Internal insulation of an attic is one of the most difficult construction tasks. And all because the result is important here: how the roofing pie will behave in winter, whether there will be any leaks, whether there will be a smell of dampness, and whether it will all have to be dismantled later. Why such difficulties? The fact is that no matter how carefully the budget for building a house is planned, as a rule, it is still not enough for everything. To the point that even the owners of the future family home decide to buy laminate flooring cheaper - just to finish the repairs and just start living. And the most popular expense item, which is immediately cut as soon as the lack of funds becomes clear, is attic insulation. “Later, in the future,” the owners promise themselves, especially since insulating the attic from the inside is not a problem at all, and you can start it at any time, even in winter.
In fact, there are a lot of subtleties and nuances here, and therefore, if you have already taken up this matter, carefully study this article. And everything will work out!
Why do problems arise?
There are statistics: up to 30% of attics have to be remodeled after the first winter. The roof covering, interior trim and films are removed, and the insulation is dried. In this case, a lot of materials have to be thrown away, and this is another unplanned expense. Even if you hired a professional team of builders, this is not a guarantee of the well-being of the future attic, especially if the roofing cake is thought out without taking into account the peculiarities of the local climate.
Why is this happening? Thus, in Russia, dampness, cold and round-the-clock negative temperatures are not uncommon. And the lower the ambient temperature, the greater the volume of steam that penetrates through the vapor barrier - all due to an increase in the partial pressure difference. And at the same time, the migration of moisture through the cold membrane slows down significantly, although it does not stop. Bottom line: the situation is even worse than under standard tested conditions. And therefore, it is impossible to test the vapor permeability of a roofing pie in European conditions, and at the same time expect the same good result in the Siberian regions.
Here's a simple illustration to help you understand what we're talking about here:
Note that the maximum water vapor pressure on the roofing pie is in the residential attic. And it’s not even that there are people in such a room much more often than in an ordinary cold attic - it’s just that the pressure of warm air is additionally added to the steam pressure. Moreover, these processes are so obvious that they can be observed in the form of real leaks!
The fact is that wet insulation loses its properties very quickly. And the more humid the air that reaches it, the faster the thermal insulation decreases. For example, basalt insulation with a humidity of only 5% already loses its heat by 20% than dry insulation.
For example, just one cubic meter of air space, if its relative humidity is 100%, at a temperature of 20C contains 17.3 grams of water - simply in the form of steam. And the lower the temperature, the more difficult it is for air to hold water in a bound state. And when the temperature drops to 16C, there will be only 13.6 grams of water vapor in the same air, and the rest will settle as water in the insulation. Let us conclude: moisture in the insulation appears due to the condensation of excess water vapor from the air as the temperature decreases. And it must be actively fought. And this is far from the only problem - now we will deal with them all.
Let's get started with insulation - work technology
Let's start with the first problem - insufficient thickness of the joists if you insulate the attic after the construction of the entire house and installation of the roofing. Why is that? Let's take a closer look at this issue.
Thus, attic insulation can be divided into basic and additional. Basic is insulation, which is carried out during the construction of the roof of the house and involves the use of lightweight insulation directly into the rafter structure. But additional insulation already turns an uninhabited attic into a full-fledged attic.
With basic insulation, the main task is to minimize the heat loss of the house through the roof, and such basic insulation can easily replace additional internal insulation, if only you choose the insulation wisely, do not skimp on its thickness and think through the rafter system well. This is often done by those builders of their own houses who understand that 20 rooms may not be enough in the future, and additional space for a billiard room, library or sauna cannot interfere. And therefore, it is better to initially build it completely residential, and not finish something later.
But, if during the construction of your house you decided to make do with basic thermal insulation and now you have enthusiastically taken up the task of arranging a habitable and cozy attic, then the only option for you is additional internal insulation with all its nuances, the main one of which is the insufficient thickness of the rafters, which were not originally designed for dense internal insulation. But the problem is completely solvable, as proof of which we have prepared for you detailed master class:
Now let’s move on to more insidious aspects that are no less important: proper vapor barrier and waterproofing, which you may have to redo.
No - dampness and smudges!
For any insulation it is extremely important to create the right conditions, otherwise the material will quickly become damp and, instead of a source of heat, it will become a source of dampness, mold and cold. What are these conditions? Let's take a closer look!
What is dew point?
The first and most important quality of any insulation is low thermal conductivity. Thanks to it, the insulating layer strictly separates the warm air inside from the cold outside. It would seem that they inserted insulation into the rafters, secured it - and that’s all that else is needed? Not so!
Firstly, from the outside, the whole thing must be carefully waterproofed from rain and damp air, because... In this regard, such a roofing pie is a real sponge. Secondly, any insulation also has a second quality - vapor permeability, i.e. "breathes". Now let’s remember physics: the warm, humid air inside the room under the roof (always humid!), without finding an obstacle, easily passes inside the insulation and collides with its colder part, the one that is closer to the roofing pie. And there this air condenses, settling in the form of droplets, which is called the dew point. What's the point of external waterproofing then? Mineral wool insulation is especially susceptible to this phenomenon, note.
Therefore, our first task is to ensure that as little steam as possible passes through the insulation, because even super-diffuse membranes in the cold do a poor job of removing water vapor, due to a significant slowdown in moisture transfer processes. And this is a question of proper vapor barrier of the attic insulation.
Here is a clear example of the unpleasant consequences of ignoring the concept of dew point:
Vapor barrier: warm European winters and Russian frosts
In fact, in Western Europe, where winters have always been mild, there is no need for vapor barriers with special properties - simple packaging films are quite suitable. So they sometimes end up in Russia, although their vapor barrier properties are not high. These are LDPE roll films, which stands for “low density polyethylene”. In such films, uneven thickness and microdefects are noticeable. Their main purpose is product packaging.
Little better are reinforced materials, which are made by hot pressing a film onto a mesh of twisted thread. In production, such films are injured by mesh nodes, and as a result, the low vapor barrier properties are further reduced. Although the film itself turns out to be much stronger than usual, of course.
More reliable are bag fabrics made from polypropylene threads and spunbonds. The former are additionally laminated with molten PEPN, but a uniform and continuous film is still not obtained, although the strength is pleasing. And the latter are made from non-woven polypropylene fiber, but its vapor permeability is still in the range of 15-25 g/m2 per day, and this is a very low figure.
And aluminum foil boasts the best vapor barrier properties, which is even suitable for arranging steam rooms in which the pressure and volume of water vapor are the highest. The only point: such a vapor barrier additionally creates the effect of a thermos in the attic, simultaneously reflecting invisible heat rays back into the room. That’s why it’s better not to insulate a small attic room this way, but for a spacious one it’s just the same.
Therefore, if you want to save heat as much as possible, or you are planning to make a good sauna in the attic, then you need the following vapor barrier:
Or immediately purchase insulation with an aluminum side:
We close access to water vapor
But remember that it is still important to properly lay and waterproof a good vapor barrier film, otherwise water vapor will still find its way in.
The joints of vapor barrier sheets are usually sealed with a special adhesive tape made of butyl rubber, but even in this case complete tightness cannot be guaranteed. The thing is that over time, the adhesion of the sticky layer decreases, and with additional load the canvases come unglued. That is why, when installing exterior finishing, when the same drywall can be attached directly to a vapor barrier, many people install additional sheathing. Its task is not so much to ensure that the finish is fixed more evenly (which is also important), but rather to press the tape or sealant with the slats.
In addition, this sheathing (usually with slats up to 3 cm thick) additionally allows you to lay electrical wires directly under the sheathing, and not through the insulation, as many do and which can hardly be called a technically competent solution.
But the places where the vapor barrier adjoins passing pipes and brick walls must be insulated with special sealants or tapes.
Another important point: never tighten the vapor barrier - fasten it with a small margin. The fact is that all wooden structures, which is what the rafter system is, naturally dry out and become slightly smaller in size. The frame itself becomes mobile, and there is a risk of ruptures under the roof outside and under the sheathing inside. And then - surprise!
Does external waterproofing “breathe”?
So, on the warm inner side of the insulation we install a vapor barrier, which does not allow moist air to enter from the room. And on the outer, colder side we are already attaching waterproofing, which will protect the insulation under the roofing pie from external accidental leaks of melt water or rain.
AND further development events already depends on how “breathable” the top waterproofing film turns out to be. So, if you purchased the most ordinary roll of inexpensive waterproofing, things are bad, the moisture from the roofing cake will evaporate for a long time and difficultly, as a result - dampness and gradual destruction of the insulation. But modern vapor-permeable membranes are called “smart” for a reason: they do not let moisture in, but remove water vapor out. It's all about their unusual, well-thought-out structure. This is why it turns out that when using cheap barrier films, even expensive insulation does not last long, and repairs are not far off.
Please note that the diffuse membrane should fit as tightly as possible to the insulation, without any gap, like with a regular film. Otherwise, the membrane material will cool more strongly, and the temperature will become lower than the steam migrating through the insulation. You will see the result in the form of ice directly on the membrane, which will cause it to lose its vapor-permeable properties even more.
When do you have to dismantle the roof?
Quite often during the construction process, roofing material or reinforced films are installed as roof waterproofing. And after a couple of years, when the attic turned out to be very necessary and everyone at home enthusiastically began to repair it, it turns out that without a complete dismantling of the roof, nothing will work out.
What's the matter? The fact is that such waterproofing does not “breathe” at all, and any insulation under it will completely bend. That’s why, if the roof of your house is still under construction, but you are thinking about putting off insulating the attic for the future, immediately use a good super-diffuse membrane as waterproofing.
But how can something get into the insulation if we have already installed a vapor barrier? The fact is that not a single film in the world is capable of retaining water vapor 100% - they are very small. And no matter how hard manufacturers try, there is no absolute barrier. And even more: modern vapor barrier films actually don’t even do their job halfway, and only the highest quality ones are capable of retaining steam by 75-80%. Everything else, unfortunately, penetrates inside the roofing pie.
Let's sum it up ogi. You should end up with a roofing pie with two films that have absolutely opposite properties: the inner one does not let steam into the insulation, and the second one saves it from a small amount that accidentally gets there.
Insulation of complex structural elements
If you have decided on insulation and insulation materials, congratulations! Prepare everything carefully, calculate everything you need and feel free to proceed. The main thing is to carry out installation work only in a well-ventilated area. And finally, when working with modern insulation materials, many manufacturers advise using a vacuum cleaner before insulating the attic roof from the inside, and after it is finished.
Insulating pitched and straight attic walls is not difficult, and the first difficulty you will encounter is windows and other complex structural elements. It is also important to properly insulate them, leaving no chance for moisture or water vapor to leak through. Do you know what are usually the most problematic places in attic rooms that cause mold and smudges? So take this issue seriously:
Here is another tricky moment when the attic ceiling is not made of logs, but a solid slab. You need to insulate it like this:
And finally, after insulating the attic, make sure that snow does not accumulate later in the drains and on the ridge - the entrance and exit of the movement of under-roof air. To do this, it is more rational to install ventilation pipes along the entire roof ridge, and make the ridge itself unventilated. That's all the difficulties!
Insulation of the attic in the house is mandatory, regardless of whether it is used as a living space or not. Firstly, insulation will avoid significant heat loss from the building. This will help save fuel when heating rooms. Secondly, air humidity decreases, which creates a favorable microclimate for humans, but not suitable for the proliferation of mold and mildew spores. The accumulation of condensation on wooden rafters causes them to rot, which does not have a favorable effect on the condition of the roof. Therefore, proper insulation of the attic is the key to the durability of the structure and a comfortable atmosphere inside the building.
Necessary tools and materials for work
Insulation
There is a wide selection of insulating materials:
- Styrofoam: cheap, affordable, easy to use heat insulator. The disadvantages of this material include toxicity and increased fire hazard.
Polystyrene foam is one of the methods of traditional attic insulation. It is often used to insulate non-residential attics.
- Expanded polystyrene: economical material. Not as flammable as polystyrene foam, non-toxic.
Foamed polystyrene foam is a reliable vapor-permeable insulation. It is not afraid of high humidity, has a dense structure, and low thermal conductivity.
- Mineral wool: lightweight, durable heat insulator.
The material is highly resistant to moisture, easy to install, and absorbs sounds well. Mineral wool is environmentally friendly and resistant to damage, including from rodents.
- Foamed polyurethane: modern material for insulation of premises. The heat insulator is applied with special equipment, filling every crack and gap.
Despite the high price, the material is popular due to its long service life (30 years), strength, and resistance to harmful factors. It will take only 2-3 hours to apply polyurethane.
- Glass wool: cheap but effective heat insulator. Glass wool is resistant to combustion and does not emit toxic substances. However, when working with it, observe safety precautions, since dust from glass wool can harm your health.
You need to protect yourself when working with glass wool by special means: wear a respirator, gloves, suit.
The following materials will also be required for work:
- Before insulating the attic, wooden floors, and other roof elements, treat antiseptic and fire retardants.
- Waterproofing.
- Vapor barrier.
To lay the vapor barrier layer, a special film is used - with a smooth or membrane, perforated surface. It will protect the insulation from settling of water vapor penetrating from the interior.
- Lining, fiberboard sheets, chipboard for finishing.
- For laying some types of insulation, for example, foam, it is used polyurethane foam.
- Timber or boards for the construction of sheathing over insulation.
The sheathing creates a ventilated gap and serves as the basis for fastening finishing materials - sheets of plywood, fiberboard, chipboard.
- Fasteners: staples for a construction stapler, which are used to fasten the film; self-tapping screws for fixing wooden blocks.
Tools you will need:
- construction stapler;
- hacksaw;
- spray foam gun;
- screwdriver;
- hammer;
- drill.
Preparing for work
Before insulating the attic from the inside, check the condition of the rafter system. If it does not meet regulatory safety requirements, it will be necessary to install additional rafters and steel elements to strengthen the structure.
When starting work on insulation, you will waterproof the roof and install air ducts if they did not exist. Their installation will help improve the ventilation system on the roof.
In preparation for work, the floor covering, if there was one in the attic, is removed, then the entire room should be thoroughly dedusted. Protect areas where electrical cables or components of electrical appliances pass with special screens so that after insulation there is free access to them.
Safety precautions
During work, the smallest particles of insulation and other dust can settle on the skin and enter the lungs. This is especially dangerous if the attic is insulated with glass wool. Therefore, during work it is important to follow several safety rules:
- To remove debris, use only a vacuum cleaner for construction purposes.
- Ensure good ventilation during work - open the doors and windows in the attic wide.
- Unpack thermal insulation materials directly at the work site.
- Do not cut the material, but use only a sharp fine-toothed hacksaw or knife.
- When carrying out insulation work, use protective equipment for the skin, eyes, respiratory organs, as well as a special protective suit.
- Avoid direct contact of insulation with skin.
- After finishing work, wash your clothes and take a shower. After working with glass wool, in most cases, you will have to get rid of gloves and clothing.
If you do the insulation of the attic from the inside with your own hands using mineral wool, also use a thick protective suit, goggles and a respirator.
Waterproofing and vapor barrier
The outside of the roof must have good waterproofing, otherwise moisture from precipitation and damp air will easily get inside. This will nullify all efforts at thermal insulation. Water vapor from warm air can settle in the form of dew drops behind the insulation layer under the roof. To prevent this, it is necessary to equip not only internal waterproofing, but also high-quality vapor barrier.
What materials are best used for hydro- and vapor barrier?
It is recommended to use a superdiffuse membrane as waterproofing. It allows excess moisture to pass through, preventing condensation from settling on the insulating material. Place the membrane under the insulation over the entire roof area without causing breaks. A vapor barrier is laid on top of the insulation, for which foil material is often used.
To achieve maximum benefit from this type of vapor barrier, it is laid with a foil layer inside, secured with wooden blocks to provide a gap.
Insulating the attic roof
Guide on how to insulate an attic roof:
Insulation of an attic roof must include ventilation gaps to prevent the occurrence of excessive moisture under the roof. In winter, ventilation gaps prevent heating of the roof covering, and, consequently, the formation of an ice crust. In summer, they help avoid overheating of the living space in the attic.
Floor insulation
The floor in the attic is insulated in the same way as in another room of a wooden house. If there are no beams on the floor, they are sewn on. Then a vapor barrier is laid with an overlap of 15-20 cm. This material will help avoid the formation of condensation from the lower floor. After this, the insulation is installed.
The insulation layer should be at least 15 cm with an overlap of 2 cm. The top of the insulation is covered with another layer of vapor barrier, then sewn up with moisture-resistant plywood. Instead, you can make a sheathing with the installation of a rough flooring made of veneer or edged boards.
Flooring can be laid on top of the beams or decking.
As a result of poor-quality insulation of the floor in the attic, the ceiling of the floor below it may suffer.
Therefore, it is important to maintain a ventilation gap of 5 cm between the vapor barrier layers, and to treat the wooden flooring elements with antiseptics and fire retardants. These products will help increase the service life of the attic floor.
Wall insulation
Insulation of attic walls does not have any significant differences in technology. The process consists of constructing a timber frame, inside which a heat insulator is placed, and then decorative cladding is attached.
Waterproofing is rolled out over the entire area of the attic walls and secured using a construction stapler.
Then a vertical frame made of timber is installed on the walls with a gap equal to the width of the slab or roll of insulation. It is necessary to ensure that there are no gaps between the plates - this will affect the effectiveness of thermal insulation.
The timber is fastened using dowels or metal corners.
Insulation is placed in the resulting cells of the frame. It is recommended to lay it in two layers, especially if foam plastic acts as thermal insulation. A vapor barrier is fixed on top of the frame. The material must be fixed so that there is no sagging. The vapor barrier of the walls and ceiling of the attic must form a single sealed layer, so the joints will need to be taped.
The final stage is covering the surface of the walls with facing material - clapboard, sheets of plasterboard, OSB, which are attached to a wooden frame.
Window insulation
Proper insulation of the attic is impossible without finishing the window openings. Typically, problems with window insulation occur in the area of the upper or lower slopes.
Improper installation of windows can lead to leaks and the formation of gaps for cold air from the street. It is better to order the installation from a specialized company, and do the insulation yourself.
To insulate windows, use only moisture-resistant heat insulators, for example, expanded polystyrene.
The process of insulating roof windows:
Waterproofing slopes: a waterproofing apron is attached around the frame to the sheathing and rafters using a stapler. All joints are sealed with sealant.
There is no need to use polyurethane foam, although most home craftsmen use it. After hardening, the foam expands, causing the pivoting window frame to move relative to the frame. The adjustment of the gaps is disrupted, which subsequently leads to the appearance of cracks, drafts and leaks.
Thermal insulation is installed across the entire width of the window slopes, closing all gaps between the roof and the frame.
If the thickness of the insulation is not enough, condensation may appear on the slopes and the windows may fog up. Such troubles can arise due to cold bridges.
Price of work, calculation of material costs
Do-it-yourself attic insulation is cheaper than work done by specialists. If you don’t have any experience in construction, it’s better not to take risks, but turn to professionals. When ordering a service, you will receive a guarantee for all types of work. The price of the team's services may vary depending on different regions, but it is worth keeping in mind that each stage of the insulation process is paid separately. This is the installation of thermal insulation (on average, from 100 to 300 rubles/sq.m.), waterproofing (from 100 rubles/sq.m.). Separately, the installation of vapor barrier (from 120 rubles/sq.m.), lathing (from 50 to 180 rubles/sq.m.), windows (from 6,000 to 12,000 rubles/piece) is taken into account.
What determines the amount of expenses?
The cost of insulating an attic yourself depends on the price of the material used for heat, hydro and vapor barrier. Costs are also affected by the area of the attic and the complexity of the roof. The cheapest types of insulation are glass wool, its price is on average 60 rubles/sq.m., and polystyrene foam (70 rubles/sq.m.). The price of penoplex starts from 200 rubles/sq.m., but the quality of this material is better than glass wool and polystyrene foam, and it is easier to work with.
When choosing the thickness of insulation, you should take into account the requirements of building codes and climate conditions in a particular region. The quantity is calculated based on the length of all sides of the attic roof and the dimensions of the insulation boards (or the width of the rolls).
After drawing up a diagram of the layout of the slabs, you can accurately determine their required number.
Possible mistakes, what to look out for: 5 useful tips
Do-it-yourself insulation of the attic with your own hands is not always carried out “smoothly”. Here are a few mistakes that DIYers commonly make:
- There are no ventilation gaps between the thermal insulation and the roof of the building. Because of this, the material is not ventilated and does not dry out.
- Hydro- or vapor barriers are not installed.
- The use of polyurethane foam for insulating roof windows.
- Construction of a roof with a slope angle of less than 13 degrees. Such a roof retains precipitation, which causes rust and leaks.
To know how to properly insulate an attic, you should listen to the following advice:
- When installing insulation, leave a gap of 2-3 cm for continuous ventilation. To do this, you can attach additional slats.
- Consider the height of the rafters. If it is less than the thickness of the thermal insulation, bars must be attached to the rafters and screwed onto self-tapping screws. The bars must be treated with an antiseptic.
- Don't forget about installing waterproofing. It will protect the space under the roof from damp air and condensation.
- The vapor barrier must be secured to brackets.
- Carefully seal the junctions of materials with rafters or other structures with tape.
Videos about attic insulation
Basic rules for attic insulation:
How to eliminate condensation in the attic:
Proper insulation of the attic will help create a comfortable atmosphere inside this living space. This will have a positive effect on the roof structure as a whole. In addition, the condition of the rooms located under the attic will depend on the work performed correctly.
The roof is one of the most important structural elements of a building. It is exposed to a variety of environmental factors. Protects the house from high and low temperatures, precipitation, solar radiation. If the roof is not insulated in accordance with building codes, heat loss through the roof can reach a third of the total heat loss of the house. Insulating an attic roof is not as simple a process as it might seem, although it can be done with your own hands. If your house has an attic floor, the question will inevitably arise of how to insulate the attic roof. Many owners prefer to make an additional room there. Firstly, it increases the total living space of the house. And secondly, a new original premises appears. When constructing modern cottage villages, attic spaces are planned initially. But even in old houses, you can easily convert the attic into a living space with your own hands.
The insulating material used for the attic roof, in addition to preserving heat in the house, protects against acoustic vibrations. Therefore, it is important to decide how best to insulate the attic roof.
First you need to decide how to insulate the roof of your attic. Today there are many options for thermal insulation materials. They are easy to install yourself.
Thermal insulation should help maintain a favorable atmosphere in the room. The house should remain warm in winter and cool in summer.
There are many nuances in installing the roof itself. The walls of the attic space are either the gables of the building or the roof slopes, or are adjacent to the slopes. This is why intense air movement begins through the roof. Because of this, it is constantly exposed to temperature changes. To avoid the above problem, insulation of the attic must be done in sequence (from the inner layer to the outer layer):
- Vapor barrier layer.
- Thermal insulating layer.
- Ventilation gap.
- Waterproofing layer.
- Directly roofing material.
If high-quality insulation of the attic roof is carried out, then the absence of the above layers is not recommended. It is especially worth noting the roles of the heat-insulating layer and the ventilation gap. It is thanks to the presence of all the layers that the microclimate in the attic is ensured.
What to look for when choosing insulation
When choosing insulation, you should first look at the thermal conductivity. This is the ability to transfer and absorb heat between the attic space and the surrounding air. A material with low thermal conductivity is desirable. Firstly, this will help better protect the house from heat leaks. And secondly, you will need a thin layer of heat-insulating material.
Properly insulated attic
On the other hand, if the attic roof is insufficiently insulated, problems begin in winter. During the winter months the roof is covered with a layer of snow. Snow is a good additional heat-insulating layer. But with insufficient insulation with your own hands, heat is lost through the roof. The snow is gradually melting. A layer of ice forms. Ice cannot retain heat. It has a mechanical effect on structures. Including the outer roof covering. This leads to its wear and gradual destruction. Sometimes this makes it necessary to repair the outer roofing layer after each winter. With sufficient thermal insulation, snow does not melt in winter and does not turn into ice. The roof retains its structure, and the snow provides additional protection against heat loss. In summer the situation is reversed. When exposed to direct solar radiation, the roof tends to heat up and creates a suffocating atmosphere. If you lay a sufficient layer of insulation, this problem will not exist and a comfortable environment will be provided in the attic.
Main characteristics of insulation
When deciding how to insulate the attic roof of a house from the inside, in addition to thermal conductivity, you need to pay attention to several more important parameters of the insulating material. The most important characteristics:
- water resistance;
- weight;
- fire safety;
- durability;
- material thickness;
- environmental characteristics;
- service life.
Resistance to moisture is usually specified by the manufacturer of a particular material. This is an important parameter, since the roof can leak and get wet. Therefore, it is advisable to choose a material with water-repellent properties. If this is not available for one reason or another, then the layer will have to be additionally waterproofed. Also has great importance weight of material. The smaller it is, the better. The total weight of the material is determined based on its relative density. Mineral wool materials should have a density of 45 to 50 kg/cubic meter. When using fiberglass, the density should be within 20 kg/m3. Heavier materials will place excessive pressure on structures.
Insulating layers must be non-flammable. This is usually reflected in the technical documentation. As for durability, the ability of insulation to retain its shape for many years is important. After all, the roof can be multi-slope. If the insulation is deformed, the roof will simply lose its protective properties.
What materials are popular?
It is necessary to disassemble each one separately to decide how to properly insulate the attic roof. Basic materials:
- Styrofoam;
- extruded polystyrene foam;
- polyurethane foam;
- mineral wool;
- glass wool
The best way to insulate an attic roof is up to you to decide. But before that, you need to familiarize yourself with each material.
Styrofoam- this is a popular material among people who are faced with the problem of how to properly insulate an attic roof. It has suitable thermal conductivity, low density and, accordingly, low weight. Polystyrene foam provides good protection from water and is quite inexpensive. On the other hand, it has certain disadvantages. Its main disadvantage is insufficient fire safety. Also, when installing it yourself, it often crumbles. As a result, gaps appear between the rafters. This in turn leads to a decrease in the thermal insulation characteristics of the coating. Foam plastic also has a short service life.
Extruded polystyrene foam has the best characteristics. Firstly, it is non-flammable and provides the necessary fire safety. Doesn't crumble over time. Has water-repellent properties. Another advantage is that a very thin layer of material is required. The material is not recommended for insulation of residential premises.
Polyurethane foam differs from previous options in the way of installation. Thanks to this, there are no gaps left. The material retains its shape perfectly. It has the necessary fire safety and repels moisture. The disadvantage of polyurethane foam is its poor ability to pass vapors. Because of this, there may be high humidity in the attic space. The problem can be solved by organizing adequate ventilation.
Mineral wool and glass wool widely known as insulating materials. They have many advantages. Excellent fire safety, retain heat well, have low density. They do not leave cracks or gaps during installation. The material provides excellent sound insulation and has a low price. The disadvantages include high moisture absorption and vapor absorption.
Important: installation of glass wool is carried out in closed clothing, a mask and gloves. Contact of material particles with skin and mucous membranes should be avoided.
Laying insulating material
When insulating the attic, do not forget about hydro- and vapor barrier
After selecting the material, it is necessary to prepare the room for installation. Insulation of the attic roof begins with determining the step of laying the insulation. We must try to ensure that the insulation sheets fit tightly between the roof rafters. This will avoid the formation of gaps and further heat loss. If you use foam, then this nuance does not matter to you. The waterproofing is laid overlapped between the rafters and the sheathing. Wooden panels are then installed using screws to provide ventilation. The insulating material itself is mounted directly on the created platform between the rafters.
Tip: the rafters themselves allow heat to pass through. It is necessary to lay an additional thin layer of insulating material on top. Be sure to remember the location of the rafters.
This will be useful when attaching various structures in the attic.
Video: brief summary of proper thermal insulation with mineral wool insulation
Thus, insulating the roof is not difficult at all. To do this, you need to choose the right material that suits you. And then, in accordance with the technology, install the insulation. As a result, a favorable climate for living will be created in the attic room.
