When choosing which insulation to protect the building from the cold, they often stop on polystyrene foam. This material has a low cost and does not require installation experience. But, using polystyrene foam for insulation, it is required to comply with several requirements. They are due to the performance of the material.
Application area
When insulating a house from the inside, it is necessary to increase the thermal insulation of the following structures:
- in the construction of the basement floor on the ground, if the underground floor is heated;
- in the pie of the floor of the first floor with the device of a cold basement or underground;
- exterior walls;
- overlapping above the last floor with a cold attic;
- coating when installing a warm attic;
- mansard roof.
Of all these parts, polystyrene foam for home insulation is best used in wall construction. In the floors, polystyrene should be used only in conjunction with lags, which will bear the main load from the floor, furniture, etc. The thing is that the density of the polystyrene foam does not allow it to withstand high compressive loads.
Overlapping with foam without lag can be used for technical purposes - attic flooring, etc. Therefore, if you want to qualitatively insulate the floor under the screed - the best option for insulation is extruded polystyrene foam. The insulation on top should cover a layer of cement-sand screed 50 mm thick with additional reinforcement. For reinforcement, a mesh of reinforcement with a diameter of 3-4 mm is used.
Another area of application of foam is the manufacture of fixed formwork for concreting. Such a heater is used in the construction of strip foundations. Allows you to reduce the number of stages of work on pouring a monolith at home and at the same time perform thermal insulation of the structure. Without fail, reliable waterproofing should be provided on top of the polystyrene foam.
Types of polystyrene for home insulation
To understand what polystyrene foam is needed for specific types of work, it is worth carefully studying the varieties of material. The classification of heat insulators for the walls and floor of a house is carried out according to the following criteria:
- raw materials for manufacturing;
- density;
- sizes.
Depending on the raw materials used, such types of foam are distinguished as polyurethane, polyvinyl chloride (PVC) and polyethylene. The first has high elasticity and is a foam rubber, actively used in the furniture industry. In construction, polyurethane foam is made from such a foam.
Polyfoam polyethylene is produced in the form of sheets and is used to pack fragile things. The usual building polystyrene is PVC. Expanded polystyrene of this type is suitable as a heater of the house inside and out.
The density of the foam is an important indicator. The field of use of the material depends on it (can it be used in the construction of walls, floors, foundations, etc.). Before buying a foam insulation for a home, it is better to familiarize yourself with what it happens depending on the feature under consideration:
- PSB 50 is a high density material. In construction, it is not common because of the desire of customers to reduce financial costs. Such material is suitable as insulation from the outside and from the inside. Such material is allowed to be laid as part of the floor of rooms with a constant stay of people, the location of furniture and equipment.
- PSB 35 is suitable for insulating the walls of a house from the outside and from the inside. This type of insulation can also be placed in the pie of the attic floor, provided that there is a strong concrete screed. Density of expanded polystyrene 35 is the most common.
- PSB 25. The density of the material allows it to be used as wall insulation from the premises. When laying, it is necessary to provide a gap between the heat insulator and the finishing material. For flooring and external insulation, it is strongly not recommended.
- PSB 15 - the minimum density used in construction. This type is best suited for thermal insulation of temporary structures (for example, change houses), containers and wagons.
Sizes of foam sheets are typical. If necessary, it is easy to cut the desired shape from the material. Dimensions are prescribed depending on the area of the insulated surface, its length and height.
The following sizes are sold on the construction market:
- 2000x1000 mm.
- 1000x1000 mm;
- 1000x500 mm.
The most common sizes are 1000x1000 mm. Such sheets will not cause problems during transportation, at the same time they have a sufficiently large area and can increase the speed of work. The standard size of 1200x600 mm is also very popular - it perfectly suits the pitch of the racks or crates with external insulation.
Thickness calculation
Before buying a material, it is necessary not only to choose its strength and dimensions, but also to calculate the required thickness of the insulation for walls or other structures. When designing a building, specialists perform special heat engineering calculations manually or using programs, the field of which is assigned to the dimensions of the heat insulator.
The thickness for a private building can be selected without making a calculation. But it is necessary to take into account the climatic features of the terrain and the operating conditions of the facility. In the vast majority of cases, the following sizes can be recommended:
- wall insulation thickness - 100 mm;
- thickness for attic flooring - 150 mm;
- thickness for the floor of the 1st floor and the roof - 200 mm.
But in any case, it is better to assign dimensions accurately. It is possible to calculate the required insulation value using fairly simple programs. For example, the calculation can be done in the Teremok program. It is available on the Internet in the public domain. There are two versions: online and a PC application.
To perform the calculation in the program, you need to know the composition of the building envelope and the thermal conductivity of the materials used. Some types are in the program database, but it is better to check the thermal conductivity of the manufacturer of a product. Calculating a heat insulator using this application is quite simple.
Insulation technology
Once it is decided what material is required to carry out the work, It is important to familiarize yourself with the nuances of the technology of work. When attaching, it is necessary to take into account such features of thermal insulation as:
- low strength;
- destruction under the influence of moisture and cold (high-quality waterproofing and vapor barrier will be required);
- instability to fire;
- low vapor permeability, creating a greenhouse effect in the house (requires forced ventilation).
The material can be attached from the side of cold air or from the inside. Foam insulation from the outside will be more competent. Insulation of the walls with foam from the inside can only be done if there is justification (there is no way to disassemble the decoration of the house, the insulation of one apartment in an apartment building).
We also recommend that you familiarize yourself with the instructions for floor insulation with foam. Insulation of ceilings with this material also has its own nuances. To provide reliable protection against cold, it is better to place a heat insulator on the side of cold air.
Fastening to the wall is carried out on glue, and after the solution dries, the material is additionally fixed with dowels-fungi. Before proceeding with fixing with dowels, it is better to wait about 3 days. If the heat engineering calculation was performed correctly, and the technology was not violated during installation, the foam will be durable and reliable.