An attic is a warm living room that needs protection from the cold outside air. Doing warming the attic of a private house from the inside with mineral wool is an feasible task. Before this, it is important to study the characteristics of the material and the features of working with it.
Types of mineral wool
The building materials market offers a huge number of thermal insulation options. Mineral wool insulation can be carried out using the following types:
- stone (basalt);
- glass;
- slag.
Stone wool is available in slabs. This is the most common material for attic insulation, since it is easiest to lay. Glass wool is sold in rolls of mats. This type of material is less convenient when performing insulation work. Slag for a private house is rarely used.
Why is it better to use hard slabs of mineral wool? This is due to the convenience and adaptability of the installation. Do-it-yourself warming of the attic from the inside is easier to perform with plates that hold their shape well and are able to stay between the rafters due to friction. It is more difficult to fix mats on an inclined surface.
Advantages and disadvantages of mineral wool
Insulation of the attic from the inside using mineral wool is characterized by the following positive characteristics:
- high degree of protection against cold;
- incombustibility;
- good sound insulation (especially true when using metal as a roofing);
- the absence of deformation during heating and cooling, which is especially true for roofing cake materials, which are subjected to strong heating in the summer and cooling in the winter;
- resistance to rot, fungus, mold and damage by other microorganisms;
- resistance to certain chemicals;
- profitability;
- availability;
- manufacturability.
Among the shortcomings can be identified the most important - the ability to absorb water. When saturated with water, the material loses its heat engineering properties. Therefore, together with the insulation of the attic with your own hands from the inside, you need to provide measures to protect the insulation from moisture and to remove it from the surface. Another feature of the material is the need for safety precautions when working with it. In this regard, it is much easier to work with polystyrene foam or polystyrene. Safety precautions when using mineral wool is to prevent particles of insulation from entering the skin of workers or the lungs. To do this, warming the attic with your own hands with mineral wool should be done with gloves, glasses, a mask and special clothes that do not leave exposed parts of the body.
Preparatory stage
To ensure the necessary degree of protection against cold, the thickness of the insulation must be selected correctly. In general, for mineral wool, the thickness is 150-200 mm, depending on the climatic region. To calculate the insulation of the attic from the inside, you can perform calculations in two ways.
Manual calculation
In this case, it will be necessary to study in detail the JV Thermal Protection of Buildings, which contains formulas and data for the calculation. The method is time-consuming, to understand the intricacies of the calculation technology in order to perform it once, is rather irrational.
Calculation using the program
In the public domain there is a program "Teremok". It is developed in two versions: an online version and a PC application. For a one-time calculation, it is easier to use the online service. Two operating modes are offered. One of them selects the required thickness of the insulation when known for all other layers, and the second checks the compliance of the selected or existing design with regulatory documents.
To perform the calculations you need to know the thermal conductivity of all materials.
When the attic is insulated with mineral wool from the inside, the following structural layers are taken into account: ceiling lining, lower lathing (if it is continuous), insulation. Everything that is located above the ventilated layer between the surface of the heat insulator and the roofing is not taken into account.
Extra tip
When doing the work yourself, you can take the thickness of the insulation approximately based on the recommendations for a certain type of terrain, but this can lead to the following losses:
- thermal with insufficient thickness (consequently high heating costs);
- financial (with excess insulation thickness).
It is best when the thickness is selected specifically for the case in question. This will avoid problems and errors.
Work order
To perform the insulation of the attic from the inside with your own hands, you must adhere to the following recommendations:
- First check the evenness of the rafters. This can be done using the rule - a metal rail, which is applied to the beams.
- Measure the distance between the rafters. For the convenience of working with mineral wool at the stage of designing the roof, you should take the step of the rafters so that the distance in the light between them is 580 or 1180 mm. This will allow the use of slabs with a standard width of 600 mm without cutting. It will be easier to work with a step of 580 mm, since here you need to lay only one plate in width, therefore, its fixing is simplified. A margin of 20 mm is needed so that the plates are held during installation due to friction forces without additional fasteners. In addition, the installation with a spacer avoids the occurrence of gaps and gaps between the beams and insulation plates.
- Insulation work begins only after waterproofing and roofing are already installed. This is necessary to protect the material.
- If the distance between the rafters does not correspond to the above values, then the cutting of the thermal insulation plates is performed. In this case, the above margin of 20 mm is provided (the width of the thermal insulation element should be greater than the distance between the rafters in the light).
- In order to install mineral wool in the design position, it is slightly compressed and mounted between the load-bearing roof structures. At the same time, the absence of wrinkling and wrinkles on the surface of the insulation is controlled. It is important to control the quality of the fit of the material in the places where dormers are installed. To do this, you need to cut some non-standard insulation elements and install them on the frame in the same way as for the entire plane of the roof.
- Insulation of the attic from the inside includes not only the insulation of the roof, but also the walls (in the event that on the previous floors it is not performed outside). To insulate the gables or external walls on which the slopes rest, you need to build a frame. The distance between the racks is based on the recommendations in paragraph 2. It is important to take into account that the requirements for heating equipment for walls and roofs are different, therefore, two separate thickness calculations will be required (using the program will not greatly increase the time costs).
- After installing the slabs, attic insulation involves the removal of all paths for the penetration of cold. To do this, use sealant or polyurethane foam and fill the joints between the extreme rafters and the wall and other weaknesses.
- To prevent the heater from getting wet from steam from a warm room, a vapor barrier film is mounted. Most often, polyethylene is used as it, but the use of vapor barrier membranes will be a more modern solution. The material is smoothed and attached to the rafters on a building stapler. the pitch of the staples is 15-20 cm. The film is mounted with an overlap of 10-15 cm. After fixing, the joints of the strips of the film are glued with tape, which will provide additional reliability of the insulation protection. After the vapor barrier film, the lower crate is fixed, which will hold the mineral wool in the design position and will become the basis for the construction of the ceiling.
The attic insulation is now over. It remains only to cover the ceiling. The most commonly used installation of drywall sheets on a metal profile. The profile is fixed perpendicular to the rafter legs on the self-tapping screws with a step of not more than 50 cm. Next, sheathing sheets are attached to it. After fixing the drywall base, you can begin to finish the ceiling.
Such work can be done alone, but it is better if there are two builders. This will increase the accuracy of the work, since one person can hold the element and control the compliance of its position with the design, and the other carry out fastening. Warming the attic with mineral wool will not take a lot of time and will not cause special difficulties in the process, if you follow the recommendations.