Insulating walls outside with foam - the most detailed step-by-step instructions!

Do you want to get cozy and warm accommodation, the temperature in which does not depend on the vagaries of the weather? Then you should insulate the walls from the outside with foam. Not sure where to start and how to get started? In this case, study this article - it will give you answers to your questions.

Polyfoam, its advantages and disadvantages

For Let's start with the material that will be discussed in the article. Polyfoam is a polymer insulation produced in the form of white plates. The material has a pronounced granular structure, and each individual grain contains many voids filled with gas.

It is their presence that gives the foam excellent thermal insulation qualities. You can find out about other material properties from the table.

Table. Polyfoam - the main characteristics.

Characteristic	Value
Density	From 15 to 40 kg / m3, depending on the grade of material
Thermal conductivity	From 0. 038 to 0.042 W / m * K
Water absorption coefficient	0.02
Water vapor permeability coefficient	0.05
Range of permissible temperatures	From -50 ° С to + 75 ° С
Average service life	60 years

Important! When buying polystyrene, pay attention to the fact that it has flame retardant additives, and the pores in the grains contain incombustible carbon dioxide.

The advantages of foam include:

• low cost;
• good thermal insulation qualities;
• low weight;
• ease of handling and installation;
• unattractive for bacteria and fungi;
• high durability.

As for the shortcomings of foam, there are two of them. The first is the flammability of the material. The second is low vapor permeability, which, in the event of a design or installation error, can lead to mold on the main wall.

The main task performed by insulation is to shift the dew point outward. Consider three options for buildings.

1. In the first case, there is only a wall without any insulation. The dew point is located inside the material, there is a significant temperature difference between its outer and inner sides. As a result, a lot of heat escapes through the wall, condensation forms in the house, and the service life of the material drops significantly due to dampness.
2. In the second case, the insulation is located from the inside. The dew point shifts to the area between it and the wall.

   Heat loss is significantly reduced, but dampness remains. There is also a risk of mold between the insulation and the wall.

3. In the third case, the insulation is located outside, the dew point is shifted behind the wall of the house. The latter is now not subject to dampness and does not lose heat.

Styrofoam prices

Polyfoam

Preparation of external walls for insulation

Construction work related to the insulation of the facade of the house with foam plastic begins with the preparation of the walls. They must be cleaned, leveled, primed, etc. All these steps are described in more detail in the step-by-step instructions below.

Step 1. For work above human height, construct a scaffold. You can make them yourself from the beams and boards available on the site, but it is safer to use factory-made products.

Scaffolding prices

Scaffolding

Step 2. Inspect the walls for various defects.

Seal cracks and holes, cut off the build-up of mortar. Prepare holes for water and gas pipelines and other utilities.

Step 3. Prime with deep wall penetration. Since the house in the example is composed of aerated concrete blocks, two layers will be required.

For the first time, the primer must be diluted by adding water from a third to half of the total volume.

Important! Priming in two layers is necessary not only for aerated concrete, but also for other porous materials such as foam blocks and sand-lime bricks.

Step 4. Apply a second coat of primer, but not diluted with water.

Thermal insulation of walls outside with foam - step by step instructions

After completing the preparation, proceed with the installation of expanded polystyrene boards.

In this case, their mounting on the wall will be combined - both glue and dowels with "umbrellas" are used.

The process itself will include:

• laying polystyrene foam for insulation on ordinary walls of the house;
• on window and door openings;
• on corners;
• on the space under the roof of the cottage.

For all processes from this list, separate step-by-step instructions have been compiled, which can be found in the subsections of the article presented below.

Working with ordinary walls

Let's start insulating the house outside with foam. Let's start with a relatively simple one - installing the first row of expanded polystyrene plates and laying them on ordinary walls.

Step 1. Measure how flat the walls of the house that you are insulating are, identify the presence of differences in thickness. To do this, use either a tensioned thread or a laser level.

Step 2. Set a mark at the bottom of the wall and draw a line from it , on which the first row of polystyrene foam boards will be laid.

Important! In this case, when insulating the walls from the outside, the foam is laid directly on the foundation - it is even enough for this. In other situations, install a special aluminum support profile before installing the expanded polystyrene boards.

Step 3. Mix the glue for installing the polystyrene foam insulation. To do this, dilute the dry mixture in water.

Select proportions based on the instructions printed on the glue package. Stir the solution using a mixer or drill with a suitable attachment, working at low speeds.

Step 4. Prepare EPS boards for the first row of insulation. In this case, a cutout is created in each of them, as in the diagram below.

Cut the polystyrene foam boards using a special table with a hot nichrome thread. In the absence of such equipment, use a hacksaw with a fine tooth.

Step 5. Apply the adhesive solution to the first block. To begin with, make a thin strip around the perimeter, pressing the trowel into the expanded polystyrene.

Then add more mortar, bringing the layer thickness to 25-30 mm. In the center of the block, apply several glue points, their number depends on the area of ​​the insulation element.

Prices for Ceresit glue

Ceresit glue

Step 6. Carry out a test installation of the expanded polystyrene block.

The purpose of the event is to find out what proportion of the total area is occupied by glue. To do this, lean the block against the wall and then set it back. Depending on the thickness of the insulation layer, the adhesive contact area should be 40-60% of the total.

Step 7. Prepare marks on paper or directly on the wall, according to which blocks of expanded polystyrene will be exhibited.

Lay the slabs according to the same principle as brickwork - the top row is shifted to the side relative to the bottom so that the vertical joints do not coincide. The permissible distance is from 15 cm, otherwise the seams will become "cold bridges". You can familiarize yourself with the layout of the foam blocks in the images below.

Step 8. Proceed with the installation of the first block - apply the adhesive on it as shown earlier, lean against the marked place and lean back.

Then align the position of the product. A thread stretched along the upper edge of the first row of blocks and a regular building level will help you with this.

Important! Use small pieces of Styrofoam to support the first row of blocks.

Step 9. Same principle as and in the previous step, lay the second, third and subsequent blocks of the first row.

Step 10. Then lay the remaining rows of foam insulation. You can read how to do this on corners and openings in the following subsections of the article. Dock the blocks tightly to each other, fill the gaps with expanded polystyrene glue, polyurethane foam or thin pieces of material.

Step 11.

After the glue or polyurethane foam has dried, with which you filled the joints between blocks, cut off the excess with a construction knife.

Step 12. Use the rule to determine how even the layer of insulation is. Grind the protruding areas with a special float.

Insulation of corners

Installation of insulation on the corners occurs according to the following scheme - from one of the sides, the block extends beyond the boundary of the wall at a distance equal to the thickness of the block installed on the second side.

On the next row, the order of arrangement of foam insulation elements changes to the strictly opposite. By a similar principle, the blocks are installed on the inner corners. For a better idea, check out the images below.

Now let's look at how the foam blocks are actually installed on the corners of the building.

Step 1. Mark out one of the foam blocks. Select the part that will go beyond the edge of the wall at the corner and the part that will be glued to the surface.

Step 2.

Apply the previously mixed mortar to the part of the block that is glued to the wall at the corner. Perform this operation carefully - the glue should not get on another part of the product, which you previously separated using the markings.

Step 3. Lean the block against the wall so that the glue adheres to the surface. Align horizontally and vertically, making sure to use a building level.

Building Level Prices

Building Levels

Step 4. Measure which block length you need for installation on another part of the corner. Cut off any excess with a fine-toothed hacksaw.

Step 5. Apply glue to the back of the Styrofoam and install the unit on the other side of the corner.

Dock it tightly with the item you installed a few operations ago.

Step 6. Cut off the protruding part of the first block using a hacksaw. At the end, you should end up with a right angle without any defects. If there is a gap between the blocks, then cover it with special foam glue or polyurethane foam.

Following the same principle as described in this manual, work with the rest of the outer and inner corners of the building.

Insulation of window / door openings and walls next to them

To begin with, let's consider by what principle the walls near the doorway are insulated. Here, the main task for you will be to ensure sufficient space for opening and closing. There are two options for installing the frame and door.

1. The door is installed flush with the outer side of the insulation layer.

   In this case, you need special fasteners for it and support in the form of channels. You can see the schemes of their installation in the image below.

2. The door is installed flush with the main wall. As a result, it turns out to be "recessed" in the insulation. To ensure the normal opening of the door, the polystyrene foam has to be sawed along the edges of the opening.

Imagine the process of laying the insulation near the doorway in the form of step-by-step instructions. In this case, an option is considered with the installation of the frame and the door itself at the level with the main wall.

Step 1.

Pick up the required number of blocks and file them off the edge with a fine-toothed hacksaw.

Step 2. Install the frame in the doorway if it has not been done earlier.

Step 3. Degrease the surface of the door frame.

Step 4. Prepare the required number of profiles for thermal insulation of openings. Unpack them, measure and cut. In this case, the edges of the profile, adjacent to the corners of the openings, must be cut at an angle of 45 °.

Step 5.

Remove the protective tape from the adhesive layer of the profile and fix it on one side opening. Make sure the profile fits snugly against the surface.

Step 6. Glue the profiles on the other sides of the opening using the same principle. In the corners, join them tightly to each other with cuts made at an angle of 45 ° in one of the previous stages of work.

Step 7. Prepare the strips of glass mesh. Their width should be equal to the thickness of the insulation layer plus 10 cm for fixing on the main wall. In this case, the strip is cut from a single net roll.

Step 8.

Apply a strip of adhesive mixture 10 in width along the perimeter of the opening see

Step 9. Place one of the edges of the strip of glass mesh on the applied the previous step is glue. Press the material to it, literally "drown".

Step 10. Apply more on top of the part of the mesh leaning against the wall one layer of glue.

Step 11. Repeat the previous operations with the mesh for the other sides of the doorway ...

Step 12.

Install the foam blocks with cut edges along the perimeter of the opening.

The situation with window openings is approximately similar - the block itself with a frame and glass can be installed both in the depth of the opening, and on its edge. In the first case, a gap appears between the outer layer of insulation and the window, which is closed with narrow strips of foam plastic. They are glued to the inner surfaces of the opening.

In the second version, the window is mounted on the edge of the opening, adjoining the frame to the insulation layer on the outer wall. This method is more effective in terms of thermal insulation.

It should also be said that the joints of expanded polystyrene blocks should not coincide with the joint of the window block with an opening.

Therefore, along the perimeter, the insulation is installed in the form of products with L-shaped notches. There are two options for how to do this, and they are presented in the images below.

The process of wall insulation with foam plastic near window openings is in many ways similar to that for a doorway. Here's a step-by-step guide.

Step 1.

Install the window unit, move it closer to the edge of the opening and fix it well there.

Step 2. Remove the protective film from the frame and degrease it.

Step 3. Stick a special profile around the frame perimeter.

Step 4. Apply a strip of adhesive 10 in width along the perimeter of the profile on the wall mm.

Step 5. On the glue applied in the previous step, fix the glass mesh strip along the same principles as for the doorway.

Step 6.

Saw the blocks in accordance with the diagrams outlined in the images in this section of the article.Secure around the perimeter of the opening.

Important! While fixing the foam under the window opening, make a slight tilt necessary to install the ebb.

As for the space under the roof, this is different from working with conventional walls is that it is necessary to pre-cut blocks with different and complex shapes from the foam.

Installation of fixing umbrellas on foam

For more For reliable connection of the insulation layer with the main wall, fixing "umbrellas" are used, also known as disc dowels.

Step 1. Determine the length of the disc dowel you need. It consists of the thickness of the insulation layer (in this case it is 200 mm), the adhesive layer (15 mm), the length of the expansion part of the dowel (60 mm) and another 20 mm of the reserve. Also, decide on which of the schemes shown in the image below, you will mount the fasteners.

Step 2.

Unpack the disc plugs, check if the parameters of the product correspond to those you need.

Step 3. Prepare the drill with a hole depth stop, adjust the latter to your desired values.

Step 4. Mark the points for the disk dowels and drill holes there.

Step 5. Insert the foot of the disk dowel into the hole so that the head is on flush with the foam surface. Then use a special drill bit and screw the spacer part of the fastener, then close it with a protective cap.

In some disc dowels, the spacer is not twisted, but hammered. You can see an example of how to work with them in the images below.

Some builders believe that disc dowels in foam insulation are "cold bridges". They fight this problem in the following way: using a special cutter, they cut a cylindrical recess in expanded polystyrene, insert fasteners there and fix it. Then the disc dowel is closed with the foam cover cut out earlier.

Prices for popular models of rotary hammers

Rotary hammers

Video - Insulation of the cottage facade with expanded polystyrene

Reinforcement of insulation

On the installation of expanded polystyrene blocks the process of wall insulation from the outside is not completed - the material must be protected with a reinforcing mesh and plaster mixture.

Step 1.

Prepare a plaster-adhesive mixture of dry powder and water. Choose the proportions based on the recipe printed on the package. Mix the mortar with a construction mixer.

Step 2. Start working with windows and doors.

On the inner surface of their openings, apply a thin layer of plaster and glue mixture and level it.

Step 3. Press the reinforcing mesh laid on the inner surface of the openings in one of the previous sections of the article to the glue mixture and sink in it. Smooth over everything with a rectangular trowel.

Step 4.

Exactly in the same way as in the previous operation , press the mesh belonging to the previously installed profile to the adhesive layer and drown it.

Step 5. Repeat the previous three steps with all sides of the window opening ...

Step 6. Apply stripes on the corners near the openings adhesive mixture at an angle of 45 °. Then lay the reinforcing mesh on them and smooth it with a trowel. Such areas near openings are called "kerchiefs".

Step 7.

Measure a corner profile to the desired length. Apply a layer of glue mixture along the outer perimeter of the window, then lean the profile with the mesh against it and the inner surface of the opening and smooth with a rectangular trowel.

Step 8. Using the same principle, install the corner profiles on other surfaces of the window opening.

Step 9.

Apply to the inner corners of the opening a small rectangle or square of reinforcing mesh, straighten and smooth with an adhesive mixture.

Step 10. Repeat steps two to nine for each individual window and door opening.

Step 11. Apply glue solution around the perimeter of the house to the bottom of the insulation.

Then attach the drip profile there. Install it so that no air pockets remain between it and the insulation. Control the process with a building level.

Step 12. Apply another layer of plaster over the mesh of the drip profile and smooth with a rectangular trowel.

Step 13. Following the same principles as described above, perform installation of the corner profile - apply an adhesive layer, attach the product to it, sink it into the mesh and smooth everything on top.

Step 14. Now proceed to reinforce the entire surface of the walls. Cut lengths from the roll with a net to match the height of the insulated walls of the house.

Step 15. On top of the expanded polystyrene, apply a layer of plaster-adhesive mixture and smooth with a toothed ironer.

Step 16. Lay a reinforcing mesh on top of the adhesive layer , press it down and brush on top with another layer of mortar. Smooth everything thoroughly - irregularities and cavities with air are unacceptable.

Step 17. In the same way, lay the next section of the mesh side by side. There must be at least 100 mm overlap between it and the previous one.

Step 18. Give the glue mixture a little (but not completely!) dry and scrape off any irregularities.

Step 19. Using the rule, search for concavities on the adhesive layer applied over the insulation ... Then line them up by adding a little more mixture in the right places.

Step 20. After the finally hardened adhesive mixture, make another leveling of the surface - puttying.

Facade foam plaster

The easiest way to insulate a house is to sheathe it with foam. The material is inexpensive, installation is easy to do on your own, the energy-saving effect is obvious. And in order to protect such a sheathing from the harmful effects of the environment, you need to choose a suitable coating for it.

Read more here.

After the putty hardens, the outside wall insulation with foam plastic can be considered complete.Next, you just have to apply a finishing decorative finish in accordance with your tastes and preferences.