The main type of utility expense for residents of the private sector is heating. It’s easy to cut costs by insulating your house with polystyrene foam on the outside with your own hands. This material will not only save you from the cold in winter, but also keep your room cool in summer. In addition, it will maintain the integrity of the walls of buildings. It is possible to do such work with your own hands, you just need to select the right materials and not deviate from the technological map.
Choosing polystyrene foam
Foam plastic is the simplest and most convenient material for use. facade insulation, decorating external walls with it will not be difficult. Manufacturers suggest using polystyrene foam in two types of slabs to carry out such work with your own hands:
- Foamed. It consists of plastic balls filled with air using thermoforming. They are connected using a press or non-press method. Can be of different densities: from 11 to 35 kg/m3. Can be used as insulation for building facades.
- Extruded. In production, the extrusion technique is used - pressing the molten mass through the molding hole of a special apparatus (extruder) under the influence of high temperatures. The dense, finely porous structure makes the material practically waterproof. Therefore, thermal insulation of the basement, plinth, blind area and foundation does not require additional protection from moisture. For the walls of a private house they are used only with an ideal ventilation system.
Pros and cons of each type
Which material is better? Insulating walls with foam plastic from the outside involves the use of specially designed slabs. The most suitable for do-it-yourself installation is façade polystyrene foam of the PSB-S M-25F brand. Its density is 25kg/m3. You can purchase material of a higher density, but lower density is not possible. Insulating facades with lightweight polystyrene foam is undesirable; although it costs much less, it loses in design indicators: water resistance, vapor permeability, heat protection, durability.
You can correctly determine the strength of a sheet visually: the smaller and denser the granules, the higher it is. The looseness of the structure is especially clearly visible on the cut. As for the extruded look, it is better to choose slabs with L-shaped edges. Although they are more expensive, they prevent the formation of “cold bridges” that reduce thermal conductivity and destroy the building.
In order not to be deceived and not to purchase low-quality material, pay attention to the presence of factory markings on the ends of the sheets, fire and sanitary certificates, and GOST indicators in the quality passport.
Preparing the building for cladding work
What needs to be done before insulating the facade of a house with polystyrene foam correctly? The first step is to clean the walls from dirt and make them as smooth as possible. Permissible differences from the plane - concavity and convexity - should not exceed two centimeters, so that in the event of an accidental impact, deformation of the sheet does not occur. If possible, the paint from the wall should be completely removed, rust spots. If there are metal parts, coat them with an anti-corrosion agent.
It’s easy to check the wall’s readiness for cladding by running your palm over it. If small particles fall off, you need to continue cleaning the surface. If this does not help, you should prime the surface or apply a thin layer of putty with PVA glue. It is better to apply the primer with a brush, but if it is very liquid, you can use a sprayer.
Do-it-yourself façade finishing using regular sheets foam type does not require preparation. As for extruded ones, they need to be processed for better adhesion to the wall surface. You can use a needle roller for drywall, hard wire brush or a simple stationery knife, which is used to cut small grooves. It is even easier to purchase corrugated slabs, but such material is more expensive.
It is advisable to sew up the external slopes with your own hands and install flashings before installing polystyrene foam boards on the façade of buildings. For the first, choose sheets that are thinner than for the main work. The insulation should extend beyond the slopes by about 2 cm. Then use it façade cladding docks quickly and accurately.
You should not cut sheets of expanded polystyrene on slopes flush with the facade wall. It is recommended to leave a protrusion for better joining with the main plates when installing it yourself.
Installing foam boards
The technology for insulating walls with foam plastic from the outside is divided into stages; do-it-yourself installation must be done sequentially.
Stage one - gluing the plates
Finishing begins immediately upon completion of the cladding of slopes and ebbs. How to properly install slabs on glue with your own hands:
It is important to know
When finishing with foam plastic is carried out, standards fire safety require the installation of special fire protection belts made of non-flammable mineral wool around window and door openings.
Stage two - securing with dowels
Before strengthening the insulation, you need to wait until the glue hardens. Otherwise, the sheets along the edges may begin to move away from the wall surface. Then you need to correctly perform the following operations:
- They improve the adhesion of the insulation to the wall with the help of mushroom dowels. They are hammered into pre-drilled holes to a depth of at least five centimeters. This must be done so that the dowel head is flush with the surface of the slab. Professionals recommend placing five “fungi” on each edge of the sheet and one in the center.
- Nails are driven into the “heads” of the dowels. If the heads stick out a little, you need to trim them with pliers.
- If there are gaps in the seams, you need to fill them with strips of polystyrene foam. Small cracks can be foamed with a special compound. Protruding joints are smoothed with a special grater or cut off with a stationery knife.
- At the end of this stage, the dowel caps and joints are treated with a special compound.
Stage three - installation of the grid
When insulating the facade with polystyrene foam yourself, you must definitely increase the mechanical strength of the structure using a special facade mesh based on fiberglass. The mesh for reinforcing walls must be chosen dense and hard, and for corners, slopes and decorative parts - soft. It is recommended to strengthen all corner elements of the house with perforated aluminum corners.
After this, glue is applied to the surface of the slabs in a continuous layer approximately two to three millimeters thick. The reinforcing material is fixed at the top, then rolled down and immersed with a spatula in adhesive composition. Each blade should overlap the adjacent one by about five centimeters, and at the corners you need to bend by no less than fifteen centimeters. The base is reinforced in two layers.
Apply another layer of glue on top of the canvas and carefully smooth the surface. As a result, the mesh should only show through the glue a little.
The final stages include treatment with a primer and subsequent finishing. It is correct to carry them out no less than two days after installing the façade mesh. You can decorate the walls with putty for painting or special plaster. Exist various techniques plastering, such as fur coat or bark beetle.
You should also know that in addition to technology wet facade There are also ventilated facades, but the use of polystyrene foam in structures of this type is not recommended, since rising air currents can contribute to the combustion of polystyrene foam.
Do you want to get cozy and warm housing, the temperature in which does not depend on the vagaries of the weather? Then you should insulate the walls outside with polystyrene foam. Don't know where to start and how to get started with this work? In this case, study this article - it will give you answers to your questions.
First, let's get acquainted with the material that will be discussed in the article. Polystyrene foam is polymer insulation, produced in the form of plates white. The material has a pronounced granular structure, with each individual grain containing many voids filled with gas. It is their presence that gives the foam excellent thermal insulation qualities. You can see other properties of the material in the table.
Table. Foam plastic - main characteristics.
Important! When buying polystyrene foam, pay attention to the fact that it has fire retardant additives, and that the pores in the grains contain non-flammable carbon dioxide.
The advantages of polystyrene foam include:
- low cost;
- good thermal insulation qualities;
- low weight;
- ease of processing and installation;
- unattractive to bacteria and fungus;
- high durability.
As for the disadvantages of polystyrene 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 an error in the design or installation of insulation, can lead to the appearance of mold on the main wall.
The main task performed by insulation is to shift the dew point outward. Let's consider three options for buildings.
- 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 decreases significantly due to dampness.
- In the second case, the insulation is located from the inside. The dew point moves to the area between it and the wall. Heat loss is significantly reduced, but dampness remains. There is also a risk of mold growing between the insulation and the wall.
- In the third case, the insulation is located outside, the dew point moves behind the wall of the house. The latter is now not subject to dampness and does not lose heat.
Prices for foam plastic
Styrofoam
Preparing external walls for insulation
Construction work related to insulating the facade of a house with foam plastic begins with preparing the walls. They need to be cleaned, leveled, primed, etc. All these steps are described in more detail in the step-by-step instructions below.
Step 1. To work at heights exceeding human height, build scaffolding. You can make them yourself from timber 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, sagging mortar chip it off. Prepare openings for water and gas pipelines and other utilities.
Step 3. Prime with primer deep penetration walls. Since the house in the example is made 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! Primer treatment in two layers is necessary not only for aerated concrete, but also for other porous materials, such as foam blocks and sand-lime brick.
Step 4. Apply a second coat of primer, but not diluted with water.
After completing the preparation, proceed to laying the polystyrene foam 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 expanded polystyrene for insulation on ordinary walls of the house;
- on window and door openings;
- on the corners;
- to 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 regular walls
Let's start insulating the outside of the house with polystyrene foam. Let's start with a relatively simple one - installing the first row of polystyrene foam boards and laying them on ordinary walls.
Step 1. Measure how smooth the walls of the house you are insulating are and identify any differences in thickness. To do this, use either a stretched thread or a laser level.
Step 2. Place a mark at the bottom of the wall and draw a line from it along 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 level enough for this. In other situations, install a special aluminum support profile before installing polystyrene foam boards.
Step 3. Mix the glue to install the polystyrene foam insulation. To do this, dilute the dry mixture in water. Choose proportions based on the instructions printed on the glue package. Stir the solution using a mixer or drill with an appropriate attachment, working at low speed.
Step 4. Prepare polystyrene foam boards for the first row of insulation. In this case, a cutout is created in each of them, as in the diagram below. Cut polystyrene foam boards using a special table using a hot nichrome thread. If such equipment is not available, use a hacksaw with small tooth.
Step 5. Apply to the first block glue solution. To begin, make a thin strip around the perimeter by pressing the trowel into the polystyrene foam. Then add more solution, bringing the layer thickness to 25-30 mm. Apply several glue dots in the center of the block, their number depends on the area of the insulation element.
Applying a second layer, more voluminous. Be careful when working with it - the glue should not get on the ends of the foam block
Prices for Ceresit glue
Ceresit glue
Step 6. Perform a test installation polystyrene foam 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 On paper or directly on the wall, prepare marks along which the polystyrene foam blocks will be placed. Lay the slabs according to the same principle as brickwork - the top row is shifted towards the bottom row so that the vertical seams do not coincide. The permissible distance is from 15 cm, otherwise the seams will become “cold bridges”. You can see the layout of the foam blocks in the images below.
Step 8 Proceed to laying the first block - apply the adhesive composition to it as shown earlier, lean it against the marked place and lean it against it. Then level 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 foam as pads to support the first row of blocks.
Step 9 Using the same principle as 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 about how to do this at corners and openings in the following subsections of the article. Join the blocks tightly together, fill the gaps with polystyrene foam glue, polystyrene foam or thin pieces material.
Step 11 After the glue or polyurethane foam that you filled the joints between the blocks has dried, cut off the excess with a construction knife.
Step 12 Using the rule, determine how even the insulation layer is. Sand the protruding areas with a special grater.
Insulation of corners
Installation of insulation on the corners occurs according to the following scheme - on one side the block extends beyond the wall boundary 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 exactly the opposite. Using a similar principle, blocks are installed on internal corners. For a better idea, check out the images below.
Now let's look at how foam blocks are actually installed on the corners of a building.
Step 1. Mark one of the foam blocks. Select the part that will extend beyond the wall at the corner and the part that will be glued to the surface.
Step 2. Apply the previously mixed solution 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 that you previously separated using markings.
Step 3. Place the block against the wall so that the glue adheres to the surface. Align horizontally and vertically, and be sure to use a building level.
Prices for building levels
Construction levels
Step 4. Measure how long a block you will need to install on the other side of the corner. Cut off the excess with a fine-toothed hacksaw.
Step 5. Apply glue to the back surface of the foam and install the block on the other side of the corner. Connect it tightly to the product that you installed several operations ago.
Step 6. Cut off the protruding part of the first block using a hacksaw. At the end you should have a right angle without any defects. If there is a gap between the blocks, then cover it with special glue for polystyrene foam or polyurethane foam. Using the same principle as outlined in this instruction, work with the remaining external and internal corners of the building.
Insulation of window/door openings and walls next to them
First, let's look at the principle by which walls are insulated near a doorway. Here main task you will be provided with sufficient space for opening and closing. There are two options for installing the frame and door.
- The door is installed flush with the outside of the insulation layer. In this case, you need special fasteners for it and supports in the form of channels. You can see their installation diagrams in the image below.
- The door is installed flush with the main wall. As a result, it turns out to be “recessed” in the insulation. To ensure normal opening of the door, the polystyrene foam along the edges of the opening has to be filed.
Let's present the process of laying insulation near a doorway in the form of step-by-step instructions. In this case, the option of installing the frame and the door itself at a level with the main wall is being considered.
Step 1. Pick up required quantity blocks and saw them off the edge with a regular hacksaw with fine teeth.
Step 2. Install a frame in the doorway if this has not been done previously.
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 them. 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 secure it to one side of the opening. Make sure that the profile fits tightly to the surface.
Step 6. Using the same principle, glue the profiles to the other sides of the opening. In the corners, tightly join them to each other with cuts made at an angle of 45° at one of the previous stages of work.
Step 7 Prepare strips of fiberglass mesh. Their width should be equal to the thickness of the insulation layer plus 10 cm for fastening to the main wall. In this case, the strip is cut from a single roll of mesh.
Step 8 Along the perimeter of the opening, apply a 10 cm wide strip of adhesive mixture to the wall.
Step 9 Place one of the edges of the fiberglass mesh strip against the glue applied in the previous step. Press the material against it, literally “drown it.”
Step 10 Apply another layer of glue on top of the part of the mesh leaning against the wall.
Step 11 Repeat the previous mesh operations for the other sides of the doorway.
Step 12 Install foam blocks with cut edges around the perimeter of the opening.
The situation with window openings is approximately similar - the block itself with frame and glass can be installed both in the depth of the opening and at 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 laid on glue in the inner surfaces of the opening.
In the second option, the window is mounted on the edge of the opening, with the frame adjacent to the insulation layer on external wall. Similar method more effective from a thermal insulation point of view.
It is also worth saying that the joints of polystyrene foam blocks should not coincide with the joint of the window block with the opening. Therefore, along the perimeter, insulation is installed in the form of products with L-shaped cutouts. There are two options for how to do this, and they are presented in the images below.
The process of insulating walls with foam plastic near window openings in many ways resembles that for a doorway. Here are step-by-step instructions.
Step 1. Install window unit, move it closer to the edge of the opening and secure it well there.
Step 2. Remove protective film from the frame and degrease the latter.
Step 3. Glue a special profile around the perimeter of the frame.
Step 4. Apply a 10 mm wide strip of glue along the perimeter of the profile to the wall.
Step 5. Using the glue applied in the previous step, attach a strip of fiberglass mesh according to the same principles as for the doorway.
Step 6. Cut out the blocks in accordance with the diagrams shown in the images in this section of the article. Secure around the perimeter of the opening.
Important! When fixing the foam under the window opening, make the slight slope necessary to install the ebb.
As for the space under the roof, this is different from working with ordinary walls consists in the fact that it is necessary to first cut blocks of different and complex shapes from foam plastic.
Installation of mounting umbrellas on foam plastic
For a more reliable connection of the insulation layer to the main wall, fastening “umbrellas”, also known as disc dowels, are used.
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 spacer part of the dowel (60 mm) and another 20 mm reserve. Also decide which of the diagrams shown in the image below will be used to mount the fasteners.
Step 2. Unpack the disc dowels and check whether the product parameters match those you need.
Step 3. Prepare a drill with a hole depth limiter, adjust the latter to the value you need.
Step 4. Mark the locations of the disc dowels and drill holes there.
Step 5. Insert the foot of the dowel into the hole so that the head is flush with the surface of the foam. Then use a special attachment on the drill and tighten the spacer part of the fastener, and then close it with the protective cap.
In some disc dowels, the spacer element is not screwed in, but is 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 deal with this problem in the following way: using a special cutter, they cut out a cylindrical recess in polystyrene foam, insert fasteners there and fix it. The disc dowel is then covered with the foam cap that was cut out earlier.
Prices for popular hammer drill models
Hammers
Video - Insulating the façade of a cottage with polystyrene foam
Insulation reinforcement
The installation of expanded polystyrene blocks does not complete the process of insulating the walls from the outside - the material must be protected using reinforcing mesh and plaster mixture.
Step 1. Prepare a plaster-adhesive mixture from dry powder and water. Choose proportions based on the recipe printed on the package. Mix the solution with a construction mixer.
Step 2. Start with windows and doors. Apply a thin layer of plaster-adhesive mixture to the inner surface of their openings 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, onto the adhesive mixture and drown it in it. Smooth the entire top with a rectangular trowel.
Step 4. In exactly the same way as in the previous operation, press the mesh from earlier onto the adhesive layer. established profile, and drown her.
Step 5. Repeat the previous three steps on all sides of the window opening.
Step 6. At the corners near the openings, apply strips of adhesive mixture at an angle of 45°. Then lay the reinforcing mesh on them and smooth it with a trowel. Such areas near the openings are called “kerchiefs”.
Step 7 Measure the corner profile required length. Apply a layer of adhesive mixture along the outer perimeter of the window, then lean it against it and inner surface opening profile with a mesh and smooth it with a rectangular trowel.
Step 8 Using the same principle, install corner profiles on other surfaces of the window opening.
Step 9 TO internal corners Apply a small rectangle or square of reinforcing mesh to the opening, straighten it and smooth it with the adhesive mixture.
Step 10 Repeat steps two through nine for each individual window and door opening.
Step 11 Apply the adhesive solution around the perimeter of the house to the bottom of the insulation. Then attach the drip profile there. Install it so that there are no air cavities between it and the insulation. Control the process using a building level.
Step 12 Apply another layer of plaster over the drip profile mesh and smooth it with a rectangular trowel.
Step 13 Using the same principles as outlined above, install the corner profile - apply an adhesive layer, attach the product to it, press it into the mesh and smooth everything on top.
Step 14 Now proceed to reinforce the entire surface of the walls. Make sections from a roll of mesh with a length corresponding to the height of the insulated walls of the house.
Step 15 Apply a layer of plaster-adhesive mixture on top of the polystyrene foam and smooth it with a notched trowel.
Step 16 Place a reinforcing mesh sheet on top of the adhesive layer, press it down and cover it with another layer of mortar on top. Smooth out everything carefully - unevenness and cavities with air are unacceptable.
Step 17 Lay the next piece of mesh side by side in exactly the same way. There must be an overlap of at least 100 mm between it and the previous one.
Step 18 Let the adhesive mixture dry a little (but not completely!) and scrape off any irregularities.
Step 19 Using the rule, search for concavities in the adhesive layer applied over the insulation. Then level them out by adding a little more mixture in the right places.
Step 20. Using the finally hardened adhesive mixture, level the surface again - using putty.
The easiest way to insulate a house is to cover it with polystyrene foam. The material is inexpensive, installation is easy to do on your own, and the energy-saving effect is obvious. And in order to protect such cladding from the harmful effects of the environment, you need to choose a suitable coating for it. Read more.
After the putty has hardened, the insulation of the walls from the outside with polystyrene foam can be considered complete. Next, all you have to do is apply the final decorative finish in accordance with your tastes and preferences.
In order for the house to be warm, it needs to be insulated correctly, taking into account not only the thickness of the foam, but also the technology itself, following which you can achieve best results for insulating the external walls of your facade. We invite you to read the detailed step-by-step instructions complete with photos.
Before starting insulation work, it is necessary to carefully check and prepare the base. Walls intended for gluing foam plastic must be stable, dry, free of dirt, dust, old peeling paint and other contaminants that reduce the adhesion of the adhesive solution. In an ideal way wall cleaning is by pressure water cleaning or mechanical cleaning (for example, using wire brushes or grinding machines). In case of large accumulations of moss and algae, the use of biocides is recommended.
Leveling the base
When assessing the foundation, monitoring its condition is very important. Using a hammer, you can find a dull sound indicating peeling of the plaster. You must remove such a fragment and plaster the resulting cavity. It is also recommended to beat off the plaster with outside slopes of window and door openings, thus allowing the slopes to be insulated with polystyrene foam 3 to 5 centimeters thick. If there are coatings on the substrate, such as paint, it should be checked bearing capacity, scratching with a sharp tool or gluing with tape. If partial separation occurs old paint, the base should be considered weak and must be thoroughly cleaned. If unevenness or depressions larger than 10 mm occur, they must be leveled using a leveling solution.
Surface primer
Dusty walls should be primed with a deep penetration primer before gluing the foam.
Checking the strength of the base
If you doubt the strength of the wall surface, you should conduct an adhesion test. For this purpose, we glue 8-10 samples of polystyrene foam measuring 10 x 10 cm in different places onto a properly prepared surface. To glue foam samples, a solution of a 10 mm thick layer of glue is used. Foam samples with the applied solution should be pressed to specially designated areas on the wall surface. After a minimum of 3 days, an attempt should be made to manually tear off the glued foam. If a rupture occurs in polystyrene foam, this indicates sufficient strength of the base and adhesion of the adhesive. If samples of polystyrene foam come off the wall surface along with a layer of adhesive mass, this means that the walls were not properly prepared or that the top layer does not have sufficient strength.
Installation of the base profile
Before gluing the foam boards, it is necessary to secure the base profiles. To do this, you need to determine the height of the base using a tapping cord and make marks on the base. Then secure the profiles with dowels - on average 3 pieces are used. on linear meter. If the wall is uneven, pads should be used. It is recommended to connect profiles using special mounting clips. Plinth profiles, in addition to determining the level and facilitating the installation of thermal insulation materials, are responsible for protecting thermal insulation from open fire, dampness and destruction, insects, birds or rodents.
When installing plinth profiles on the internal or external corner of the building, it is worth paying attention Special attention for correct installation (see photo). It is also possible to use special connectors.
Preparation of the adhesive solution
Before gluing the foam, you should properly prepare the adhesive solution. To glue the foam, use an appropriate adhesive solution. Mix the contents of the bag thoroughly with about 5.5 liters of clean, cold water using a low-speed drill with an appropriate stirrer. After obtaining a homogeneous mass without lumps, wait about 10 minutes and mix again before using. The prepared solution is suitable for use for a period of 2.5 to 3 hours. During work, it is necessary to periodically stir the solution approximately every 30 minutes. It is not allowed to add water to the prepared solution in order to “improve” its consistency.
Applying the solution to polystyrene foam
Depending on the type of base, the adhesive solution can be applied to the foam in several ways. In the case of insulation of a flat surface, the adhesive solution is applied to the slabs using a notched grater with a tooth size of 10-12 mm. In other cases, the solution should be applied using the “circumference-point” method, i.e., using a trowel along the contour of the slab in a strip about . 3-4 cm and additional cakes in the amount of 3-8 pieces. The size of the cakes should depend on their quantity. The amount of glue located on the edge should be enough so that after pressing the slab, the adhesive solution does not go beyond its boundaries. It is necessary to ensure that the adhesive solution covers at least 40% of the surface of the slab (see the photo for the correct application of glue to the foam).
Bonding foam boards around window and door openings
Near window and door openings, slabs should be selected (cut) so that the horizontal and vertical seams between the slabs do not coincide with the edges of the holes (see photo). This arrangement will prevent cracks in the finish in the future.
Control of the plane of glued foam plastic
Please note that during the process of gluing the foam, the level and evenness of the entire surface is maintained using a plumb line or level.
Filling gaps between slabs of thermal insulation material
Gaps between the boards of more than 2 mm should be filled with strips cut from foam boards. In case of gaps smaller than 4 mm in systems using polystyrene foam boards, it is also possible to fill them polyurethane foam. It is not allowed to fill the joints with mortar, which is used for gluing slabs, due to the occurrence of cold bridges, as well as the risk of cracks appearing along the joints of the slabs.
Leveling the surface of glued foam plastic
Foam boards after gluing should be flat surface. Protruding irregularities (bumps) should be sanded with a special grater or sandpaper. The surface of the slabs can be sanded no earlier than 72 hours from the moment they are glued.
Fastening foam plastic using a dowel umbrella
If it is necessary to use additional protection of the foam from tearing, i.e. when the tensile strength of the base is less than 0.08 MPa or the height of the building exceeds 20 m, mechanical connections, a dowel with a plastic or metal umbrella, should be used.
Drilling holes and installing dowel umbrella
Installation of dowels can begin no earlier than 3 days after gluing the polystyrene foam boards, that is, after the adhesive solution has set.
It is believed that the depth of penetration of the rod deep into the wall should be:
- minimum 5-6 cm - dense base (concrete, brick, sand-lime brick or stone);
- minimum 8-9 cm - porous base (aerated concrete, hollow brick and shell rock).
The number of dowels for foam plastic is from 4 to 6 pcs/m². When determining the length of the dowels, you need to take into account the thickness of the old plaster, the adhesive layer and the thickness of the thermal insulation material. It should be borne in mind that, despite the load-bearing capacity of the foundation, in the case of buildings with a height of more than 20 m, mechanical connections must be used. The edge zones of the building, where the greatest forces caused by the wind occur, i.e., from 1 to 2 m from the edge, the insulation project should provide for an increased number of dowels in these places.
Installation of dowel umbrellas
The dowel rods should not protrude beyond the plane of the umbrella. The ideal option to prevent the formation of cold bridges is to mill holes to a depth of 2 cm, into which the umbrella dowel is recessed. Then the space above it should be covered with the remaining foam. The wrong thing to do is to sink the umbrella with a hammer. Excessive deepening of the umbrella in the material can lead to the appearance of cracks (rupture) of the umbrellas, which as a result weakens the load-bearing capacity of the system.
Preparation of glue for foam reinforcement
To perform a layer, mesh reinforced fiberglass in a polystyrene foam system, it is necessary to use an adhesive solution designed for reinforcing foam boards. The entire contents of the bag should be thoroughly mixed with the appropriate amount clean water using a low-speed drill equipped with a stirrer. Then the mass should be kept for about 10 minutes and mixed again. It is recommended to periodically stir the solution every 30 minutes. Depending on the temperature, the solution is usable for approximately 2.5 to 3 hours. You cannot add water to the prepared solution in order to “improve” its consistency.
The glue is applied to the foam in a continuous layer about 3mm thick. To apply the solution, use a notched trowel with a tooth size of 10-12 mm. The adhesive solution is applied vertical stripes width of fiberglass mesh.
Embedding fiberglass reinforcement mesh
After applying the adhesive solution to the mesh, it is necessary to carefully press it down, starting from the top, pressing it along its entire width. The mesh should be evenly stretched over the entire surface, without waves, humps or bulges. To ensure proper functioning of the layer, the reinforcing mesh must be recessed in the middle of the thickness of the solution. It is not allowed to attach reinforcing mesh directly to umbrellas or glue applied with a trowel. Immersion of the mesh too deep or too shallow can lead to cracking and the formation of humps in the reinforcement layer. The thickness of the solution layer when using one mesh should be from 3 to 5 mm.
When embedding the mesh into the mortar layer, you should pay attention to ensure that the vertical and horizontal edges of the mesh overlap each other by at least 10 cm. It is necessary to strictly follow the rules for wrapping the mesh on slopes and window sills and on wall corners - in the case of using protective corners without mesh - move the mesh to the adjacent wall by about 15 cm. If the walls of the building are subject to impacts and mechanical damage, taking into account their location, it is necessary to apply double mesh made of fiberglass along the entire height of the walls of the first floor. After the adhesive solution in which the first layer of fiberglass mesh was immersed has hardened, a second layer of solution should be applied and another layer of mesh should be sunk in it. The thickness of the layer reinforced with a double layer of mesh should be 6-8 mm.
The mesh must be carefully filled, since the leveling of the surface affects the final appearance of the facade. If irregularities occur, they must be sanded with sandpaper - otherwise they will be visible in the structure of the thin-layer plaster. Grinding can be done when the mortar layer is not yet too hard.
Application of paint and primer
After the reinforced layer has dried, no earlier than 3 days from its completion (this period can be extended in case of unfavorable weather conditions) in order to ensure optimal adhesion of the decorative plaster to the base, you can begin to apply primer paint. Work should be carried out at a temperature not lower than +5°C and not higher than +25°C, without precipitation. The primer should be applied using a brush or roller, remembering to apply it evenly over the entire surface. It is not recommended to dilute the primer paint due to the deterioration of its properties.
Application of decorative plaster
After the primer paint has dried, but not earlier than 24 hours after its application, you can begin applying decorative plaster. To prepare it, the entire contents of the package should be thoroughly mixed with approximately 5.0 liters of clean water until a homogeneous consistency is obtained. The prepared solution is left for 10 minutes and mixed again (without adding water). The solution prepared in this way is suitable for use for no longer than 1 hour.
Application of thin layer plasters
During the plastering works the requirements of the appropriate weather conditions must be observed, both during application and during the drying of the plaster: avoid rain, strong winds and strong sunlight. The optimum air temperature should be between 5°C and 25°C, and the relative humidity should not exceed 75%. Due to large temperature differences between day and night, plastering work is not recommended between November and March. In case of danger due to a temperature drop below 5°C, the drying time of the plaster (at least 48 hours from the moment of its application) should also not be carried out.
If these requirements are met, you can begin applying plaster to the pre-primed wall.
Apply plaster using a steel float thin layer by grain thickness. Then you should smooth the surface, collecting excess material. After some time, depending on the conditions encountered during the application process, we rub the plaster using a plastic float. In order to avoid a visible contact line between the fresh and already hardened layer of plaster, it is necessary to ensure a sufficient number of workers and scaffolding. When applying decorative plaster, avoid interruptions during the application of the layer and adhere to the main rule “wet on wet”. Due to increased absorption of thermal and ultraviolet radiation on facades located to the south and west, it is not recommended to use dark colors; the number of such colors on the surface of the facade should not exceed 10%.
Rubbing plaster
Rubbing the plaster should begin if the plaster mass does not stick to the plastic float. This time depends on the air and soil temperature, relative humidity and thickness of the material. To complete the texture, you need to use a plastic trowel and, depending on the structure of the plaster, we give it a suitable model. One thing to keep in mind is to press the grater with the same force while holding it at a constant angle.
Plaster type "bark beetle"
Plaster with a “bark beetle” type structure depends on the movements of the trowel. You can draw vertical, horizontal, diagonal or circular indentations of a certain width depending on the size of the crumb.
Painting plaster
The paint can be applied by brush, roller or mechanically by spraying, always in two layers. It is allowed to dilute the first layer of paint, especially if work is carried out at temperatures close to the maximum permissible (+25°C). For dilution silicate paints you should use a special primer (solvent) in an amount of up to 5%, and other paints can be diluted with clean water in an amount of up to 10%.
In the case of the second layer, the paint should be used undiluted. During work, you should adhere to appropriate weather conditions, i.e. avoid large amounts of sunlight, strong winds and precipitation. The optimum air temperature should be between 5°C and 25°C and the relative humidity should not exceed 75%
Advantages of insulating the walls of a house with polystyrene foam. How to choose the right insulation. “Wet” façade technology.
We insulate the house with polystyrene foam
The annual rise in energy prices and the desire to live in a cozy, warm home force owners of individual real estate to quickly insulate their buildings.
The article tells you how to choose the right polystyrene foam and insulate the walls yourself, what tools and consumables you will need.
Advantages and disadvantages
Foamed polystyrene - synthetic material, the positive properties of which make it an excellent insulation material. Advantages compared to other materials:
- Small specific gravity. One cubic meter foamed polystyrene weighs from 11 to 40 kg. This amount of material with a sheet thickness of 50 mm is enough to insulate 20 square meters. m. walls.
- Insignificant price compared to other insulation materials.
- Low thermal conductivity, contributing to energy saving in heating season and keeps you cool in summer.
- High levels of noise insulation, providing comfortable conditions in houses located along busy streets.
- Strength sufficient for mounting plates in a variety of ways.
- Easy installation.
- Available at any hardware store.
Among the shortcomings are noted:
- low vapor permeability;
- toxicity when heated;
- necessity exterior finishing to protect against direct impact sunlight (foam is destroyed by ultraviolet radiation).
What are the parameters for choosing polystyrene foam?
When choosing polystyrene foam, take into account the physical and technical characteristics that contribute to the performance of the functions assigned to the insulation:
- preservation of heat (coolness);
- ease of installation;
- the chosen method of insulation;
- environmental friendliness for nature and safety for human health.
Let's take a closer look at the characteristics.
Slab thickness
In stores you can find sheets with a thickness of 10 to 100 mm in increments of 10 mm. The choice of thickness depends on the region and purpose of the building. Sheets of 40, 50, 100 mm are in demand and most often found in retail outlets, but the manufacturer is ready to produce products of 20, 60, 70, 80 up to 500 mm to order. The price will remain the same, calculated per cubic meter.
To simplify understanding, on average, foamed polystyrene with a thickness of 10 cm retains heat in the same way as timber with a thickness of 45 cm, foam concrete masonry with a thickness of 73 cm, Brick wall 150 cm or concrete 300 cm. This is enough to insulate walls in any region of the country.
Size
It is more difficult to choose the length and width of the sheets. Accepted here standard sizes 500x1000, 1000x1000 and rarely 1000x2000 mm. For installing insulation around windows and doorways The sheets are cut with a sharp knife or a file with fine teeth.
For large objects, electric cutters are purchased and made independently - this way the material crumbles less and the edges remain smooth, which is convenient for further finishing.
Density
The main parameter characterizing the scope of application is density.
For use in construction, manufacturers produce products of three varieties, which are conventionally designated by numbers in the name - 15, 25, 35. Their brief Comparative characteristics is given in the table.
Table. Characteristics of different brands of polystyrene foam.
The low density of PSB-S-15 foam makes the sheets “loose” and easily destroyed. Small mechanical impact causes damage and leaves dents.
If we compare thermal conductivity, then the values for different types foam polystyrene do not differ much, unlike the price, so it’s not worth overpaying “for density”.
Flammability
Polystyrene foam burns only when exposed to open flame. The damping time (self-combustion) is 3 – 4 seconds.
At the same time, when polystyrene foam burns, highly toxic substances are released, causing death from suffocation.
If a fire occurs, you should leave the premises immediately.
Is it possible to use polystyrene foam on concrete walls?
Another important characteristic of any insulation is vapor permeability.
Polystyrene almost does not allow vapor to pass from the room to the street, but for insulating concrete walls this does not matter, since the materials are similar in performance. If the premises of a brick or expanded clay concrete house are humid, properly arranged ventilation solves the problem.
It is undesirable to insulate concrete walls from the inside for permanent housing. In cold weather, the dew point (freezing point) will move closer to inside, the walls will freeze through their entire thickness.
Internal insulation is beneficial for dachas that are not constantly heated. In this case, the building will warm up faster, since the house will become warm before the brick (stone, expanded clay concrete) walls warm up - the heat from the heating devices, like in a thermos, will be retained by the foam plastic.
Which is better - polystyrene foam or polystyrene foam?
Foam plastic - foamed polystyrene. The name expanded polystyrene is commonly understood as extruded polystyrene, produced under the brands PENOPLEX, TECHNOPLEX, URSA.
It has a higher density, the material is durable, and has grooves at the edges for a tight fit of the sheets. There is no crumbling when cutting, which reduces the amount of debris.
The price of extruded polystyrene is significantly higher than polystyrene foam, but the main characteristic of the materials - thermal conductivity - is comparable in terms of performance to PSB-25.
Among the advantages - the material is better resistant to moisture, which is important when insulating basements and ground floors. Installing penoplex on walls has no benefits compared to polystyrene foam.
Do-it-yourself technology for insulating external walls with polystyrene foam
A craftsman familiar with the basics of finishing work can insulate walls.
Let us consider in detail the insulation method called “wet facade”.
Tools
For work you will need hand and power tools:
- level, plumb line, hammer, tape measure, pencil, hacksaw (knife), trowel and spatula;
- bucket for stirring glue and plaster;
- hammer drill or hammer drill with bits or drills for concrete;
- whisk attachments for drills for preparing solutions.
From Supplies acquire:
- glue for polystyrene on a cement or synthetic basis;
- dowels with a rod length 4-5 cm greater than the thickness of the foam;
- mounting foam or adhesive foam;
- foam gun.
Work progress step by step
Wall insulation begins with preparatory work:
- calculating the amount of insulation and its purchase;
You can calculate the area and amount of material by adding up the area of all external walls. When purchasing, add 5% to the calculations for possible errors during fitting and for sheet joints on external corners walls, 6-7 special dowels are purchased for each square meter.
- preparing and checking instruments;
- purchases of consumables;
- installation of scaffolding (if necessary).
The work is carried out in the following sequence:
- The surface of the walls is prepared and cleaned of dust and dirt.
- The voids in the seams (if any) are sealed cement mortar or foam.
- Level the surface with plaster so that unevenness does not exceed 1.5 - 2 cm. This will make it easier to fit the sheets and reduce the amount of expensive glue during further finishing.
- At a level of 50 cm from the ground, a support bar is attached strictly horizontally, if the foam is not placed to the ground, but finishing is provided with another material.
- Using a level and plumb line, markings are made.
- Apply a sheet according to the markings and through it (to avoid mistakes) drill a hole in the wall for the dowel.
- Starting from the central hole, fix the sheet to the wall.
You can attach foam to a flat surface using only dowels. For fastening to poorly plastered walls, a layer of glue is applied to the material plates and pressed against the wall. For reliability, you can fasten the dowels after a day.
When installing the first row, the level is precisely maintained. This will help avoid gaps when installing subsequent slabs.
- The second and subsequent sheets are placed offset (in a checkerboard pattern).
- The seams are sealed with polyurethane foam. Remove excess sealant after complete hardening, usually after 12 hours and up to 24 hours.
Instead of polyurethane foam, it is better to use adhesive foam - it has a lower coefficient of secondary expansion and adheres sheets better.
- Using a special toothed roller or other available means, punctures up to 0.5 - 1 cm deep are made on the surface of the foam for better adhesion to the layer of adhesive plaster.
- A 1-2 mm layer of specialized polystyrene foam adhesive is applied to the foam plastic, which is leveled with a spatula.
- A fiberglass mesh is applied to the glue and “sunk in.” The joints are overlapped, overlapping by 10 cm. The seams between the sheets and the edges of the mesh should not coincide.
- Level the glue with a spatula. By adding portions of glue in the right places, the final leveling of the surface is carried out, working as if using putty.
Finishing
After the composition has dried, prime the surface with products for external use.
The final finishing is carried out with facade paint or bark beetle plaster. The latter option is preferable, as it hides inaccuracies and irregularities, which are especially visible in side lighting.
There are no tricks when it comes to frame insulation. The foam is secured with wide-headed dowels between the frame slats. The remaining voids are filled with polyurethane foam or adhesive foam. Then, without fail, a waterproofing membrane is nailed to the frame. It is convenient to do this with counter-lattice bars, the thickness of which is 1-1.5 cm. After installing the siding or other material, there will be a gap between it and the foam, which will reduce the likelihood of dampening of the materials - the facade will become “ventilated”.
How long will it last
Foam plastic is resistant to moisture and aggressive substances of organic origin, so the service life before replacement is, according to manufacturers, 700 freeze-defrost cycles. This is significantly longer than the service life of the plaster layer, in which, in addition to the composition itself, the polymer mesh is destroyed.
Based on the recommended operating parameters, you can expect the service life of external foam insulation to be from 20 to 40 years. It all depends on quality building materials and careful work carried out.
Insulating the walls of a house with polystyrene foam is one of the available ways to save heat in winter and coolness in summer. A simple installation process that anyone can master makes insulation with foamed polystyrene a popular method that allows significant savings on the purchase of materials and wages for builders.
Useful video
To reduce heating costs, many owners of houses and apartments are thinking about insulation. One of the possible options is insulating the facade with polystyrene foam (PPS or EPS). The work is not the easiest, but you can do it with your own hands. It is important to know the technology. We will talk about it in detail further.
EPS or EPS (foam plastic or extruded polystyrene foam)
Insulating a facade with polystyrene foam begins with deciding the question: what is better to use, polystyrene foam (PPS) or extruded polystyrene foam (EPS). Both materials are made from the same starting material (polystyrene), but they use different technologies. It is hardly worth going into the intricacies of the processes; it is important to know the main differences between these two materials. So, in short:
- Polystyrene foam is softer, absorbs moisture, and insects and rodents like to nest in it. With good characteristics, it has a low cost.
- EPS is harder and denser, practically does not absorb water, insects and rodents do not like it. Its main drawback is high price. In the case of insulating walls from the outside, there is another disadvantage - it is necessary Preliminary processing(you have to scratch the surface), and this is time.
There is another advantage of EPS - usually the slabs are made with a quarter, that is, there will be much fewer direct joints during insulation, and, therefore, fewer cold bridges. The choice is not easy, especially considering that the price difference is significant - 2 times. To make it easier to decide, several positions at EPP and PPP prices are shown in the table.
| Manufacturer/name | Density | Thickness | Sheet sizes | Price |
|---|---|---|---|---|
| PRIMAPLEX 35 (EPS) | 35 kg/m3 | 50 mm | 1200 mm * 600 mm | 4250 - 4400 rub/cub.m |
| PRIMAPLEX 35 (EPS) | 35 kg/m3 | 100 mm | 1200 mm * 600 mm | 4850-5100 rub/cub.m |
| TEPLEX 35 (EPS) | 35 kg/m3 | 50 mm | 1200 mm * 600 mm | 4450-4650 rub/cub.m |
| TEPLEX 35 (EPS) | 35 kg/m3 | 100 mm | 1200 mm * 600 mm | 4450-4650 rub/cub.m |
| URSA XPS N-III (EPS) | 35 kg/m3 | 50 mm | 1250 mm * 600 mm | 4400-4500 rub/cub.m |
| CARBON PROF 300 (EPS) | 35 kg/m3 | 50 mm | 1180 mm * 580 mm | 4500-4650 rub/cub.m |
| CARBON PROF 300 (EPS) | 35 kg/m3 | 100 mm | 1180 mm * 580 mm | 4500-4650 rub/cub.m |
| 17 kg/m3 | 50 mm | 1000 mm * 2000 mm | 2330-2480 rub/cub.m | |
| Penoplast Mosstroy 31 PSBS 25 | 17 kg/m3 | 100 mm | 1000 mm * 2000 mm | 2330-2480 rub/cub.m |
| Foam plastic Mosstroy 31 PSBS 25F (t. 50 mm.) facade | 16.5 kg/m3 | 100 mm | 1000 mm * 2000 mm | 3000-3150 rub/cub.m |
| KNAUF Therm Wall | 25 kg/m3 | 50mm/100mm | 1000 mm * 1200 mm | 2465-2600 rub/cub.m |
| KNAUF Therm Facade Light | 50mm/100mm | 1000 mm * 1200 mm | 2850-2950 rub/cub.m |
Having decided on the type of material, you can begin installation.
Preparatory work
Insulating the facade with foam plastic begins with preparing the walls. Let's immediately say when it is better to start work - in the warm period of time. But the most important indicator is the humidity of the walls. They must be dry. After the rain, it is advisable to wait a week for dry, preferably windy, weather. After that you can start.
Preparation of external walls
Preparation for insulating the facade with polystyrene foam begins with cleaning everything that flakes and falls off. If the walls were covered with paint, it is removed, the lime is cleaned off. If there are swollen areas of plaster or tiles, they will be resurfaced. Only what holds tightly should remain.
Then it’s time to level the walls. It is very good if the insulation boards lie on the wall with their entire surface, without voids. But such walls are the exception rather than the rule, therefore unevenness of about 1 cm per square meter is acceptable. Protrusions and holes that are large in depth/height must be leveled - filled with plaster mortar (pre-primed) or cut off. The smoother the surface, the easier the work will be.
To prime or not
There is no need to prime only those walls; running your hand over them will leave your palm clean. If there are white marks, pieces of plaster, sand, etc., it is better to prime it. This will ensure better contact of the glue with the wall. The operation takes little time, is simple, requires little money, and has great benefits. So if you are doing the insulation of the facade with foam plastic or EPS “for yourself”, it is better to prime it.
Any primer is suitable for facade work. Normal companies are Ceresit, Master, Stolit, Kreisel, Tokan, Ekomix. The primer is diluted or not, depending on the release form and instructions, applied with a brush or spray. Spraying is faster and easier, but using a brush is better.
Preparation of EPPS
If you decide to insulate the walls outside with expanded polystyrene (EPS), its surface must be made not so smooth. Polystyrene foam has a looser structure and preliminary preparation does not need. You need to make scratches on the surface of the EPS, otherwise it will fall off from the glue.
Take a spiked roller, which is used to process drywall, and roll it well in all directions. The second way is to take a brush with metal bristles and make grooves with it. Softer methods don't work. The work is not hard, but it takes a lot of time. This must be done before you begin installing polystyrene foam on the walls. If the insulation is laid in two layers, it is necessary to process the sheets for both layers.
Finishing window sills, slopes, ebb
It is better to install all elements - window sills, slopes and ebb (drip) before installing the insulation on the walls. When installing, you need to remember that you will still have a significant thickness of insulation + finishing. If window sills and slopes have already been installed, they will have to be replaced - they will be too short. In order for everything to look organic and fit easily into the insulating pie, the elements must have the following dimensions:
As you can see, preparatory work Before insulating the facade with polystyrene foam (polystyrene), it also takes time. They are not complicated, but have a significant impact on the overall result.
Technology for installing foam plastic on walls
For a normal result, foam plastic is first glued to the walls, then nailed. Exactly this way and no other way. Gluing begins from the bottom, usually from the left corner. If the house is insulated with polystyrene foam, then the first row is supported by the installed ebb, if the thermal insulation is improved in apartment building, nail the starting bar. Without it, there is a high probability that the foam will creep down.
Materials and tools
To stick polystyrene foam on the walls, you will need two spatulas. One is about 100 mm wide, the second is 180-200 mm. The narrow one is used to pick up glue from the container, and the wide one is used to apply it to the walls. To trim the material, you may also need a saw with a fine-tooth blade. That's all of the tools at this stage. You will also need glue. It requires a special one; the bag should say “for polystyrene boards” or something similar. There are two types of this glue:
- A universal composition for polystyrene and subsequent façade finishing (gluing mesh and leveling layer).
- The composition is only for gluing polystyrene to walls. Other layers require a universal one.
If we approach the issue from an economic point of view, it is more profitable to buy two different compositions - the universal one is significantly more expensive. And with glue you can do a number of operations:
The list of works for which universal glue is required is as follows:
- gluing mesh to corners (and slopes too) and walls;
- applying a leveling layer.
The consumption of both compositions is approximately the same and amounts to 4-6 kg per square meter. The consumption may be less if the walls are initially flat and a smaller layer of glue is required (no need to level the depressions). The consumption for the leveling layer (after gluing the mesh) depends on how smoothly the polystyrene is fixed, whether its corners stick out or not.
For the second stage - fixing the polystyrene to the walls - you will need fungi. These are specially shaped dowels with a large plastic cap and a long stem. Steel or plastic dowel-nails are inserted into the dowels. When insulating a facade with polystyrene, it is better to use plastic ones. They do not conduct cold, are not subject to corrosion, cost less, and a large insulated façade does not create loads.
To install the mushrooms you will need a drill and a hammer. To apply the mesh and leveling layer, you will need an even wider spatula - 300-350 mm or even more. To sand the leveling layer, you will need a plastic grater and sandpaper with a grain of 400-500.
Technique for gluing polystyrene to walls
The glue is mixed with water according to the manufacturer’s recommendations (stir with a drill with an attachment or a mixer). It is more convenient to work when it is a little thicker than it turns out if you follow the recommendations. Therefore, we add a little less water, and then see how convenient it is to work.
If the wall is uneven, apply glue to the wall. This makes it easier to correct unevenness - put more in the recesses and less on the humps. If there is too much of a hump left, a recess can be made in the foam to reduce glue consumption. This trick will not work with EPPS.
Lay the mortar in “cakes” up to 9-10 in area, and also make a roller (not continuous) approximately along the perimeter of the slab, retreating 3-4 cm from the edge. The sizes of the tortillas are not necessarily the same. It is only important to level the surface as much as possible. Having laid out the glue, apply polystyrene foam, press it down, and clap it with your palm (not too hard so as not to crush it). Sausages placed along the edges may come out of the seams or “swim” under other sheets. The fact that they crawl onto other sheets is normal and even good, it will hold on more firmly. But it’s better to pick up the glue that has come out. Then there will be less leveling.
There is a second technique - apply glue to the foam, level it with a comb (notched trowel) and glue it like that. But this method is only suitable for smooth facades without differences.
When laying the second row, the sheets are placed so that the seams are not continuous (offset, such as brickwork). We also make sure that all subsequent rows do not match. Leave the foam glued to the façade for 3 days—that’s about how long it takes for the glue to dry. In the meantime, we glue it on the second section.
A few words about how it is more convenient to glue foam plastic to the facade and what kind of area it is. If a private house is insulated with polystyrene foam, the work area is significant, as is the height. Some of the work can be done from the ground, while some will have to be done from scaffolding. To carry them around less, it is more convenient to carry out work in sections. One section is completed completely - from gluing the foam to the leveling layer, then move on to the next. This order of work has another advantage: less polystyrene remains open (it reacts poorly to ultraviolet light).
We nail polystyrene foam (EPS)
So, after the glue has dried (3 days have passed since it was glued), we take plastic mushrooms (the more expensive ones are hard and clog well). Their length depends on the thickness of the insulation. To it (thickness) you need to add 4-5 cm, by which the fungus should enter the wall. If you have polystyrene with a layer of 50 mm, then the fungi should be no shorter than 9-10 cm.
Fungi should extend 4-5 cm into the wall. There is an inaccuracy in the figure - the mesh is glued on top of the fungus
One slab requires 5-6 mushrooms. In selected places, holes are drilled (10 mm drill) 2-3 cm deeper than the length of the fungus stalk. If you make the holes shorter, they become clogged with material dust and are not inserted completely. The location of the fungi is one in the center of the slab and several at the joints. This position allows you to nail the foam and level the wall at the same time (pull the coal into the desired position).
IN drilled hole inserted, then driven in with a hammer, fungus. Its cap should lie tightly on the insulation. If it doesn’t lie, take it out and deepen the hole. Sometimes after a certain number of installed fungi they stop clogging. This means that the drill has become worn down - it has become smaller in diameter - and it’s time to change it.
The fungi are hammered in so that the cap is slightly recessed in the foam - it goes away by about 1 mm. Then the glue consumption for the leveling layer will be less. It’s easy to hammer in with polystyrene foam, but more difficult with expanded polystyrene (EPS).
If there are two layers of insulation
If the required insulation thickness is more than 50 mm, but less than 100 mm, two layers are laid. In this case, one layer is glued, as described above, the sheets of the second are positioned so that they do not coincide with the joints of the first. When gluing the second layer, it is more convenient to apply the glue to the sheet rather than to the wall. The joints of the first one do not need to be rubbed or foamed - they will overlap.
If you have time, it is advisable to wait until the first one dries before applying the second coat. If this is not possible, you can glue a second one at once, but to a height of no more than 2 m, otherwise the sheets may move.
We begin nailing the foam with fungi after the glue has dried (the same 3 days). Just don’t make a mistake when calculating the length of the fungus - the total thickness of the insulation + 1 cm for glue + 4-5 cm for the wall. The depth of the hole is another 2-3 cm larger, the diameter is the same 10 mm. When the foam is nailed to the facade, you can move on.
Sealing joints and fungi
First, we level the area of the facade covered with foam plastic. It often turns out that the edges of the foam stick out somewhere. They can be cut with a stationery (wallpaper) knife. There are also special graters for foam plastic. They are convenient for leveling the surface. You can also try to do this with EPS, but only with a knife, and it doesn’t cut well. The work takes a lot of time, but it’s worth spending time on it - it will greatly reduce the consumption of expensive compounds for subsequent layers of finishing.
Then, to prevent cold air from getting between the slabs, the seams are rubbed. Using a spatula, use the same compound that was used to glue the foam onto the façade and fill the seams. If there are seams larger than 3 mm, we put a narrow strip of insulation in them, then seal them with glue. You can fill the seam with foam. We leave it for 4-5 hours, then cut off the excess with a knife and rub it with glue on top. The caps of the fungi are recessed; we cover them too, leveling them with the main surface.
When grouting seams and caps, we try to make the surface smooth - the glue should not protrude. If you looked somewhere, after drying, take a grater, attach sandpaper (400-500 grain) and level it. You just need to wait for it to dry completely - once it gets into wet glue, the sandpaper instantly becomes clogged, you just need to change it (the mesh is not suitable for this work).
Reinforcement and plastering of foam plastic
Sometimes the insulation of a facade with foam plastic needs to be extended over two seasons - left to overwinter at some stage. Without harm to materials, it can be left only after applying a leveling layer. Simply attached polystyrene foam (EPS) cannot be left. It is recommended to keep it even packed in packs indoors and not outside. So you can only stop after plastering.
Sticker of reinforcing mesh on corners
The mesh is used as a façade mesh for exterior work (the inner mesh will simply fall apart from the glue). Density 140-160 g/sq. m. First, glue the corners. All corners are reinforced - both external and internal, and slopes. Important! From now on, you need to use a universal composition, and not the one on which the foam was glued. The glue is diluted a little thinner than indicated in the instructions - it should stick well to the spatula, but be easily pressed through the mesh.
Can be used for reinforcement finished corner with a mesh, you can cut strips from a roll (30 cm wide) and glue them. It’s easier to work with a ready-made corner, cheaper - with a piece of mesh. If you make it from a roll, cut strips across the roll, you get pieces a meter long. Fold them in half lengthwise and press the fold well with a spatula. You need to fold it so that the edges of the mesh are wrapped inward (it was in a roll). If it turns out the other way around, they will stick out from the layer of glue and it will be difficult to work.
Either way the work is almost the same. A strip of mortar 6-7 cm wide and 2-3 mm thick is applied to the corner on both sides. If you are gluing not a finished corner, but bent strips of mesh, then the length of the area filled with mortar should be 5-7 cm shorter than the cut piece (93-95 cm).
A corner or piece of bent mesh is placed on top. Running a spatula over the mesh, lightly press it into the glue. Herringbone movements - from top to bottom and to the side.
About half of the mesh on the sides remains without glue. This is normal - it will be easier to join it with foam reinforcement in the plane of the wall. Also, without glue, a strip remains at the top if you glue from pieces. When gluing the next piece above, apply glue directly to this “empty” mesh and cover it with the next piece on top. This way the joint is the same thickness as the entire corner.
When forming an angle, we try to make it even. If you can’t do it with a regular spatula, you can use a corner one (pictured above). It won't be difficult - just move from top to bottom with one click.
Foam reinforcement on walls
Polystyrene foam and EPS are reinforced by applying a layer plastic mesh, which is pressed into the adhesive composition (universal). The procedure is as follows:
The glued mesh is left to dry. It should take at least half a day, or better yet, a day. Then take a grater with sandpaper and smooth out all the unevenness.
Foam plastic plaster (applying a leveling layer)
The technique of applying plaster to polystyrene foam is no different from the standard one (). The thickness of the leveling layer is determined based on the results of previous work. If the previous layer was applied evenly, the leveling layer can be very thin - a few millimeters.
There is only one peculiarity - the mixture should be slightly liquid. A little thinner than when applying the mesh. This consistency makes it easier to level.
The applied leveling layer is left to dry. The time depends on the temperature and thickness of the layer. Wait until it dries completely, otherwise the sandpaper will clog. By the way, at this stage it is better to use it already worn - the surface will be smoother. The new one leaves some decent scratches. This is critical if you plan to simply paint the facade in the future, but you can work with a new one before applying decorative plaster.
This completes the insulation of the facade with polystyrene foam. Next - finishing work. What they will be like is up to you to choose.
The video demonstrates all the stages. There is only one mistake: when gluing the mesh, it rolls out onto the laid layer of glue, and not onto the dry wall. With such technology as in the video, there is a high probability that all the finishing will fall along with the mesh.
