Already in the middle of the last century, foam was actively used in construction. In recent years, its popularity among home masters and professionals has increased significantly. This material is actively used today as a heater for homes and buildings for various purposes.
It stores heat well, is easy and convenient to install, and also does not decompose under the influence of microorganisms. Among the advantages of the foam can be identified environmental friendliness, versatility, cost savings on repairs and a long service life.
The need for external foam insulation
Covering the house with polystyrene can significantly reduce heat loss. For heating in winter you have to spend not so much money. Yes, and in the summer, the rooms become much cooler and more comfortable. With temperature fluctuations outside the window during the off-season, the microclimate in the house will be better for living. For several reasons, external insulation is the most reasonable solution.
If we compare this technology with that which provides for the installation of thermal insulation from the inside, it can be noted that the internal volume of the rooms is not reduced. With external insulation , the dew point will not be inside the wall or house. The problem of freezing walls will be completely forgotten. The material at the base of the building will not get wet and will not collapse.
The sheathing of the house with polystyrene is also justified for the reason that the main walls will have a thermal inertia, which stabilizes the temperature inside the premises. During night frosts, warm walls will not allow air to cool quickly in rooms.
Features of the choice of material
Before covering the house with polystyrene foam, it is necessary to select the material. It is better to choose a canvas labeled C-25, the density of which is mentioned in the title. Many consumers are wondering what it affects. The lower this indicator, the better the heat-insulating properties. To confirm, it is enough to recall the school physics course, which speaks of air - the best heat insulator.
The insulation with the mentioned density has closed cells filled with oxygen, which will prevent convection and reflect infrared radiation. But this belief should not be applied to foam with a density of 15 kg / m 3 . This also applies to mineral wool. These heaters are less dense, but not able to provide sufficient rigidity. It will be difficult to plaster the insulated facade without damaging the insulation layer, and in the future it will be easy to wash the walls.
Insulation Instructions: Wall Preparation
Sheathing the house with foam is carried out in several stages. Before starting work, the walls are aligned. Cavities and protrusions are undesirable. If the façade is not level, then soft material may be broken. The best solution for preparing walls will be the application of plaster on them. The size of the protrusions and depressions should not be more than 2 cm.
If the surface is flat, then it is necessary to inspect the texture of the wall, it must be rough to ensure adhesion to the glue. If the facade is painted with paint with zero vapor permeability, then the layer must be cleaned, and then coated with a primer.
If you decide to carry out the sheathing of the house with foam yourself, then at the stage of preparation for the facade you need to hand. If a chalky trace remains on the palm of your hand, then the surface must be primed. When in contact with a wall its material crumbles, albeit slightly, the base should be brushed and primed.
In any condition of the wall, this composition must be applied. It is better if the mixture has a good penetration. This will strengthen the material, which is especially important if it is necessary to glue the adhesive to the wall.
Styrofoam Preparation
The sheathing of the walls with foam from the outside requires the preparation of a heater. This step relates to extruded polystyrene foam called foam polystyrene. The technology differs from the sequence for polystyrene only in that in this case it is necessary to have a smooth surface that needs to be roughened. The sheets must be pierced with a needle roller. Sometimes they are notched with a stationery knife.
Profile Installation
In order to support the insulation system from below, it is necessary to fix the profile in the form of a stand on the facade, which is also called the starting bar. The width of this element should be equal to the thickness of the foam. Before starting work on the wall, marking is necessary. Use for this you need a building level or chalk rope.
On the wall, a horizontal line is beaten off, along which the starting bar will be aligned. The profile is fixed by dowels with a washer; they are driven in or screwed in every 400 mm. At the corners of the house, the starting strips are installed with corner joints made of plastic. These parts will play the role of compensators for temperature differences, they are necessary to dampen linear expansion of the material.
Insulation Installation
Covering the facade with foam at the next stage provides for the fastening of paintings. It is optimal to use dowel umbrellas or glue for this. In the lower part of the wall horizontally, it is necessary to fix the starting profile, which will prevent the foam from slipping.
Next, glue is applied to the facade. The cultivated area should be equal to the perimeter of the sheet. On the back of the insulation, it is also necessary to apply an adhesive composition. The thickness of the cakes will allow to level the recesses. The canvas is pressed against the wall, and then you can proceed to fasten the next product. Horizontal sheets are glued with offset vertical joints. Four corners should not converge in one place.
It is necessary to install polystyrene from the bottom of the wall. The glue-coated board adheres well to the surface and holds for several seconds. The second canvas is pressed and trimmed in level.
Throughout the work, the wall should be checked for flatness using the building level. The standard joints between the panels are usually 3 mm. Excess glue protruding from the seams is carefully removed.
Mechanical sheet fastening
Once the facade cladding with foam with your own hands with glue has been completed, you must leave the walls for 3 days. The purpose of this exposure is that the glue should dry well. Then the sheets are fixed with dowels in the form of umbrellas. There should be 5 fasteners per square meter. Their length should be such that they enter the main wall 5 cm or more.
Dowels are also called fungi, they can be located in the center and along the edges. In the latter case, you need to make a small indent. An alternative arrangement of fasteners are the docking points of adjacent paintings.
Three important rules to follow
When reading the instructions for covering the house with polystyrene foam, you must follow three important rules. One of them says: if between the sheets cracks formed more than 5 mm, then they should be filled with foam.
The second rule is that visible bumps must be removed with a foam grater.
The third rule is expressed in the fact that when fixing the insulation in two layers, the second is installed with overlap of the seams. In this case, the seams of the first layer are not filled with foam.
Reinforcing mesh installation
A glass mesh acts as the basis for applying plaster. It is necessary to choose it from the calculation of density, which reaches 160 g / m 2 . Fastening should be carried out on glue, which is prepared on a cement basis. It is necessary to distribute the solution in sections whose dimensions will be 1x1 m.
A reinforcing mesh is heated in the glue layer, a wide spatula must be used for this. From above it is covered with another layer of solution. The surface should be as even as possible. In this case, some subtleties should be observed.
Horizontal strips of reinforcing material should have an overlap of 10 cm. The corners of the facade are reinforced with a plastic perforated corner, as an alternative solution, a galvanized corner can be used.
Warming of a wooden house
Having looked at the photo of the foam for lining, you will understand that after carrying out insulation work, it will be necessary to protect the walls and make them more aesthetically attractive. In the case of wooden houses, the installation technology of foam plastic looks a little different. The technique involves the use of a frame structure. Installation is carried out between the elements of the crate. You can use glue as fasteners, but sometimes the craftsmen dispense with ordinary dowels.
The surface must be prepared by setting the gap and covering the material with protective substances. Next, vapor barrier and frame elements are installed. The insulation is placed on the glue; in addition, after it dries, it is possible to fix it on the dowels.
At the final stage, a second layer of waterproofing should be laid, only after you can deal with the front finish. The sheathing of a wooden house with foam requires the installation of a frame for the reason that the described insulation has poor vapor and moisture permeability. As a result of this, no air enters the room.
Finally
Exterior insulation of the house with polystyrene is very effective. However, to achieve a positive result, it is necessary to observe all the rules of the technology. One of them is to ensure the rigidity of the layer at the corners. This applies to interior and exterior corners. Plates in these places are laid by the method of gear connection along the height of the building. On slopes and other difficult sections of the facade, you can use additional fasteners.