How and how to properly insulate a mansard roof with your own hands

Private property owners have to deal with the shortage of living space and energy savings. These questions are especially relevant for the owners of summer cottages, when they often have to receive many guests and relatives. Competent insulation of the attic will make it comfortable for living at any time of the year with minimal heating or cooling costs. In order to avoid annoying mistakes during construction, you need to familiarize yourself with the properties of the commercially available thermal insulation and the technology for its installation. With the correct organization of work, it can be done on your own, saving on the services of professionals.

The choice of insulation for the attic

Insulation for the attic should be chosen based on its purpose, size, configuration and climatic conditions. You can get a scientifically substantiated certificate about which insulation is better for the attic roof, you can in SNiP 23-02-2003.

The construction market is saturated with materials of various shapes, composition, cost and technical characteristics intended for thermal insulation of residential premises. To make the best decision on their choice, you should consult with friends and professional builders, study the properties, pros and cons of the heaters on sale. Experienced builders recommend carrying out the insulation of the attic roof in a complex manner, using different substances for decoration outside and inside, taking into account their properties, advantages and disadvantages.

Minvata

Minvata is the most popular and demanded material in construction due to its high performance. It is made of broken glass, steel-making slag and natural stone. Finished products are spatially interwoven fibers of matter in the form of mats and rolls 100-400 mm thick. Since the substance has sufficient strength and elasticity, its main volumetric component is air, which practically does not conduct heat and cold.

Mineral wool has the following advantages:

• excellent sound insulation properties;
• low thermal conductivity;
• ecological cleanliness;
• ease of installation;
• elasticity, due to which there are no gaps in the masonry;
• medium degree of hygroscopicity;
• fire resistance, the ability to create a reliable barrier to flame;
• almost infinite service life.

Mineral wool is not ideal for builders, as it also has a number of disadvantages. Quality products from trusted manufacturers are quite expensive. During styling, many tiny volatile fibers are released. When insulating the attic floor with mineral wool, it is necessary to use means to protect the skin of the hands, face, eyes and breathing. In addition, moisture absorption leads to a decrease in insulating qualities.

Styrofoam

When deciding which insulation for the attic roof is better, many owners of private houses opt for foam. This is a justified preference, since PP has numerous advantages that affect the quality of the building's thermal insulation:

• low density;
• convenient standard size 100x100 cm;
• insignificant thermal conductivity;
• affordable cost;
• ease of processing;
• long service life;
• waterproofness.

The disadvantage of the insulation is the flammability and toxicity of gases released during this process. In addition, the substance is very fragile; care must be taken when transporting and storing it. Since polystyrene is environmentally friendly, insects and rodents like to settle in it. A good, but more expensive analogue is penoplex, which is flexible, resilient and has a longer service life. The plates have locks on the sides, which ensures a tight and durable connection.

Polyurethane foam

Polyurethane foam is a product of modern technology and has high performance characteristics. It belongs to the category of sprayable materials obtained by mixing two inert ingredients. It is applied using industrial equipment or disposable spray cans ("polyurethane foam"), which are sold at any hardware store. A liquid substance comes out of the atomizer, which penetrates into the smallest cavities. In the process of foaming, it increases in volume and hardens, acquiring a dense consistency.

Advantages of PPU:

• the lowest thermal conductivity among analogs;
• environmental Safety;
• no need for external finishing;
• long service life;
• waterproofness;
• lack of hygroscopicity;
• high degree of adhesion to any substances.

The main disadvantage is the high cost of polyurethane foam. In addition, in remote regions there may not be specialists of such a profile, and the use of spray cans is a very costly event.

Ecowool

Ecowool is often used when you need to qualitatively insulate the attic for winter living, since the material has excellent insulating properties:

• the substance is completely natural and environmentally friendly;
• porosity, providing low thermal conductivity;
• light weight, even a thick layer does not exert additional load on the supporting structures;
• the presence of a natural antiseptic (borax) in the composition, due to which the occurrence of mold and mildew is excluded;
• filling of all voids, which contributes to the absence of cold bridges after application;
• preservation of the original volume.

When deciding to insulate the attic with ecowool, it must be borne in mind that it is flammable, in the absence of high-quality sealing, it absorbs moisture and loses its quality. In addition, the substance of natural origin attracts insects and rodents, which like to arrange their nests in it and exist in them for decades.

Preparatory stage

Insulation of the attic roof is a responsible event that requires careful preparation. You need to pay attention to the choice of tools and materials, as well as safety.

1. Check the condition of the rafters, floorboards and other structural elements. Reinforce them if necessary.
2. Make ventilation openings and lay ducts for air exhaust from the room.
3. Remove from the attic all non-repair items, debris, sawdust, clean the surfaces from dust.
4. Install special channels for communications, so that after the attic is insulated from the inside, there is free access to them for inspection or replacement.
5. Treat the wooden parts of the roof frame with an antiseptic, hydrophobic agent and fire retardant.

It is necessary to waterproof the surfaces to prevent water from entering the attic from the outside and to ensure that vapors are evacuated from the inside.A super-diffuse membrane that fits on the outside of the frame works best. From the inside, it is sheathed with a vapor barrier material based on fabric or foil.

The fastening of the canvases should be carried out with brackets made of stainless steel or copper. The strips should be applied with an overlap of 15-20 cm, and the joints should be sealed with aluminum tape. The film must be fastened with a sagging of 10-15 mm, so that when the temperature drops, the vapor barrier does not break from strong tension during the shrinkage process.

Step-by-step instructions for warming

Experts in the field of construction recommend to carry out the insulation of the attic floor in a comprehensive manner, on both sides, using a supporting frame to place the thermal insulation. This approach will save usable space under the roof of the second level of the building. Before starting work, you need to draw up a stacking scheme, calculate the material requirements. You need to take it with a 10-15% margin to cover errors and damage during transportation.

It is advisable to start insulating the structure from the outside. This is justified by the fact that after laying the material, a roof will be mounted on top of it, which will protect the structure from dampness, mechanical damage, ultraviolet radiation and precipitation.

Step-by-step instructions for performing this stage of work:

1. Placement of insulation between the rafters. Mineral wool or foam is used here. The mats and rolls are cut so that they forcefully enter the openings and are held firmly therein. For this, the width of the blocks is made 2-3 cm larger than the openings. The polystyrene is inserted end-to-end, the cracks are filled with polyurethane foam, the excess is cut off.

   

2. Attaching a membrane film, it is needed to remove moisture that penetrates the walls from the interior.
3. Creation of a base for finishing. If a soft finish is chosen, the frame is sheathed with plywood, planks or OSB. For rigid materials, a crate is made with an appropriate step. For this, it is better to use a moisture-resistant metal profile.

The final step is the installation of the roof covering. The correct solution is to use materials with low thermal conductivity. Ceramic tiles, facade panels and plastic hollow panels are well suited for a gable roof.

Insulating the roof from the inside, if it is already covered, is not particularly difficult, since you have to work in a comfortable and safe environment. In most cases, materials of small thickness are used, which perform the functions of finishing and protection from external noise.

It is necessary to equip thermal insulation from the inside in the following sequence:

1. Bring insulation to the attic. Take it out of the packaging and let it rest for a day so that it meets the installation conditions.
2. Measure and cut the workpieces to the desired size. Mark them so as not to be confused when laying. Make similar markings on surfaces.
3. Place the insulation elements on the lower level. Subsequently, the finishing will be a support for wall insulation. It is necessary to choose the material for the floor in advance in order to make a crate of the proper shape under it. It must correspond to the climatic conditions in which the structure will be used. In addition, you need to take into account the purpose of the attic. Safe fillers should be chosen for living quarters.
4. Install the vapor barrier. It is fastened with staples using a stapler. The overlaid edges are securely closed with construction tape.
5. Install a rough or final flooring. For carpet, laminate or linoleum, shields are laid. Sanded boards with side locks can be placed directly on the frame.

Then each wall and ceiling is equipped, which are often adjacent elements in the structure.This is done in the following sequence:

1. Equip a frame for insulation. For this, boards or steel profiles are used. The supporting structures are treated against corrosion.
2. Filling cells with thermal insulation. This should be done in accordance with the instructions for use for each material used.
3. Sealing the insulation with a vapor barrier sheet.
4. Base application for a soft finish such as wallpaper, leather or carpet. This is not necessary for hard floors. Slats and panels can be directly attached to the frame.

The material for interior decoration must be safe in terms of fire and environmental protection.

Required insulation thickness

The required thickness of thermal insulation can be calculated mathematically by multiplying the thermal conductivity of the material by the regional indicator, which is established by analytical calculations. These values ​​are established by analyzing the average annual temperature over the past 50 years.

For the central part of Russia, the following indicators of the thickness of materials used in construction are optimal:

• mineral wool - 15 cm;
• foam - 10 cm;
• polyurethane foam - 8 cm;
• ecowool - 15 cm;
• expanded clay - 25 cm;
• expanded polystyrene - 10 cm;
• a mixture of clay and sawdust - 35 cm

The numbers are averages and do not apply to abnormal temperatures.

Common mistakes

Most often, beginner masters make the following mistakes:

• ignoring the installation of a vapor barrier, which leads to the formation of dampness in the ceilings;
• incorrect installation of the drainage system;
• installation of a thin layer of insulation, which leads to overheating and freezing of the attic;
• leaving open the joints of waterproofing sheets;
• excessive tension of the vapor-permeable film, which leads to its rupture during cooling.

To avoid mistakes, you need to follow the instructions of the material manufacturers, the recommendations of the professionals and the construction plan.