces and decide on the installation method. Not only the service life of this material, but also the durability of the decorative finish will depend on the quality of fastening of the sheets.

How to attach foil polyethylene foam

Reliable and high-quality installation will ensure the proper functioning and durability of the thermal insulation. To install insulation, special adhesives are most often used. Penofol is a fairly lightweight material that is easy to attach to almost any surface. For installation, you can use universal or special glue, which must withstand temperature changes. Some craftsmen allow fastening with liquid nails or polyurethane foam. In some cases, the rolled material can be additionally secured with construction staples. Class C penofol is produced on a self-adhesive base with waterproof glue. This type usually does not require additional installation tools.

Remember that the condition and preparation of the base for insulation is one of the most important factors for reliable fastening. So, the surface should be leveled as much as possible, get rid of bumps and irregularities, thoroughly clean and degrease. Make sure that the inside of the insulation is not dirty. It is recommended to additionally prime concrete, wooden and metal bases before installing penofol. Penofol layers are attached strictly end-to-end, and it is advisable to cover the assembly seams with aluminum adhesive tape.

Calculation of the required amount of materials

Any work related to repair and construction begins with the calculation of the required amount of material. To do this, it is enough to know the area of the surface to be covered. To insulate residential premises, foam plastic of various thicknesses is used, but the ideal material would be one whose thickness is more than 5 cm, and its density ranges from PSBS-15 to PSBS-35.

To fix the boards, you can use dowels, foam glue or regular cement-based glue. When choosing an adhesive, consider the following points:

there should be a mark on the package that the adhesive is suitable for fastening polystyrene foam boards;
the purpose of the glue can be installation of insulation and filling cracks or with the possibility of installing a protective layer.

Calculation of glue should be carried out taking into account the evenness of the surface. The average amount required to install insulation with your own hands is about 5 g/m2. Approximately the same amount will be required for attaching the reinforcing mesh and leveling layer.

There are general rules for preparing the solution:

The thickness of the adhesive should be such that the solution does not change its shape when applied. That's why sometimes you should deviate a little from the manufacturer's recommendations;
to attach the reinforcing mesh, the glue should be a little thinner. This is required for better deepening;
The solution should be even more liquid when using it at the final stage, for installing the leveling layer.

CONSTRUCTION FASTENERS

When using fungi to securely fix the insulation, it is necessary to calculate the amount of material per square meter. During the calculation, they are guided by building codes. To secure penoplex to wall surfaces, 4 fungi are used, which are located in the corner part of the material. In some cases, one element is added in the central part of the insulating sheet. At the corners of the room, about 6 fasteners are used to secure the insulation per square meter.

If the height of the facade is from 8 to 20 meters, then 7 pieces of dowels are required per square meter. In a multi-storey building, 9 pieces of fungi are consumed per square meter.

Using dowels

Fastening polystyrene foam using dowels. A simple, inexpensive, quick and durable glueless method of fastening polystyrene foam, however, requiring the use of a hammer drill and the required number of umbrella dowels. Their length is selected sufficient for reliable fastening of the slabs to the concrete base (taking into account the thickness of the sheets). On a clean, flat surface, a lower starting level is set, from which installation begins.

Each sheet is fastened with three dowels: one in the middle and two in the corners, so that their “umbrellas” press the corners of adjacent slabs. A gap of 3 mm is formed between the sheets - a deformation-temperature seam, which eliminates mutual deformation of the plates during daily and seasonal changes in temperature and humidity. Sealant is applied to the seams.

Additional Tips

The fungi are placed at the joints of the sheets, this will help to avoid the presence of additional holes in the insulation. That is, with such work, the thermal insulation properties are preserved and cold bridges are not formed.

When installing a dowel into a metal coating, a self-tapping screw is attached to the rod of the fungus. Using a self-tapping element, the fastener is immersed in the heat-insulating material so that it reaches the main surface. Then the dowel is screwed into the metal surface with a screwdriver, the depth of the hole for the screw is made about 15 millimeters. When the installation of the thermal insulation material is completed and the sheets are properly secured, all connections are closed with aluminum tape.

With the right choice and counting the number of dowels, the penoplex will be securely fixed. Before you start fixing sheets with dowels, you need to calculate the number and required length of fasteners.

Using polyurethane foam

Here's how to glue foam to concrete quickly and firmly!

The consistency contains polyurethane, which has several advantages:

Fastening the products occurs without any particular difficulties.
The adhesion of polystyrene foam and concrete is carried out as efficiently as possible.
The cost is low;
You can process seams between the joints of materials.
It is allowed not to even prime the surface.

The foam is applied to the slabs in a checkerboard pattern, after a few seconds you can glue the sheet to the concrete. There is no need to take breaks so that the foam does not dry out. The temperature when performing gluing work should be no lower than 20 degrees Celsius, the higher the better.

Excess foam should be removed immediately with a special cleaner.

Fig. 3 Technology of fastening foam with dowels

There are several ways to glue foam:

Glue them to the surface and secure them with dowels.
You can first place the foam on glue, and then strengthen it with special umbrella dowels.
Place in the sheathing
Glue directly onto the ceiling plane
Mechanical fastening using mushrooms, anchors and studs, etc.

Bonding polystyrene foam ceiling tiles to the ceiling

The tile ceiling is done in stages. First you need to measure the surface area of the ceiling and calculate, taking into account the adjustment, how many slabs you need to purchase. Before you start gluing foam, you need to stock up on the necessary materials and tools.

Use a drill and a special attachment for a construction mixer to stir the mixture and glue.
With a spatula-comb.
With a narrow spatula.
Use a wide metal spatula to level the surface.
Primer needed to prepare the surface to be repaired
Hammer with a 10 mm drill.
A plastic container for preparing the solution if a dry mixture will be used.
Wide primer brush.
Knife or other tool for cutting slabs
With a hammer.

Preparatory stage

First you need to buy all the necessary materials and tools that may be useful during the installation process:

Insulation.

The required quantity is calculated in advance and must be purchased with a reserve. During transportation and even during fastening, the slabs may be damaged, so a few sheets in stock will not harm. Starting profile. Adhesive composition suitable for external work. You also need to pay attention to whether it is suitable for fastening foam plastic. Fasteners (fungus dowel) if this method was chosen for fixation. Deep penetration primer. Roller or wide paint brush (for applying primer). Sealant. Perforator.

After all the equipment and materials have been purchased, you can begin preparing the foundation. To do this you need:

Remove old decorative trim.

If there are areas that are crumbling, then they are eliminated. All facade elements that interfere with the installation of insulation are removed. All cracks and recesses whose depth exceeds 5 mm are sealed. For polystyrene foam, it is not important that the base be perfectly level.

But if there are large depressions, then mechanical stress may cause cracks to appear both on the insulation itself and on the decorative finish. And this reduces the effectiveness of thermal insulation. Clean stains and traces of fungus or mold. The last stage of preparing the base will be the use of deep penetration soil. Particular care is taken in areas of constant exposure to moisture (basement, foundation).

Only after the soil has dried can you begin installing the foam using the chosen method. Now let's take a closer look at each method.

Foam panels on the ceiling: how to install it yourself

You can very easily make a ceiling in a room with your own hands, you just need to prepare the required materials and tools and put in a little effort.

Polystyrene foam is a very inexpensive but high-quality material that can be laid on absolutely any ceilings, in particular:

Plasterboard;
Wooden;
Concrete.

Polystyrene foam is a fairly versatile material that is suitable for both wooden and plasterboard ceilings

Finishing the ceiling with foam boards is carried out step by step. Before laying the tiles, it is necessary to first prepare the ceiling surface. It is imperative to free the ceiling from whitewashing, leveling and priming any existing defects. If there is fungus on the ceiling, then it must be thoroughly cleaned and then an antiseptic must be applied to it. You need to attach foam boards to the ceiling using special glue. Before gluing, you need to keep the tiles in a dry room for 3 days. You need to mark the ceiling from the center to the edges.

Initially, you need to cut the ceiling tiles into squares or rectangles of the required size, and then use special adhesives to fix them to the ceiling surface. Before performing finishing work, you need to disconnect the electrical wiring. After the surface of the ceiling is completely covered with slabs, you need to eliminate the gaps formed between the ceiling and the walls, using shaped molding for this. Such polystyrene foam moldings will add special style and sophistication to your interior design. Additionally, you need to use special corners, inserts for the chandelier, as well as devices for finishing the outlet. Everything should be in the same style.

A few important tips before starting installation

Regardless of which method you choose for installing foam plastic on concrete, remember that you absolutely always need to clean the insulated surface from unstable areas and dust particles, which in the future can reduce the adhesive properties of the surfaces

In addition, it is important to carry out high-quality work to remove deep cracks and strongly protruding irregularities, as well as carry out soil work over the entire area of the working surface in order to achieve the best results.

So, as you can see, today it is impossible to unambiguously decide on the choice of material for installing polystyrene foam insulation material on concrete, since there are a huge number of parameters that at any time can change the need to use any method. Remember that you need to choose an adhesive solution in accordance with the operating conditions, the characteristics of the wall, as well as your financial capabilities.

Adhesive foam fastening

This method is much cheaper than the frame method, since installation of sheathing is not required. You only need to have the required amount of foam and adhesive. You can even use an adhesive intended for working with tiles, which will significantly reduce the cost of insulating your home.

All actions must be carried out in the following sequence:

Placing foam on glue

Before fixing the foam to the ceiling, it is recommended to carefully prepare it. This requires cleaning the surface from dust and dirt, after which it is imperative to treat the ceiling with a disinfectant and primer. In the event that it is not possible to completely get rid of the lime coating, the entire surface of the ceiling must be coated with an adhesive solution and left for some time to dry completely.
Dilute the required amount of adhesive to a certain consistency.
Apply the solution to the foam board and press it to the ceiling. For a high-quality result, the solution should be applied correctly: along the edges in broken lines, and in the middle with slaps. The sheets must be glued starting from the middle of the ceiling in a checkerboard pattern. After fixing the solution, you need to give it time to dry.
After complete drying, the material needs to be further strengthened. Dowel nails are ideal for this. They need to be placed in the middle of the slab and in the corners. When driving the dowel directly, you need to ensure that the head is positioned flush with the edge of the material.
The next step is to remove any possible irregularities after installation. This is where a special corrective brush will come in handy.
A reinforcing mesh should be placed on top of the foam surface, after which it is recommended to putty the surface.

Regardless of the choice of method for attaching the foam. it is necessary to strictly follow the advice regarding temperature conditions (work can be carried out at temperatures from +5° to +30°), and also ensure that the sheets are laid as closely as possible to each other.

Preparatory activities

You can insulate a house with polystyrene foam in 2 ways: with glue or with special dowels

Insulation allows you to save on heating the room. You can attach the foam to the wall after preliminary preparation of the surface.

The process consists of performing a series of actions to level and strengthen the base. It all boils down to this:

unnecessary structural elements are dismantled from the working surface; falling sections of the finishing coating are removed to a solid base, after which they are plastered again; the walls are checked for unevenness with a level; if necessary, the entire surface is leveled and puttied; after drying, the dust formed on the installation surface should be washed off with water (you can wipe with a damp cloth); when the moisture has evaporated, apply sequentially: a primer layer, a solution against mold and fungi (with a brush or spray); before attaching polystyrene foam, you should take measurements of the wall (to order consumables in the required quantity, in a convenient format).

Preparatory operations also include the selection of tools. To carry out the work, depending on the chosen fastening method, you will need the following set:

spatulas of different sizes; construction knife, stapler; level, tape measure, pencil; hammer drill (impact drill); mixer or attachment for stirring the adhesive solution; sandpaper (grater); hammer; containers for glue, primer, plaster mixtures.

It is customary to pay great attention to preliminary preparation. Leveled walls without defects speed up further installation work, avoiding possible troubles (for example, panels falling off along with the plaster). It is recommended to use foam plastic 3 cm thick inside the rooms, and at least 5 cm thick outside.

Dowel mounting

Installing foam plastic on the wall using dowels will require the following tools:

hammer drill or drill;
pobedit drills;
dowels;
glue;
small spatula.

First, drill a hole in the foam using a hammer drill or, if you don’t have one, a drill. We place an umbrella in this hole and insert the dowel itself - a nail. You need to drive the nail inside using a hammer. After performing these manipulations over the entire surface of the slab, all umbrellas need to be plastered, after mixing a little glue.

Installation using dowels must be done so that the dowel passes through all layers of insulation and enters the wall to the required depth. For this reason, I would advise immediately calculating the required dowel length. The dowel should be closed with a special cap after driving in. This cap should not extend more than 1 cm into the foam. If the cap is set deeper, this may cause the foam to rupture.

In order to be sure of the required landing depth of the head, I recommend buying a cutter for your drill with a depth of 1 cm. This cutter will help you prepare special holes for the diameter of the head. After installing the dowels, these holes should be closed with plugs to prevent them from getting wet due to dampness or precipitation.

Dowels are also called mushrooms for attaching foam plastic or umbrellas. When choosing them, I advise you not to save money. Since cheap dowels can let you down and break right during installation. For one sheet of polystyrene foam you will need about four mushrooms or umbrellas. From this you can estimate the required volume, not forgetting about the reserve.

At the end of my article, I would like to give you a couple more tips. If this is your first time insulating walls, start with the wall that is least noticeable. In case of minor defects, you can correct them without fear of an unsightly appearance.

Try not to interrupt your work on one wall. Or try to finish work with wet materials. Cover the foam with a reinforcing layer in a timely manner, as it may turn yellow. I wish you good luck in such a rewarding task as wall insulation.

Mounting methods

Specialists use different methods to attach polystyrene foam.

Glue method.

This is a quick and convenient way to attach. It is enough to choose the right adhesive composition and then apply it to the insulation. Based on their initial state, adhesive compositions are divided into types:

dry mixes are bulk materials packaged in bags. They contain cement with binding additives. To prepare the glue, just dilute the solution according to the instructions;

liquid formulations are always ready for use. These include the adhesive composition “liquid nails” and cheap PVA glue. If PVA glues foam plastic well to metal surfaces, then “liquid nails” glue different materials, however, the glue is very expensive, so it is used on small surfaces;
foam - this type includes special adhesive compositions developed for foam plastic. First of all, these include:

Polyurethane adhesive that has good adhesion to foam. It is packaged in cans, so it is used with a special pistol.

Adhesive - foam provides reliable adhesion to various materials. A special gun makes it easier to use glue.

Fastening method.

Dowels with a wide head are intended to strengthen the fastening of slabs. They are used for external wall insulation, as well as when there is an increased load on the heat insulator.

There are several types of dowels, but they all necessarily have a sleeve, a core and a wide head. If the dowel is hollow, then a nail or screw is used in the spacer zone. The plate is fastened in the corners and in the center. Compared to gluing insulation, this method is more labor-intensive.

Combined method.

The simultaneous use of two methods of fastening the insulation allows you to achieve high quality installation. The adhesive composition isolates the surface from external influences, and the dowels increase the reliability of fastening.

Video instruction:

Methods for gluing ceiling tiles

So, we have determined where to start laying tiles, now we will look at what gluing methods exist. Everyone chooses the most convenient for themselves.

Snake

For this method, each subsequent row is laid around the previous one, as if entwining the central elements. The first fragments are glued in the center.

Crisscross

In this case, the panels begin to be laid crosswise. First, glue the first four squares in the center. Then straight lines are formed perpendicular to each of the walls. At the last stage, the resulting quarters are filled.

Rows from the corner

The first tile is placed in the far corner from the door. Next they move along the wall. After this, glue the next row parallel to the first. Work begins from the place that is best viewed upon entering the room. If you start working from the doors, you may find that in the most visible part of the room there will be an unsightly thin strip of scraps.

Advantages and disadvantages of polystyrene foam as insulation

Polystyrene foam is a more modern thermal insulation material, and also less finicky when compared with analogues. This allows you to significantly simplify the insulation process, which still depends on the type of roof of your house. In addition, it is distinguished by its fairly light weight and low thermal conductivity.

In addition, polystyrene foam is so popular because it has the following properties:

the low hygroscopicity of the material allows you to significantly save on the purchase and further installation of vapor barrier and waterproofing materials. However, in the case of finishing a wooden house, it is better not to neglect this;
this material does not shrink after installation, which is why so-called cold bridges may appear;
thermal insulation properties are maintained for a long time, about 10-20 years, provided that all installation rules are followed;
It is especially good for use in rooms with low ceilings, since a thickness of 5-6 cm is enough for complete insulation.

Despite all the advantages, this insulation also has some disadvantages that should be taken into account when choosing:

this material cannot be used in those rooms that are characterized by poor ventilation, since it has vapor barrier properties, thereby provoking the formation of condensation and a further increase in humidity. This can lead to the appearance of fungus, mold and a decrease in the effectiveness of the insulation. For people prone to allergies, this is unacceptable;
upon direct contact with an open flame, the material melts, releasing quite harmful substances in the process that can lead to paralysis of the respiratory tract.

When choosing a material, pay attention to the presence of quality certificates from the seller; this will protect you from purchasing low-quality goods, which may later cause harm to your health.

Conditions for insulating walls from the inside

There are certain conditions when it is possible to carry out internal thermal insulation and when it is not. If the insulation is not properly insulated, condensation appears on the walls, fungus develops under the insulation layer, and gradual destruction occurs. The formation of condensation indicates the location of the dew point, and its occurrence depends on the humidity and temperature in the house. The table will help you determine the dew point:

Dew point determination table

In addition, other factors are also important: the presence of a ventilation system, the quality of heating, the mode of operation of the home, the thickness of the load-bearing walls, and the region of residence.

Based on this, internal wall insulation can be performed under the following conditions:

people live in the house permanently;
the ventilation system fully meets established standards;
heating works without failures;
insulation is planned for all surfaces;
the walls always remain dry.

In all other cases, only external thermal insulation is allowed.

Prices for thermal insulation materials

Thermal insulation materials

Thermal calculation

How thick should foam plastic be for wall insulation? Simply sticking it thicker means not only wasting money, but also reducing the strength of the coating.

The initial value is the permissible value of specific heat loss in a given climatic zone, or the thermal resistance of a building R. For walls in the European part of the Russian Federation, the recommended values are:

South (Krasnodar – Astrakhan – Rostov-on-Don) – 2.8 kW/sq.m.
Black earth strip (Voronezh – Lipetsk – Volgograd) – 3.5 kW/sq.m.
Middle band - 4.2 kW/sq.m.
Boreal zone (Karelia – Arkhangelsk – Naryan-Mar) – 5 kW/sq.m.

In a specific locality and in regions with difficult weather conditions, R can be found from the appendices to SNiP, from the local department of architecture or the Municipal Internal Affairs Committee. For floor R is taken with a coefficient of 1.3; for the ceiling - 1.7. That is, in Moscow, the floor R should be at least 5.5 kW/sq.m, and the ceiling – from 7 kW/sq.m.

The indicated R values are obtained from typical values of the temperature gradient Γ from inside to outside. For example, in the Moscow region it is considered equal to 40 degrees: +20 inside and –20 outside. If Г changes by no more than 1.7 times, the dependence of R on it can be considered linear and taken with the appropriate correction. For example, you want to have +25 at home in Barvikha with -40 outside. G = 25 – (-40) = 65. 65/40 = 1.625. We multiply by it the recommended 4.2 kW/sq.m for the Moscow region, we get 6.8 kW/sq.m. This is the R value that insulation should be calculated at.

Next, you need to know the values of k for various building and finishing materials. What is this k? This is their specific thermal resistance, R of a square of material in a layer 1 m thick, i.e. Through a meter-thick square, at standard G, exactly that much heat will escape. Some meanings are:

Reinforced concrete grade 400 – 2.00 kW/m.
Cement-sand mortar grade 200 – 1.16 kW/m.
Silicate brick – 0.7 kW/m.
Fired ceramic brick – 0.56 kW/m.
The same, hollow – 0.35-0.41 kW/m.
Gypsum plaster – 0.43-0.47 kW/m.
Warm plaster (HS) on foam plastic or expanded vermiculite – 0.057 kW/m.
HS on perlite sand – 0.063 kW/m.
HS on expanded clay – 0.22-0.25 kW/m.
Expanded clay granules 20 mm – 0.16 kW/m.
Oak, laminate – 0.20 kW/m.
Pine, MDF, construction plywood – 0.16 kW/m.
Fiberboard, OSB, plasterboard – 0.15 kW/m.
Polystyrene foam PSB-20 – 0.033-0.035 kW/m.
The same, PSB-25 - 0.035-0.037 kW/m.
EPPS – 0.028-0.032 kW/m.

Next, we determine R of the available construct. Let's say this is a wall, counting from the inside out, of the following design:

Laminate 0.012 m (12 mm);
PSB-20 0.030 mm;
TS on expanded clay 0.020 mm;
A wall made of two clay bricks with a layer of 1 cm mortar - 0.50 m of brick and 0.010 m of mortar;
External cement plaster 0.030 m.

Rn of each layer is calculated using the formula:

Rn = pn/kn, where p – layer thickness in meters; n – serial number of the layer.

We have:

R1 = 0.012/0.20 = 0.06 kW/sq.m;
R2 = 0.030/0.035 = 0.85 kW/sq.m;
R3 = 0.020/0.25 = 0.08 kW/sq.m;
R4 = 0.50/0.56 = 0.89 kW/sq.m;
R5 = 0.010/1.16 = 0.008 kW/sq.m;
R6 = 0.030/1.16 = 0.026 kW/sq.m.

Total R = R1+R2+R3+R4+R5+R6 = 0.06+0.85+0.08+0.89+0.026+0.008 = 1.914 kW/sq.m. This is not enough even for Krasnodar, and already in the middle zone without insulation you will have to freeze, or pay an additional 4.2 - 1.914 = 2.286 kW (approx. 2.3) for heating for each square of the external wall area.

Now let’s calculate the thickness of the external insulation required to bring R to the standard of 4.2 kW/sq.m. We have already found out that we need to retain Rwarm = 2.3 kW/sq.m in the room additionally. We will insulate with EPPS, for which K=0.032 kW/; We take the upper value based on moisture absorption. The thickness P of the insulation is determined by the inverse formula:

P = K*Rwarm

We have: P = 0.032x2.3 = 0.0736 m. Sheathing made of 80 mm EPS or even PSB-25 will allow you to insulate properly, because there will also be plaster on the outside.

Foam plastic and expanded clay

The structure of polystyrene foam resembles foamed plastic material with a cellular structure. Most often it is found in the form of square sheets measuring 1mx1m. Its peculiarity is that it is used not only as an internal insulation, but also as an external one. The thickness of the foam varies from 20 to 100 cm. It is also used as a base for putty. When the ceiling is insulated from the inside with polystyrene foam, it can perfectly level the surface. This material has a number of other advantages:

universal;
has a low price;
durable;
reliable;
provides a good level of thermal insulation.

Fastening polystyrene foam is similar to installing penoplex.
Expanded clay is made from clay; in appearance it resembles balls. The principle of installing expanded clay on the ceiling is to pour it on the floor of the attic. Therefore, this method of insulation is applicable only for private houses. But at the same time it has the following advantages:

does not decompose;
fire resistant and fireproof;
eliminates the possibility of insects and rodents appearing in the material;
has good sound insulation;
waterproof and frost-resistant;
has good heat dissipation;
has an affordable price.

If you are planning to insulate your ceiling with expanded clay, pay attention to the following recommendations:

Before laying expanded clay, you should take care of the waterproofing layer on which the material will be poured.
The first thing to cover is the rafters and chimney.
To ensure high-quality thermal insulation, the expanded clay layer must be at least 16 cm.

Self-installation of polystyrene foam

As can be seen from the two descriptions, insulating walls using polystyrene foam yourself, both on a regular concrete and brick surface and on wooden beams, does not present many difficulties. The main condition for good masonry is step-by-step execution, high-quality materials used, strict adherence to recommendations and instructions, as well as desire and patience in the work. Any installation of such material will reliably protect the house from adverse conditions, protect the wood from rotting and deterioration, and also ensure good ventilation of the room and insulation.

This material is safe, non-toxic and will last for many years without repair or restoration. It has good thermal insulation, steam does not condense on it, and fungi and mold do not multiply. As an addition, you can treat the walls with a solution and disinfect the area before laying. This will help get rid of existing fungus and microorganisms on the surface of the wall. But this is done if necessary. There is no need to spend money and effort for prevention if the surface is normal.

Indoor mounting

Insulating indoors is a simple process, so it can be done on your own. To ensure high-quality fastening, work with foam plastic is carried out in a certain sequence.

The wall surface, insulation and adhesive composition are being prepared. The walls must be smooth and free of cracks and peeling. Polystyrene foam is easily cut with a hacksaw or a sharp knife. The adhesive used is a dry mixture or adhesive foam in cans.

The finishing of windows and doors is dismantled. Subsequently, higher quality finishing elements are installed.

The adhesive is applied along the edges of the slab, in the center and at the ends.

Fastening the slabs to the walls is done in one of the following ways:

in rows - the insulation is laid with a shift in rows along the entire perimeter of the room;

pyramid - the first row is laid around the perimeter of the room, and then the corners are laid in the form of a pyramid.

Using a spatula, remove the layer of glue squeezed out from the joints of the plates.

The surface of the insulation is covered with a mounting mesh, and plaster is produced.

Fastening to concrete and brick walls

Often, to insulate concrete and brick walls, a special sheathing is made that holds foam plastic slabs. Unfortunately, it is not always possible to install it, and in addition, additional costs arise. In practice, other fastening methods are in demand.

Using adhesive.

This method has its own peculiarities. Firstly, individual components of the adhesive can destroy the foam, and secondly, not every stickiness of the adhesive composition will bind the foam to concrete and brick.

The insulation boards are fastened in a certain sequence:

the surface is leveled, then dirt and oil deposits are removed from it;

The glue components are connected according to the instructions. The resulting composition should not contain water, then it will not come off for a long time;

the adhesive is placed on the slab in separate sections so that there is space for air to escape;

the insulation is pressed and held.

Using dowels.

Types of insulation

First you need to determine the type of insulation for the ceiling. which you can apply and it will suit you. The question is that there is a significant difference: the installation will be carried out from the inside of the room, or will be carried out from the outside. This will determine how to secure the insulation to the ceiling.

Mineral wool

This is perhaps the most common material used today. There are reasons for this. This insulation has many advantages over other materials:

This is a fireproof material that can also be used to insulate a bath;
Mineral wool has excellent sound insulation;
Tolerates temperature changes well;
Not subject to deformation;
Environmentally friendly material that does not harm human health.

Note: Please be aware of the following. All porous insulation materials, when compressed during installation, lose their properties.

Therefore, during installation they should be placed tightly, but not deformed.

Mineral basalt slabs

This is approximately glass wool, from which there are actually serious differences:

This material seriously resists fire and has increased fire safety;
The material is impregnated with a substance that repels water, which is why it has increased moisture protection;
Resistant to deformation. Here, a multidirectional arrangement of fibers is used, which increases resistance to deformation;
During the production process, materials are used that increase service life;
Can withstand almost any temperature;
This material can be used to insulate not only ceilings, but also foundations.

Liquid thermal insulation materials

Such elements appeared on the sales market relatively recently and have truly unique properties:

These are ceramic balls in huge quantities and have rather low thermal conductivity;
This miracle is prepared in the form of paint, which can be applied to any type of surface;
Excellent resistance to fire and moisture penetration;

This material is quite common and has many fans.

In principle, this is a universal insulation. Insulation can be carried out both from the outside and from the inside of the building. Can be applied to almost any part of the house;
It has a low price, which makes it quite attractive. Therefore, the cost of insulation will be affordable for anyone;
This is a material that lasts quite a long time, and at the same time reliably protects the home;
An environmentally friendly product that does not harm human health;
Even a small layer provides good thermal insulation.

These were the most common materials for ceiling insulation. There are also many bulk mixtures that are used to insulate the ceiling at the initial stage of construction. For example, with expanded clay (see: We do the insulation of the ceiling with expanded clay ourselves).