How to properly insulate an attic in a private house with a cold roof

A large amount of heat escapes through an uninsulated attic, for which money is paid. As a result, the indoor temperature does not rise and utility costs rise. The only way out is to insulate the cold attic with inexpensive building materials. If you have time and extra money, you can insulate the roof, but this is not necessary, because it is enough to insulate the ceiling from the attic side and all the heat will remain in the room.

What is the insulation of the attic for?

The floor area in a private house is equal to the area of ​​the ceiling through which most of the heat escapes. In a cold living space, more moisture forms, so the likelihood of fungus formation increases, which leads to respiratory diseases in the future. The most unpleasant sensations arise in the bathroom, the floor and walls in which do not have time to dry out, discomfort is created, in addition, the cold in the bathroom contributes to colds when there is a sharp change in temperature. Children in such conditions are more likely to get sick.

Most of the insulating materials drain water well, therefore, when insulating, condensation will not accumulate on the walls. Warm air dries up excess moisture, while walls and floors are warmed up.

If you insulate the roof slopes and pediment, moisture will not form in the attic and the smell of mold will not be heard. This is more difficult work, but doable since the materials are light in weight.

It is best to carry out work on the insulation of the attic with your own hands, so as not to spend extra money on wages. It is necessary to choose a heater according to its technical characteristics, calculate its quantity and install it according to the available technologies. The whole work can take 1 day.

Materials for thermal insulation

On the insulation market, you can find both natural and artificial materials. Their difference lies in cost, efficiency, service life, coefficient of thermal conductivity.

Mineral wool

Mineral wool or its varieties - glass wool, basalt insulation, slag wool - are distinguished by an increased coefficient of thermal conductivity due to the structure of randomly located fibers. Cold air in winter does not penetrate into the room from the outside, and in summer it is cool in it, since cotton wool does not allow air currents cooled by air conditioning to pass through.

Of all the varieties of mineral wool, it is recommended to choose basalt insulation for the following reasons:

• The material does not crumble and does not cause an allergic reaction. You can work with stone wool without protective equipment.
• Service life is about 50 years.
• Volcanic rock mineral wool comes in different densities - you can choose the appropriate option for any region, including the coldest.
• Basalt wool is a light material, so one person can handle it.
• Basalt mineral wool does not burn. It can be melted with very high temperatures, so the attic will be safe.

An additional advantage of basalt insulation is the reduction of the noise level in the room, since sound waves cannot pass through the layer of air located among the fibers.At the same time, the denser the material, the smaller the air gap and the more sounds it passes through, therefore, the insulation can be chosen with average indicators of thermal conductivity and sound insulation.

Basalt insulation can be used to insulate the chimney, then even more heat will remain in the room where there is a stove or fireplace.

When using glass wool and slag wool, you will have to wear a protective suit, glasses and gloves, since thin fibers break and can get into the respiratory system, eyes and skin. These materials are also non-combustible, but they melt at much lower temperatures. In this case, the material loses its structure and useful properties.

Styrofoam

Insulation of an attic in a house with a cold roof can be done with foam. This material also has advantages:

• Low weight and cost.
• Does not emit harmful substances when heated, therefore it is chemically neutral and safe.
• Contains a flame retardant that does not support combustion.
• Microorganisms and mold do not start in the foam.
• Does not make the ceiling structure heavier.

Disadvantages:

• Low coefficient of strength, therefore, additional protection of the material is required in the form of boards laid on top with support on logs. This will require unnecessary costs and time.
• The material does not allow air to pass through, therefore dampness and condensation may form in the room.
• Rodents, which are found in private houses, damage the foam, build holes from it, so additional coverage is needed.

Styrofoam is used most often for outdoor work under plaster. As a heater for an attic in a private house, it is not profitable - it requires large investments to protect the material itself.

It is more profitable to insulate the ceiling with foam in a house with a cold roof from the inside, but this can lower the ceilings.

Penoplex (expanded polystyrene)

Insulation Penoplex is made from granules of synthetic material polystyrene or polystyrene foam. This is a heater, which is a porous structure with separately located cells. Honeycombs do not touch each other, which is a positive quality on the one hand, and a negative aspect on the other. The fact is that polystyrene foam does not allow moisture to pass through well, it will accumulate inside the room, causing dampness.

The advantage of polystyrene is its cost and low thickness. The air inside makes up 98% of the material, which is why it is so cheap. Compared to stone wool, the thermal conductivity is lower. To achieve good thermal insulation, it is necessary to buy thicker polystyrene foam, which will cost more.

Penoplex is flammable, therefore, in terms of fire safety, it is absolutely useless. The melting temperature is 75 degrees, so it should not be laid next to heating devices. In the attic, this could be the chimney from the stove.

Polyurethane foam

In terms of service life, as well as heat-retaining characteristics, it is worth paying attention to polyurethane foam, which is applied by spraying. In this case, there is no need to construct logs for laying mineral wool or expanded clay, to save money by purchasing cheap fragile materials.

In a short time, you can create a monolithic floor in the attic, in which rodents will not settle, mold will not start, and cracks will not appear. When using polyurethane foam, you do not have to buy additional vapor and waterproofing.

Bulk expanded clay

You can insulate the attic with expanded clay. It is a durable material that is used in bulk from prepared cells. If you need to move around the attic, you will have to build a floor on wooden logs from above. Advantages of expanded clay:

• strength;
• durability;
• does not absorb moisture;
• keeps warm well;
• allows air to pass through;
• can be used in combination with other materials, which is preferable.

Most often, expanded clay is combined with mineral wool or polyurethane foam is sprayed on it, so as not to waste time on the construction of the frame.

Insulation layer thickness

Thermal insulation materials of any density can be used to insulate an attic in a house with a cold roof, since the room is not residential. If you plan to lay mineral wool on roof slopes, you can prepare material of lower density and thickness, since as a result the ceiling insulation will be double, but laid in two places.

Builders recommend placing a thicker layer of insulation around the perimeter of the attic, since the greatest heat loss occurs in the corners.

For the convenience of moving along the soft insulation, it is necessary to build paths made of wood or other material, so as not to violate the properties when the heat-insulating layer is compressed.

Preparing the attic for insulation

Before starting work, it is necessary to calculate the area of ​​the room and the amount of building materials. The main thing is the thickness of the insulation, which is needed in the middle lane, where the temperature can drop to minus 30 degrees. The thickness of the mineral wool should be at least 20 cm.

After calculations:

• Remove all debris and dust so that the sealant does not absorb it.
• Fill roof gaps with construction foam.
• Remove sharp objects. They can damage the protective layer of the cotton wool.

After cleaning, you can bring in building materials, tools, as well as an additional backlight lamp.

Vapor barrier

According to the laws of physics, warm air saturated with steam will always rise upward, passing through walls and ceilings. This process is called diffusion.

Different materials have different degrees of vapor permeability. Condensation or moisture build-up between floors can be highly resistant to diffusion. In such places, the floors are usually made of wood, and the wood, saturated with moisture, loses its strength.

When the lower room warms up, and the upper one is cold, a vapor barrier is required. In the case of stone wool, you can buy a material with a hydrophobic coating that will not let steam into the cold room above, where water droplets form from it.

In technical documentation, there are two concepts: vapor resistance and vapor permeability coefficient. These are different concepts.

To organize the vapor barrier, two materials are used - a film to cover the entire area and adhesive tapes to connect the layers of hydrophobic insulation so that steam does not penetrate into the cracks.

The characteristics by which a vapor barrier is chosen should take into account strength (plastic film is not suitable), resistance to ultraviolet radiation, since the sun's rays sometimes enter the windows, which can damage the materials.

Waterproofing

To protect the attic from flooding, and ceilings and repairs from water drips, it is recommended to lay a layer of waterproofing material on the roof slopes.

• Weldable - overlapped and connected with a torch. The cheapest option is synthetic materials.
• Sprayable. A one-piece membrane film is created.
• Powder. Water is added to it just before installation.
• Liquid - suitable for concrete floors, absorbing into their surface.
• Bitumen-based coating.

Before you buy waterproofing, you need to re-read the properties: the material should allow air to pass through, but retain water. Some cheap films create a greenhouse effect in a cold, unheated attic, causing the walls to mold.

How to carry out the work correctly

Do-it-yourself attic insulation in a private house is carried out as follows:

1. If the attic space is not planned to be settled, it must be made ventilated. For this, ventilation gutters are installed in the roof.
2. It is recommended to insulate the old roof with a waterproofing layer of any type described above. This is to protect the mineral wool. A wooden structure is suitable, on which a film is stretched, or a spray.
3. If you insulate the slopes at the same time, it is recommended to start with them. Plates on one side are smeared with glue and attached to the inside of the roof. You can use self-tapping screws, substituting wide square plates under them. The roll insulation can be cut after it has been laid between the rafters.
4. A vapor barrier film is mounted on top of the slabs.
5. When installing insulation on the floor, logs are first built - a wooden frame, between which a roll or tiled layer is laid.
6. A vapor barrier is laid in front of the slabs, then slabs and waterproofing.

In order to be able to move freely throughout the entire area of ​​the attic, the logs are covered with durable material - wood or sheets of gypsum cardboard. This makes the appearance of the room more neat - if you wish, you can equip a workshop or storage of things there. If you want to save money, you can equip only paths to important objects, for example, to a chimney, dormer, ventilation.