How to insulate an attic from the inside with a broken roof. A quick way to insulate the attic roof of a private house from the inside without extra costs - the diagram and technology of thermal insulation inside! Why is attic roof insulation necessary?

not uncommon today. Increasing useful square meters using the attic is the easiest way. But in order for it to last throughout the year, the roof will have to be insulated. Therefore, in this article we will look at how to insulate an attic from the inside if the roof is already covered with roofing material. Let's figure out what thermal insulation materials can be used for this and what technologies to use for this.

And although many people believe that the attic is a type of attic, in fact, it is a completely different room, which differs in size from the first. And the main one is height. It must be at least 2.5 m.

In all other respects, this is an attic space, enclosed by a rafter system with a roof laid on it. If the roof is gable, then the attic is enclosed on both sides by gables - vertical walls supporting the rafter structure. It is in them that doors with access to the adjacent balcony are made. But the main walls of the room are the roof of the house with a certain slope of the slopes.

The technology for assembling the rafter system and roofing material is that it is necessary to lay between them, protecting wooden structures from unexpected leaks from the side of the roofing. This is a kind of safety net. On roofs, roll-type waterproofing material is mainly used, which is laid in strips from the eaves to the ridge with an overlap of 20-30 cm and attached to the rafter legs. The film is laid with a slight slack in case of thermal tension or expansion, plus the edges of adjacent strips must be secured with tape or self-adhesive tape.

Then wooden slats, called counter-lattice, are laid along the rafters, and transverse slats, called lathing, are mounted on them. The roofing material with fastening is laid on the latter.

The view from the inside of the attic shows rafters covered with a waterproofing layer on top. This is the design that will be needed. The question of how to properly insulate an attic from the inside with your own hands, we emphasize - with your own hands - requires first of all the determination of the insulation, or rather, its selection. Because not all modern thermal insulation materials can be used independently. But we will deal with them all, and we will definitely identify the best one.

Insulation for attic roofs

It should be noted that the slope of the slopes that define the walls of the attic is a cellular structure formed by rafter legs. It is between them that the thermal insulation material will need to be laid. Therefore, the main requirement for the latter is to be dense with clear shapes. This means that to insulate the attic roof of a private house, you will need to choose a slab material. Such insulation materials include mineral wool in mats and polystyrene foam boards, also known as high-density foam.

But, as mentioned above, today the market offers completely unique insulation technologies that do not use dense materials. One of them, which has shown itself on the most positive side, is liquid polyurethane foam. Let's start in order and consider each insulation separately.

Mineral wool

The definition of mineral wool includes several varieties of this building material: glass wool, slag wool, stone variety. When the conversation turns to attic insulation, we should talk specifically about the basalt variety, as the best today. It is its technical characteristics that we will consider.

Basically, basalt wool is divided by density. There are four positions here:

• P-75– used for insulation of pipes and horizontal surfaces;
• P-125– this is exactly the same material that is used to insulate attic walls from the inside with your own hands;
• PZh-175– for thermal insulation of metal and structures;
• PPZh-200– a very dense material used for thermal insulation of rigid load-bearing structures.

Expanded polystyrene boards

This material is often called polystyrene foam, which is correct. It’s just that polystyrene foam boards differ in density from the type that is used for packaging. Therefore, the material itself is very hard and durable, resistant to mechanical stress and humidity.

Let us immediately make a reservation that such material is not recommended for insulation due to its high flammability and love of rodents. But if you still intend to use it, then to insulate the attic roof it is better to take polystyrene foam boards with a density of at least 25 kg/m³.

Polyurethane foam (PPU)

This is a two-component thermal insulation material consisting of polyol and polyisocyanate. The two components are supplied separately in different containers, but during the application process they are mixed in one container and applied under pressure to the insulation areas through a hose and sprayer. In fact, polyurethane foam is a liquid substance that quickly hardens in air, turning into a hard and fairly durable coating.

The quality of insulation is based on the thermal conductivity characteristic. Comparing the three types, it can be noted that the weakest among them is mineral wool, the most ideal is polyurethane foam.

But this does not mean that everyone should use PPU. This material is not the cheapest and requires special equipment to apply it. However, it should be noted that equipment manufacturers today offer mini-stations that weigh only 30 kg. It contains two containers with components, hoses and a nozzle. The compressor will need to be purchased separately, but it is better to rent it from friends or rent.

And several more types of thermal insulation materials, which are used less frequently when insulating a roof from the inside with your own hands.

Glass wool

Ecowool

Penofol

How to insulate an attic for winter living - video and nuances of the process

So, we’ve decided on thermal insulation materials. Now let's look at how to properly insulate an attic roof.

Attention! When insulating an attic, it is necessary to adhere to two main nuances: the thickness of the layer being laid should be equal to the width of the rafter legs, the width of the insulation should be equal to slightly greater than the distance between the rafters.

Do-it-yourself insulation of the attic with mineral wool from the inside: video and photo instructions

Photo	Description of work
	The mineral wool is laid out on the attic floor. The required width is measured, which corresponds to the distance between the rafters, plus 2-3 cm. This is done so that the insulation fits tightly between the elements of the rafter system without leaving.
	Now a piece of insulation cut to the required dimensions must be laid between the rafter legs. If the slope of the roof slope is sufficiently flat, then the heat-insulating material under its own weight may fall out of the cell.
	Therefore, transverse slats are placed along the rafters from the inside, which are temporarily attached to the rafter legs.
	Instead of slats, you can use a strong thread, which is pulled over nails driven in a checkerboard pattern along the inner planes of the rafter legs.
	Insulation is laid under the padded slats.
	All that remains is to cover the thermal insulation cake with waterproofing film. Its purpose is to keep moist air vapors from penetrating into the thermal insulation layer. Because mineral wool is a hygroscopic material, and under the influence of humidity it begins to lose its properties.
	The waterproofing membrane is nailed with nails or metal staples to the rafter legs. Laying is carried out in overlapping stripes, starting from bottom to top.

Attention! If one layer of mineral wool for insulating the attic roof from the inside with your own hands is not enough to cover the width of the rafter legs, then a two-layer installation is performed. In this case, the slabs of material must be laid offset relative to each other. The joints between slabs in one layer should not be allowed to coincide with the joints in the second layer.

Insulating the attic with foam plastic

As mentioned above, it is not recommended to use polystyrene foam boards to insulate the attic. One of their main advantages is low, almost zero, water absorption. Therefore, there is no need to install protective layers for this insulation. That is, if during the construction of the roof a hydro- or vapor barrier membrane was not used under the roofing material, then PP slabs are the cheapest option for thermal insulation.

Photo	Description of work
	As in the case of mineral wool, polystyrene foam boards are cut to fit the distance between the rafters.
	The slabs, cut to size, are laid in the rafter system. It is necessary to indicate that there should be a space between the insulation and the roofing material, which will be used in the future as a means of removing not only moist air vapors, but also some harmful components of the heat-insulating material itself. Without forming this gap, PP cannot be laid.
	Another layer is laid on top of the rafters. Its main task is to cover the entire surface and prevent cold air from passing between the first layer and the rafters, because it is very difficult to lay PP boards tightly to the rafter structure. The second layer is attached to the rafters using self-tapping screws with a wide metal washer.

Insulation of roofs of different geometries

The methods of thermal insulation of a pitched roof, in which the slope is one plane, were described above. But attics are also formed under sloping roofs, so the question of insulating a sloping roof from the inside is no less relevant today. In principle, there are no serious differences in the technology itself, especially when it comes to the use of polyurethane foam. It is simply sprayed in one layer, without joints.

A sloping roof has a junction of two types of rafters, which form a hall. It is this area that is the most dangerous in terms of the penetration of cold air from the outside. Therefore, in the area where the two systems are connected, it is necessary to lay insulation materials without butts. This works best if mineral wool is used. It is flexible, so it can be shaped into a bend, that is, a transition from one slope to another.

With a sloping roof, the attic space is rarely left without a ceiling. It is built precisely at the transition level. Therefore, two slopes located in the same transitional plane are insulated, and then the ceiling itself is necessarily insulated. In some cases, if it is difficult to carry out thermal insulation of the upper slope or the goal is to save money, then the thermal insulation of the upper slope is not carried out, limiting itself to insulating the ceiling.

What mistakes can occur when insulating an attic from the inside?

When answering the question of how to properly insulate the roof of a house from the inside of an attic space with your own hands, you need to understand that this process itself is not complicated (not counting the use of polyurethane foam). But in order for the final result to correspond to a high degree of quality, it is necessary to take into account all the nuances of the technology and strictly follow the recommendations of specialists and manufacturers of thermal insulation materials. So, what to pay attention to:

1. Mineral wool should only be laid if there is a vapor barrier underneath the roofing material. Its main purpose is to remove air vapors that are located in the insulation itself.
2. There must be a gap between the thermal insulation cake and the roofing covering, which is used for ventilation of the roof. Therefore, the roofing material is laid on the sheathing, which is mounted on the counter-lattice.
3. If the angle of inclination of the slopes is less than 13°, then it is better not to organize an attic under such a roof. at this angle it comes off weakly, so there is a high probability of leaks.
4. If skylights are installed on roof slopes, care must be taken to install them airtight. It’s better not to do this yourself; call specialists.
5. If the thickness of the purchased insulation is greater than the width of the rafter legs, then slats can be punched along the lower edges of the latter.

So, we looked at how to properly insulate the roof of a private house from the attic side. If you have any questions, you can leave them in the comments. The editors of our site will definitely answer them.

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The desire to live better, to have spacious houses, separate rooms for each family member and guests is a completely natural desire of our fellow citizens. Improving living conditions can be achieved in two ways: building large and expensive houses using traditional technology or using modern solutions and converting attic spaces into residential areas. These are the so-called attic rooms; this method allows you to achieve your goals with minimal financial losses.

Thanks to the successful combination of housing quality, living comfort and the estimated cost of construction work, attic spaces are very popular among domestic developers. Currently, there are many technologies and special materials for insulating such premises. In order to make the right and informed choice, it is recommended to briefly familiarize yourself with their physical and operational characteristics.

The industry produces a wide range of materials used for insulating buildings. Regardless of the production technology, they all must meet several universal requirements.

These are general requirements, and popular insulation materials meet optimal performance to varying degrees.

What materials can be used to insulate an attic roof?

We will give a brief description of all possible options, and based on objective characteristics it will be easier for developers to make the right choice.

Table. Types of insulation for the attic

Prices for thermal insulation materials

Thermal insulation materials

Before making a decision on choosing insulation, it is recommended to carefully compare the objective characteristics of the materials, and not pay much attention to the marketing moves of manufacturers, but trust independent information.

And one more very important point: if the thickness of the insulation does not correspond to the climate zone, then you should not expect much effect from such insulation. There is no need to save, it is better to make the thickness with a margin of about five centimeters.

Usually a house is built quickly, often everything is put under the roof during the summer season. After interior decoration, you can move in, improve the local area and expand the functionality of the house. In this article we will tell you how to insulate an attic from the inside if the roof is already covered. The information will help you decide on the choice of material - this often depends on the initial conditions, and will explain the subtleties of its correct use.

Insulation of an already covered roof has its own characteristics that you need to know about Source pinterest.com

After this, you will speak the same language with the builders. Which is a good incentive for them to offer and demonstrate their best and do the work even better.

General points

Let's start with the fact that the attic is a bit of a special room. Its overall structure requires a careful, meticulous approach. And the insulation of the attic roof is even more so:

Mostly you will have to insulate vertical or inclined surfaces. Therefore, it is better to immediately exclude all soft “pliable” materials, namely mineral wool rolls.

It is advisable to navigate for materials with low dead weight. Since the rafter system is already experiencing significant loads from wind and snow. In addition, the load on load-bearing walls will not increase much.

Insulation is often required gables. They are not always made by analogy with a main wall. May be made of facing material. Or the frame is simply built for insulation.

It happens that the attic area significantly larger than the size of the house itself, while part of it rests on columns. In this case, you will also have to insulate the ceiling in contact with the street.

If the attic floor protrudes beyond the house, additional insulation of the floor is required Source metasold.com

It should be understood that the thickness of the insulation must correspond to the weather conditions of a particular climatic zone, and at the same time have a small margin. To gain the required thickness, the insulation is installed in several layers, and the relatively small dimensions require joining.

Important: splicing any insulation requires a careful approach. The joints of different layers should not be concentrated in one place. To prevent freezing, they should be spaced as far apart as possible. It is important to constantly remember this so as not to spoil the material, especially when insulating a sloping roof.

Video description

We will take a closer look at insulating a house with polystyrene foam. Find out how safe polystyrene foam is in our video:

It happens that the width of the rafters does not allow for the required thickness of insulation. To continue you need an additional frame. It is better to arrange it across, this will make the entire rafter system structurally even stronger. And insulation is more effective - additional insulation will cover the joints of the main insulation and rafters.

On our website you can find contacts of construction companies that offer turnkey house insulation services. You can communicate directly with representatives by visiting the “Low-Rise Country” exhibition of houses.

Preparation

All wooden surfaces must be treated with antiseptic and fireproof impregnations.

All wooden components must be treated with protective materials Source remontik.org

It is necessary to immediately identify “unreliable places” on structural elements. For example, the connection of the outer rafter to a pediment made of facing bricks. Or an overlapping connection between a rafter and a screed, made without insulation. It is necessary to eliminate the shortcomings - if possible, foam them or line them with a sealant. Otherwise, they will not be able to withstand through blowing and freezing.

It is necessary to minimize the use of metal fasteners. This is especially true for metal linings secured with bolts. Of course, the bolted connections will remain, but the plates should be made from thick, durable plywood and replaced. The remaining metal parts are painted with primer-enamel and covered with a layer of polyurethane foam. Metal directly in the insulation is a source of condensation and dampness.

Insulation of the rafter system

It’s great when the insulation of the attic from the inside was planned in advance, or “just in case” the constructive points for this were observed by the builders:

A roofing membrane is mounted on the rafters.

A counter-lattice is provided.

The pitch of the rafters is maintained corresponding to the common length or width of the insulation.

It is convenient to carry out insulation if it was planned at the construction stage Source bamban.ru

It is worth noting that these are ideal initial data, allowing you not to look for a “way out of the situation”, and to insulate the maximum volume of the attic with high quality without extra costs. Such conditions make it possible to use vapor-permeable insulation. And these are comfortable living conditions.

Insulation of an unprepared roof

When the decision to insulate is forced, the roof is usually not prepared. There is nothing terrible about this, it is even possible to choose the following options:

Insulate with materials that do not require waterproofing.

Build a special frame for living space.

In case of insulation of a roof that is not prepared for this, special compounds can help Source paspraypros.com

Foamed polyurethane foam can play a special role here. Although equipment is required for its application, insulation occurs in a continuous layer and does not depend on the design features of the roof.

Foamed polyurethane foam is one of them Source da.decorexpro.com

This also includes ecowool. Although its installation requires a roofing membrane, it is quite possible to make a continuous layer of insulation.

Video description

In our video we will look at how polystyrene foam is produced, is polystyrene foam harmful and where is it used?

Effective insulation

Stone wool

Due to their elasticity, the mats adhere well between the rafters and allow installation without additional fastening. And the relatively dense structure of stone wool prevents its shrinkage over time. Therefore, it has proven itself well on vertical surfaces.

Stone wool mats come in different thicknesses, and you can choose the one you need based on climatic conditions and other materials used Source pallazzo.su

To further reduce the risks, every 3 meters of height it is necessary to arrange supports for the insulation - add a horizontal frame element.

A commonly available popular material is penoplex. It is very effective as insulation. Its use is justified in areas of the country where it is not advisable to use mineral wool - a large thickness is needed, which significantly steals space, and the cost is prohibitive.

Under normal conditions, it saves significant space when every unit of volume is important:

It can be mounted between rafters of small width, and the insulation will be effective.

It does not require additional waterproofing, since it does not allow water to pass through. That is, the absence of a roofing membrane is not critical.

However, it is still desirable to have a ventilation gap with the roof to quickly remove condensate vapors. This way the rafters will last much longer, because they are not protected.

Extruded polystyrene foam does not require mandatory waterproofing Source pt.decorexpro.com

When insulating with penoplex, it would be useful to take measures for increased fire safety. For example, use open installation of electrical wiring, laying it down constructively, as a design solution. The thing is that penoplex itself does not support combustion, but at high temperatures it melts very quickly.

Proper completion of work

The insulation has been installed, but the process must also be completed correctly. It must be protected from damp vapors from the room. For this, a vapor barrier film is installed. Moreover, the overall result greatly depends on the thoroughness of execution. Although each package is supplied with instructions, let us briefly repeat:

The subsequent canvas overlaps the previous one by at least 15 cm.

The joints are taped with special tape.

However, attic vapor barrier has a dual purpose. Oddly enough, it also protects the residents themselves. The fact is that vapor-permeable insulation is not strong enough and can be slightly weathered. From the outside this is not so important, plus it is protected by the roofing membrane. And inside it is necessary to exclude even the minimal possibility of the insulation components being released into the air - to reliably cover it.

The final stage is covering the insulation with canvases, on which the finishing is subsequently applied. Source obustroeno.com

Of course, this does not apply to Penoplex. But it is also recommended to protect against it; an effective material is penofol.

As for insulation of any type. In addition to the vapor barrier device, a technique that at first glance is unnecessary, but effective, is often used. Before finishing, intermediate, seemingly unnecessary material is installed. It can be OSB, GVL or GKL - it depends on the design. Moreover, the technology is fully observed - all joints are carefully sealed. This is an additional barrier against the unwanted effects of materials.

Video description

About insulating the attic from the inside in the video:

Results

It turns out that insulating a roof from the inside if the roof is already covered is quite possible to do efficiently. Moreover, not only having planned everything in advance, but also on a long-ready roof that was completely unsuitable for this. Now, knowing the intricacies of the process, it is much easier to choose a good performer for such an important task.

Statistics show that more than 50% of residential under-roof spaces in the Russian Federation are insulated with mineral wool. Does the popularity of the material indicate its undeniable advantages? This review examines the insulation of the attic from the inside with mineral wool with your own hands and analyzes the method from a functional and technological point of view.

Plates, mats and rolled materials made of basalt fibers, used to insulate the attic from the inside, attract developers and builders with three important properties:

Mineral wool is an effective and popular insulation material in Russia

• Fire safety. All brands of mineral wool belong to the NG category.
• Vapor permeability.
  

  Due to its ability to absorb condensation and evaporate it when the temperature rises, mineral wool works well in contact with wooden rafters. It protects them from waterlogging, which causes the development of fungus and wood rotting.

• Good noise-absorbing characteristics. Randomly oriented fibers most effectively reduce the level of high-frequency noise, which is especially intrusive and irritating in the rain.

The described characteristics, to a much greater extent than the cost, influence the choice of this type of insulation for attic insulation. However, different brands of basalt thermal insulation differ significantly from each other in a number of other parameters. Insulating an attic from the inside of a room with your own hands requires some experience in working with mineral wool and imposes additional restrictions on the properties of the material: this becomes clear from the video posted in the “Self-installation algorithm” section.

Among these additional qualities are:

1. Material format. For laying between rafter beams, the width of the thermal insulation should be 600 - 610 mm.
2. Density. When working alone, the less the slab or section of it weighs, the better.
3. Elasticity and fairly high rigidity. This quality greatly simplifies the insulation of the attic with mineral wool.
4. Availability of large thicknesses - 100, 150, 200 mm.

It is a common misconception that the high density of basalt insulation indicates its increased energy efficiency, and the low density indicates low rigidity and inability to hold its shape. However, there is no direct relationship between thermal conductivity and stiffness and density. The length and thickness of the fibers, as well as the type of their orientation, are of decisive importance.

Mineral wool in the form of slabs is convenient for insulating the attic alone

We compared the actual parameters of mineral wool brands recommended by leading manufacturers for roof insulation. All four stated requirements are met by only three names: Rockmin and Rockmin plus (Rockwool brand), as well as Rocklight TechnoNIKOL slabs. Plates of these brands (formats 1000×600 mm and 1200×600 mm) with a thickness of 100 mm weigh respectively 1.6 kg; 2.1 kg and 2.9 kg. At the same time, they are elastic and hold their shape well.

There are many types of mineral wool insulation that exceed those we recommend in terms of thermal resistance or stiffness. But they are all of the wrong format, or very heavy or not flexible enough, and therefore inconvenient for working alone.

Roofing pie composition

Insulating a residential attic with mineral wool requires mandatory compensation for the weaknesses of this material: the ability to absorb moisture coming from the room, as well as high airflow and low resistance to precipitation. Therefore, in the roofing pie, provided that fiber insulation is used, two and sometimes three membranes are introduced. In the direction from the room to the outside, the layers are arranged in the following order:

Scheme of attic insulation with mineral wool

1. Finishing ceiling cladding. The warmest material for this layer is drywall and a layer of putty (taken into account separately in the thermal calculation).
2. The air gap formed by the sheathing for attaching the finishing cladding. Equal to the thickness of the slats (or galvanized profiles) of the sheathing. This gap is not necessary for the operation of the heat-insulating system.
3. Vapor barrier film. Protects the insulation from steam rising from the room.
4. Basic insulation (2 - 3 layers of mineral wool).
5. High diffusion membrane (waterproofing). Its peculiarity is the one-way passage of water. Moisture coming from below (evaporated by mineral wool) should freely penetrate through the membrane, and water coming from above (precipitation and condensation) should flow under the roofing down to the street. Films of this type combine the functions of a water barrier and wind protection. In domestic practice, three-layer isospan membranes have proven themselves well. It is better to use Izospan AQ proff for the attic, which is characterized by high strength and good steam transmission (1000 g/m2 per day). There is no need for a gap between isospan and mineral wool.
6. Ventilation gap between the membrane and the roof deck. It is formed by sheathing strips located perpendicular to the rafters in plan. The thickness of the lathing is usually 4 - 6 cm.
7. Roofing flooring.

Sufficient insulation thickness

To determine the required thickness of mineral wool, you should choose one of the independent online thermal calculators (not owned by any insulation material manufacturer). In the filters, you must specify the region and all components of the roofing pie, indicating materials and thicknesses. Each air gap is also a significant insulation layer.

The thickness of the insulation for the attic must be accurately calculated

After this, the calculation will show the final indoor temperature. Using the method of successive approximations, you can find the value of all thermal insulation parameters that provide the required level of comfort in the attic.

In most regions of the European part of the Russian Federation, the required thickness of mineral wool for internal insulation of an attic is 280 - 300 mm.

Often, developers are content with values ​​of 200 - 250 mm, for the reason that “this corresponds to the geometry of the rafters” and “this has been tested in practice.” They simply ignore the fact that heat in the attic is compensated by heating systems located on the ground floor. The money saved on attic insulation results in significant annual energy waste.

Table: comparative characteristics of various insulation materials and the required thickness depending on thermal conductivity

Technology for self-installation of mineral wool

First, you need to make sure that the outer elements of the roofing pie (or at least the waterproofing layer) have already been installed. This is necessary to protect the mineral wool from atmospheric moisture before installing the outer membrane.

Place mineral wool tightly between floor beams or posts

Next, the width of the openings between the rafter beams is checked. If the size ranges between 550 mm and 600 mm, then you will not have to cut the insulation (you can use the factory width of the slabs 600 - 610 mm). If the distance between the rafters is more than 600 mm, it will be necessary to cut fragments of the required width from mineral wool slabs based on the installation compression of 20 - 30 mm. For example, if the rafter niche has a width of 720 mm, then sections of 700x600 mm are cut out of 1200x600 mm slabs. Residues 500×600 are accumulated for use in insulating various contours (for attic walls, around window openings, for laying crossbars on top, etc.)

The second method involves cutting rectangular slabs diagonally and relative displacement of the halves along this diagonal. When shifted, the overall width increases, ensuring that the ends of the wool rest against the vertical edges of the rafters. However, in this case, for a tight connection, the following slabs will have to be cut curvilinearly from the outside.

Installation of mineral wool and further operations are carried out alone using the following techniques:

Fastening mineral wool with nylon thread

1. If there are no significant differences in width in the openings between the rafters, you can install mineral wool slabs without preparatory work. Pressing the material by 20 - 30 mm allows you to lay out all the insulation elements from the inside of the room into the roof slope. Otherwise, to support the wool, a temporary (removable) sheathing of planks, boards, or nylon thread (non-removable) is used, stretched along the lower edges of the rafters in a zigzag using a stapler. Layers of mineral wool are laid out in a checkerboard pattern to cover the joints.
2. A vapor barrier film is stapled from below to the ends of the rafters. It must be joined with an overlap, gluing the joints with special tape.
3. The lathing is installed to install the final ceiling cladding.

Video: how to insulate the roof of an attic floor with mineral wool (Isover Pro 100 mm and Ursa Pure One 50 mm)

The total thickness of the insulation was 250 mm. The insulation is fixed using a 50×40mm beam. To eliminate sagging mineral wool, the author of the video additionally uses twine, which is stapled to the block.

Insulation of mauerlat and walls

The insulation of the attic walls should form a closed loop with the insulation of the roof slopes. Thermal calculations for walls are carried out separately. In most cases, it shows the required insulation thickness 1.5 times less than for the roof.

Mauerlat is a log or beam that serves to transmit and average pressure from the rafter beams to the upper end of the wall. It is recommended to insulate the Mauerlat before installing the hydrobarrier. The Mauerlat is insulated from above and from the street side. Then the membrane is installed.

Video to help: why moisture forms on the roof of an attic insulated with mineral wool

Conclusion

In addition to the high functional properties of mineral wool used in residential roofing areas, consumers are attracted by the possibility of significant savings. The main source of this is not the price of the material, but the independent performance of the work. However, for installation carried out alone, a number of additional requirements are imposed on the fibrous insulating material. Only taking them into account when choosing a brand of cotton wool guarantees you calm, measured work.

Insulating an attic roof: video instructions

The diagram shows the correct order of arrangement of elements of the attic roof thermal insulation system

What is the reason for this particular arrangement of layers? Elementary laws of physics. Let's imagine that in winter a decent layer of snow fell, which, by the way, is a natural heat insulator. As a result of the life activity of people living in an attic house, warm air will rise from the inside to the surface of the roof.

The snow covering it will melt. And as soon as the temperature outside drops below zero, a crust of ice forms, which no longer has any heat-insulating properties. The essence of proper insulation of an attic roof is to prevent snow from melting in winter and scorching heat from penetrating in summer.

Diagram of air movement in the under-roof space, and the operation of the vapor barrier when insulating the attic roof

The rows are marked using a cord attached to a counter-lattice, which is located on opposite sides of the roof slope (read also the article: “Lathing step under corrugated sheeting”).

The desire of many owners of country houses to make maximum use of the space of the house forces them to pay attention to the attic. It often happens that it is easier to equip an attic than to expand the house by adding a residential building to it. Since the attic is part of the roof of the house, it is with the thermal insulation of the roof that the arrangement of the attic floor should begin. Let's look at how to properly insulate an attic with mineral wool and show detailed video instructions on the topic.

You should insulate the attic with mineral wool and equip the attic for a room if the roof of the house allows the ceiling in this room to be of sufficient height and it is possible to strengthen the interfloor ceilings so that it is safe to walk in the attic.

If these two conditions are met, then you can safely begin to independently insulate the attic with basalt mineral wool for living in the winter.

We reviewed various brands of mineral wool, their purpose and characteristics in the section “Inorganic Thermal Insulation”. Therefore, we will not dwell on this topic separately.

• Features of insulation and materials for thermal insulation of the attic from the inside with your own hands
• Do-it-yourself methods for insulating an attic
• The procedure for insulating the roof and walls of the attic
• Wall insulation

An attic is an attic space equipped for human habitation or any household needs (greenhouse, office, etc.). Depending on what the room is intended for, its layout and the type of attic roof, the configuration may be different, but the general requirements in accordance with which the attic must be insulated from the inside remain the same.

Layout of insulation in the attic roof.

You need to understand that this room, unlike all the others, is colder, because... there is no “thermal cushion” on top. That is why insulation of the attic of a house from the inside, done with your own hands, must be of especially high quality. Based on this, you should choose the insulation material with which the insulation will be performed.

The difficulty is that the surfaces are uneven, because There are rafter beams under the roof that will have to be bypassed. The waterproofing layer will need to be brought under the roof in order for the condensate to drain. In the process of organizing work on insulating the roof and walls of the attic from the inside with your own hands, it is necessary to take into account that the end walls also need to be covered, because It is through them that a huge amount of heat escapes.

Attic insulation scheme.

Each private house has its own characteristics, shape and configuration of the roof, material of the walls and roofing. Consequently, for each individual house there may be some special, clarifying recommendations, according to which you need to insulate the roof and walls of the attic of a private house from the inside with your own hands.

To ensure high-quality and reliable insulation, you need to choose the right materials. The choice of material with which it is better to insulate the roof and walls of the attic of a house from the inside with your own hands depends on many factors: roof structure, roofing material, climate in the area, etc.

Polystyrene foam is one of the least expensive and most popular materials with which you can insulate the attic of a private house from the inside with your own hands. It is easy to process and install. However, it has low vapor permeability, which means the room may be damp. So, if the attic will be used as a living space, it is better to insulate it with another material.

You can properly and efficiently insulate a residential attic with your own hands using expanded polystyrene. When laying this material there will be practically no joints.

Mineral wool is an excellent material in all respects.

Having high strength, basalt mineral wool is fireproof, practically does not conduct heat and does not absorb moisture. Since this material is elastic, it holds well at the installation site, resting its edges on the rafters. So it is best to insulate the walls of a residential attic from the inside with this material. you can properly insulate your home with mineral wool, even if you have never worked with this material before.

In addition to insulation, it is necessary to install waterproofing, vapor barrier and a ventilation system. A properly constructed waterproofing membrane will perform the following functions:

• ensure protection of structural elements from precipitation;
• prevent moisture from penetrating into the insulation.

Waterproofing must be laid on a layer of insulation. Among the waterproofing films, the following are distinguished:

• diffusion and breathing superdiffusion;
• anti-condensation waterproofing.

The vapor barrier consists of several layers of reinforced polyethylene film, which provides good protection of the structure from condensation.

A ventilation system is needed to ensure the outflow of exhaust air and the influx of fresh air, and to effectively maintain normal air humidity in the attic room.

Attic insulation, diagram.

There are several methods according to which you can properly insulate the attic of a house from the inside with your own hands.

Insulation between existing rafters is one of the most commonly used methods. With this method, the insulation is laid directly on the waterproofing, to the entire height of the rafter legs. The slabs should be 10-15 mm wider than the gaps between the rafters.

Thermal insulation above the rafters. It is immediately necessary to carry out all the finishing work from the inside, and lay the thermal insulation material on the rafters under the roofing.

Another popular method is to insulate the attic under the rafters. This method is not used in residential construction and for low-rise buildings, but for industrial buildings it is the best option.

There are also combined schemes. The most popular scheme includes insulation under the rafters and between them. In this case, the rafters themselves are completely overlapped. The vapor barrier film must be laid on top of a layer of thermal insulation material. Among the disadvantages, one can highlight a slight reduction in the usable space of the attic itself.

Attic insulation scheme: insulation, vapor barrier, waterproofing.

To insulate an attic with your own hands, you will need the following materials and tools:

• foam sheets or mineral wool;
• waterproofing film;
• wooden blocks;
• vapor barrier film;
• scissors;
• sharp knife;
• construction stapler;
• nails;
• polyurethane foam.

First of all, waterproofing needs to be laid along the rafters. The film is laid along the entire height - from the bottom to the ridge of the roof. However, this is not done in all cases, because roofing material sometimes also serves as such an insulator. If the covering is made, for example, of roofing iron, it will be quite sufficient.

When installing this material, you need to remember that some distance should be left between it and the roof. This air gap is necessary to ensure high-quality ventilation at the installation site of the insulation. The thickness of the air gap depends on the covering material of your roof. If the material has a wavy shape (metal tiles, roof tiles), then the air gap should be at least 25 mm.

Another important point is that the thickness of the insulator slabs and rafters can be different. If the slabs are “thinner”, the first layer is laid between the rafters, and the second must be laid on the rafters. If the slabs are thicker, wooden slats must be placed on the rafters.

To protect the thermal insulation material from excessive humidity, a vapor barrier must be applied on top. As you know, warm air tends upward and condenses there. That is why such protection is mandatory. Polyethylene film, glassine, foil materials, and roofing felt are used as materials for the vapor barrier layer.

Wall insulation

How to build a mansard roof - step by step guide

An attic, which makes it possible to effectively use the floor space of a private house, is a rather complex design. As a rule, homeowners entrust its construction to experienced roofers. But if you are an expert in carpentry and are not afraid of difficulties, then you can certainly cope with the task yourself.

To construct an attic floor instead of a conventional attic, the following types of roofs are suitable (shown in the diagram below):

• regular gable with a slope of 45° or more (steep);
• broken roof;
• four-slope, half-hip.

Note. As can be seen from the diagram, various half-hip roofings are complicated gable roofs, so there is no point in considering them separately. In terms of design, the multi-gable structure shown in the photo is of interest, but its construction requires considerable experience.

The gable mansard roof is the simplest to implement and is economical in terms of material consumption. But you will have to pay for this with a smaller usable area and sloping walls of the attached floor, which do not allow the placement of tall furniture. This will not be a problem if you plan to set up a bedroom in the attic - the beds will easily stand near the longitudinal walls. Another way to solve the issue is to raise the rafter system to the required height, as shown in the drawing below.

Roofing with broken shapes is the most popular option, since it allows you to create full-fledged living rooms upstairs. If you do not provide protruding windows on its slopes, then in terms of installation technology such a roof is not much more complicated than a gable roof, although the consumption of building materials will increase. To make your choice easier, we suggest considering and comparing the 3 most common options for an attic superstructure for a private house with standard dimensions of 6 x 6 m:

1. Steep roof with two slopes inclined at an angle of 45°.
2. A broken structure, where the lower rafters are inclined at an angle of 60°, and the upper ones - 30°.
3. The same as option 1, only the trusses are raised to a height of 60 cm, and the rafter legs are at an angle of 37.5°.

For convenience, we depicted all three structures on one drawing, which can be taken as a basis for future construction.

Note. A board with a cross section of 50 x 150 mm was taken as the main building material for the manufacture of rafters and other frame elements.

To choose the best of the three options, we suggest studying the comparison table, which presents the parameters of attic rooms per 1 linear meter of building length.

Knowing the length of the roof slopes indicated in the plate, you can approximately estimate the consumption of building materials for the frame, covering and insulation. The following table makes it possible to estimate the total area of ​​the rooms on the second floor when implementing all 3 solutions in private houses with different sizes.

The rafters of a do-it-yourself attic must withstand the following loads throughout their entire service life:

• own weight;
• weight of roofing and insulation;
• maximum gusts of wind for a given area;
• snow cover pressure.

Reference. When the roof slope is more than 45°, snow practically does not linger on it, and at 60° it is not taken into account at all in the calculations. But wind pressure increases due to the height of the structure and its position, which is close to vertical.

The result of the calculations should be 2 parameters - the cross-section of the rafters with beams (otherwise known as tie rods) and the pitch of their installation. It is a mistake to think that the size of the wooden beams of the roof increases along with the loads on it. Maximum structural rigidity is achieved through the use of trusses made of logs with a diameter of 120-200 mm or lumber with a thickness of 40 to 200 mm, installed in increments of 50-120 cm. If you are not a civil engineer, you will not be able to determine these values ​​more precisely, since the methodology quite complicated.

We will explain the calculation method with an example. Let’s assume that the snow load on a flat surface (projection of a pitched roof) in your area is 100 kg/m², the slope is 60°, the span length is 4.5 m (before the brace), the pitch of the rafters is 120 cm. The roofing is slate. We count:

1. Real weight of snow cover: 100 x 0.32 = 32 kg/m². The slope coefficient of 0.32 is taken from Table 2 below.
2. The specific gravity of a slate covering with a regular profile is 25 kg/m².
3. Total specific gravity – 32 25 = 60 kg/m².
4. We calculate the specific gravity per 1 linear meter of rafters, multiplying 60 kg/m² by an installation step of 1.2 m. We get 72 kg.
5. We return to table No. 1 and select the cross-section of the beam according to the span length. We accept a load of 100 kg per 1 line of rafters (with a margin). A log with a diameter of 140 mm, a board 40 x 200 mm and other materials whose dimensions are in the same horizontal line are suitable.

Reference. When installing a sloping mansard roof, 2 types of rafters are used - layered and hanging. On a gable roof, only hanging roofs are used; the difference between them is shown in the diagram.

The proposed method is suitable for small rectangular houses measuring 6 x 6 m. To build a mansard roof on a large cottage, it is strongly recommended to contact specialist designers for calculations.

The simplified method presented below involves the installation of an attic sloping roof in 2 stages: assembly of roof trusses on the ground and subsequent installation on the finished walls of a timber or log house. The structural material is boards with a section of 15 x 5 and 10 x 5 cm with a standard length of 6 m.

Start of assembly - formation of the upper chord of the rafter system

The technology looks like this step by step:

1. Prepare the beams of the lower chord of the truss, taking into account roof overhangs of 25-27 cm on each side. If the length of the beam is not enough, it needs to be increased using an overlay of the same section, nailed.
2. Lay the beam on the ground and attach vertical posts to it with corners, forming the walls of the attic room. Install the ceiling beam and the ridge support (headstock), then attach two hanging rafter boards to it and the corners of the frame for marking, as done in the photo.
3. Cut the elements into place and secure them. From the remaining parts of the boards, make layered (lower) rafter legs in the same way and nail them to the frame. The farm is ready.
4. Make the remaining trusses using the same method.

Advice. As a rule, windows or doors to the balcony are provided on the front gables. It is also convenient to make racks and belts for their installation on the ground, as well as to cover the openings with clapboard.

The finished frames are lifted onto the walls and fixed in place one by one, starting from the first pediment. To prevent it from falling, install spacers and nail them to the walls of the log house. The second and subsequent trusses are placed in the design position and connected to each other with boards.

After placing the rafters, they must be secured to the walls in the following ways:

• staples to the second top crown of logs or beams;
• on steel corners and galvanized screws, as shown in the photo.

What is the best way to insulate an attic roof?

As mentioned above, the most popular material for insulating an attic roof is mineral wool. She is good, but not at all ideal: she is afraid of moisture. That is why it requires such careful protection from all sides so that it retains its properties.

The roof is sheathed with foam plastic or extruded polystyrene foam - EPS. Polystyrene foam (grades PSB-S-25, PSB-S-35) has good characteristics, but when burned it emits harmful substances, although there are self-extinguishing brands (with special additives). It is better to use them for roof insulation.

The main advantage of polystyrene foam: low price. It is easy to install: it is placed between the rafters, all joints are sealed with polyurethane foam. It is convenient to insulate the attic from the inside with polystyrene foam: you order slabs of the required size - 10-15 mm larger than the clearance between the rafters - and place them tightly. Due to their elasticity, they hold up very well.

A ventilation gap is also left on the roof side and waterproofing is installed. But it protects the wooden structure more, since polystyrene foam is not afraid of moisture, practically does not absorb it, and does not conduct steam. This is where the main drawback lies. Since the material does not allow steam to pass through, a good ventilation system is needed in the attic, and this is an additional cost.

EPPS has the best characteristics: under equal conditions, its thickness is two times less than mineral wool of the specified density and one and a half times less than that of polystyrene foam. It also has a locking system that reduces the risk of gaps through which heat can escape. Another plus: extruded polystyrene foam is not liked by mice and insects; fungi and mold do not grow on it. What limits its use: a respectable price. You also need a ventilation system.

EPS brands - Ekstrol, STIREKS, PENOPLEX, URSA XPS, Technoplex, PRIMAPLEX, Styrofoam, KINPLAST, Teploizolit, GREENPLEX. Although the technology is the same, there are some differences in characteristics, so compare when choosing.

Not long ago, a new type of insulation appeared: expanded polystyrene foam. It is applied in liquid form to the surface, reacting with air, increasing in size many times over, filling all the cracks and forming a monolithic layer. This is, perhaps, the only way today to correct the situation and efficiently insulate the attic if, when installing the roofing, they forgot to lay a layer of waterproofing.

Ecowool

This insulation has good characteristics (thermal conductivity coefficient 0.036-0.040 W/m² °C), but has a special application technology. It is necessary to organize a closed cavity into which the composition will be poured. In the case of an attic roof, the side parts are rafters; sheet material (fibreboard, gypsum fiber board, plywood, etc.) is nailed to them from below and above.

A feeding sleeve is launched into the formed cavity, from which loosened cotton wool emerges under pressure. It fills all cavities, forming a single layer of insulation.

The main advantage of ecowool compared to all the insulation described above: it conducts vapor. It can absorb moisture up to 20% of the volume and then release it. That is, there is no need to organize a vapor barrier: humidity is regulated naturally, as is the case with wood. The ventilation gap between the roof and the insulation should be the same, as should the properly organized movement of air masses in it.

There are four most important criteria based on which it is necessary to choose high-quality insulation for an attic roof:

• Thermal conductivity;
• Moisture resistance;
• Fire safety;
• Ecological cleanliness.

The first parameter can be called decisive, since its thickness, number of layers, and most importantly, efficiency depend on how low the thermal conductivity of the material you choose is.

Important: Insulation for an attic roof with a thermal conductivity coefficient of no higher than 0.05 W/m*K can be considered sufficiently high quality and reliable.

The second indicator is also important, especially for an attic rafter system made of wood. The resistance of the insulation to moisture will allow you to worry less about the possibility of damage and rotting of the wood. Why fire safety of insulating materials is important is probably unnecessary to say. And finally, the environmental friendliness of the insulation in the case of attic rooms is also of great importance, especially if it is a bedroom or a children's room in the attic.

Comparative table of building and finishing materials indicating their thermal conductivity coefficient

As follows from the figure above, insulating an attic roof with ecowool is an excellent solution, since this mineral insulation meets all four criteria for choosing a material. However, it cannot be called the most affordable, so many craftsmen refuse to use ecowool in favor of cheaper, but no less effective insulation materials.

• Basalt wool;
• Glass wool;
• Extruded polystyrene foam;
• Styrofoam.

First, let's consider the most important question - what is better to insulate the attic with foam plastic or mineral wool. Let's determine which thermal insulation material is suitable for proper insulation of the roof of the attic floor.

To do this, the following parameters should be taken into account: thermal conductivity coefficient, resistance to high temperatures and moisture, fire safety, environmental friendliness and low weight.

Most of the listed requirements are met by fiberglass or mineral wool. Unlike basalt insulation, Technoplex polystyrene foam does not withstand high temperatures and is a very flammable material.

Knauf glass wool and Rocklight basalt wool are fire-resistant and fireproof materials, and with high-quality vapor barrier, mineral wool will not be affected by moisture.

Comparison of building materials by thermal conductivity

Mineral wool is made from natural material – basalt. The material has a density from 18 to 45 kg/m³ and has good heat-insulating and sound-absorbing properties.

When the question arises about insulating a roof structure, the first thing to consider is all kinds of materials that are intended for such purposes. Which insulation is best for an attic roof?

Taking into account all the individual design parameters, a material is selected from those offered on the market in accordance with their characteristics.

When choosing a material, it is worth starting from the individual situation, because some of the disadvantages of the material in a certain situation become advantages.

These types of materials are the most popular, especially for the DIY insulation process. They are characterized by a high level of thermal conductivity and fire safety.

Laying the insulation is quite simple, and there are no gaps between it. During operation, the shape remains the same and does not change, which ensures a long service life.

In addition, the sound insulation properties of these types of insulation are also at a high level. The cost of insulation is low, but it is safe to use and environmentally friendly.

Their differences lie in the raw materials used for production. The mineral variety is made from molten rocks, and glass wool is made from molten glass. Regarding the thermal threshold, glass wool has a lower threshold than its mineral counterpart, but is resistant to freezing.

The characteristics of these insulation materials also have disadvantages that should be taken into account when choosing. Due to the fact that the level of moisture and vapor absorption is quite high, when wet it loses most of its properties, which leads to the need for a complete re-equipment of the roof insulation layer.