When choosing the best way to insulate a roof, it is important to take into account not only the cost of the material itself, its technical parameters, but also the installation features. You can install many types of heat insulator yourself, but in some cases the use of special equipment is required.
Principles for choosing insulation
To choose the right insulation for your roof, you should first pay attention to the type of roof. It can be flat or pitched - depending on the design features, some requirements for the material differ.
In general, when selecting a heat insulator for a roof, the following parameters are assessed:
- thermal conductivity (the lower this parameter, the more effective the insulation);
- moisture resistance;
- long service life without loss of performance properties;
- stability of shape (material capable of maintaining geometric parameters is more reliable);
- specific gravity (preference is recommended to be given to materials with low density that do not weigh down the roof structure);
- frost resistance (with temperature changes, the thermal insulation material should not lose its properties);
- sound insulation (this parameter is one of the key ones when choosing insulation for a roof covered with a “noisy” roofing material);
- fire resistance;
- environmental friendliness (the material should not emit toxic substances).
The best insulation for roofing is a lightweight, non-flammable, safe and durable material that is suitable for the design of the roof frame.
Errors that significantly affect the quality and reliability of roof insulation include:
- savings on quality (it is recommended to use insulation from reputable manufacturers);
- installation of a heat-insulating layer that is not thick enough;
- violation of installation technology (insufficiently high-quality waterproofing and vapor barrier, the presence of joints and through seams in the insulation layer, lack of ventilation gaps in the pitched roof pie).
Today on the construction market you can find a wide range of thermal insulation materials for roofing. First of all, these are materials:
- slab;
- roll;
- bulk;
- sprayed.
Each type of insulation has its own advantages and disadvantages.
Mineral wool
Roof insulation with mineral wool is today one of the most popular thermal insulation options for flat and pitched roofs. This insulation has a fibrous structure and is made from rock melts. Mineral wool is supplied to the market in the form of rolls or slabs (mats).
When choosing this insulation, you need to carefully consider the thickness and density of the material.
The advantages of mineral wool include:
- high level of thermal insulation;
- affordable price;
- non-flammability;
- environmental safety;
- ease of installation;
- biostability (does not rot, is not damaged by rodents, insects and microorganisms);
- vapor permeability;
- soundproofing;
- stability of geometric dimensions.
Rigid basalt slabs made of mineral fiber are used for external insulation of flat roofs. Mineral wool of less thickness and density is suitable for insulating pitched roofs. Stone wool acts as one of the fire protection elements of the roofing system.
Insulating a roof with mineral wool requires a careful approach to ensuring reliable hydro- and vapor barrier of the heat-insulating layer and creating ventilation gaps. This avoids moisture accumulation in the insulation. Otherwise, the thermal insulation properties of mineral wool will deteriorate, and the rafter structures may begin to rot.
Glass wool
Glass wool is a time-tested thermal insulation material, similar in its characteristics to mineral wool. Melted glass is used to make it. Glass wool is available in rolls and slabs. This is a non-flammable, environmentally friendly insulation with soundproofing properties.
When installing glass wool thermal insulation, it is necessary to use protective equipment and follow certain installation rules to avoid health hazards.
Before insulating a roof with mineral wool, you need to select a material to create a vapor barrier, while a number of manufacturers produce glass wool slabs with a foil coating on the outside. This speeds up and simplifies the installation of this thermal insulation material.
Expanded polystyrene
Extruded polystyrene foam (foam) is a popular board material that is used for roof insulation. It is characterized by high thermal insulation characteristics and is resistant to moisture. Due to the fact that polystyrene foam does not absorb vapors, the slabs can be mounted directly on the waterproofing without creating an air gap in the pitched roof.
The flammability of polystyrene foam and its vapor permeability make this roof insulation material unsuitable for installing flat soft roofs.
When insulating a pitched roof, foam slabs are laid between the rafters in one layer. It is necessary to ensure that the edges of the slabs fit snugly against the wooden structures. The joints must be filled with polyurethane foam, and reinforced tape must be glued on top.
Polyurethane foam
- low thermal conductivity;
- low specific gravity;
- soundproofing properties;
- biostability;
- waterproofing properties (due to the clogged cell structure).
Polyurethane foam is produced in the form of rigid slabs, and can also be applied to the roof structure by spraying.
PPU slabs have sufficient rigidity. They are easy to cut and drill and do not lose their shape during use. Their installation is carried out using the same technology as thermal insulation of the roof with slabs of extruded polystyrene foam.
Spraying polyurethane foam is a modern technology that has already earned recognition. The application of the insulating layer is carried out using special equipment, and this is the main disadvantage of this material. The main advantage of sprayed polyurethane foam is the ability to create a monolithic heat-insulating layer, since the foaming material fills all the cracks.
Penoizol
Roof insulation with foam insulation is similar to using sprayed polyurethane foam. In terms of its technical characteristics, penoizol (urea-formaldehyde foam) is close to conventional polystyrene foam. The advantages of the material include the combination of its price and quality. Taking into account the thermal conductivity coefficient, the cost of penoizol is lower than mineral wool, basalt slabs, and extruded polystyrene foam. The polymer material is safe for human health.
Spraying of penoizol is carried out using a foaming unit. The hose approaches the installation site of the insulation, and the foam fills the required gap. Thermofen in its frozen form is a material that does not weigh down structures and does not have any harmful effects on them.
Penoizol differs from sprayed polystyrene foam in its higher level of moisture absorption, which is about 5%. Therefore, there is a need to install a vapor barrier.
Foam concrete
When installing a flat roof, various materials are used to insulate the roof of the house. These include foam concrete, consisting of:
- concrete;
- cement;
- sand;
- blowing agent.
Foam material allows you to create durable and reliable roof insulation. Due to its low density, foam concrete does not create high loads on supporting structures and retains heat well. The advantages of the material include:
- vapor permeability;
- non-toxic;
- fire safety.
For the installation of foam concrete, a special mobile installation is used. The insulation layer can be from 30 to 150 mm.
Expanded clay
This material is also used when installing flat roofs. Expanded clay is a bulk insulation material that is laid on the floor slab or the outer surface of the roof. The material must be compacted and covered with a screed, while maintaining the required angle of the roof slope to ensure the removal of precipitation.
The use of expanded clay leads to a significant increase in loads on building structures and the foundation of the building, which must be foreseen at the design stage. The quality of such insulation largely depends on the correct execution of installation work.
Foam glass
When choosing how to insulate the roof of a private house, you can pay attention to an environmentally friendly material with high thermal insulation characteristics - foam glass. This material is made by foaming glass mass with carbon, it differs:
- resistance to deformation;
- durability;
- biostability;
- resistance to steam and water;
- non-flammability.
Foamed glass is used for thermal insulation of all types of roofing, regardless of the materials from which it is made. When installing insulation, it is important to take into account its low absorbency and use polymer acetate glue to ensure high adhesion.
The use of foam glass allows you to add elasticity to a soft roof and level its surface. This is a suitable material for arranging flat roofs in use.
Ecowool
Ecowool (cellulose) is an insulation material made from waste paper. This is an environmentally friendly material that has excellent heat-insulating and sound-proofing qualities. To avoid such disadvantages of cellulose as flammability and susceptibility to damage from rodents and microorganisms, ecowool is treated with fire retardants and bioprotective compounds.
Ecowool is a lightweight and cheap material. But insulating a roof with ecowool requires a special approach when it comes to installing a heat insulator between the rafters. Closed “boxes” should be created from slab materials, into which ecowool is blown, completely filling all the cracks. The disadvantages of this insulation include the need for special preparation for installation and the use of specialized equipment.
Sawdust
Roof insulation with sawdust was popular before the advent of modern high-tech materials. Wood processing waste is an environmentally friendly, hypoallergenic, breathable, but flammable material, which must be taken into account when choosing a heat insulator. In addition, sawdust is susceptible to rotting and can serve as a habitat for rodents.
Using bulk material such as sawdust, it is not the roof structure of the house that is insulated, but the ceiling. Ecowool can be used in the same way. A uniform layer of sawdust allows for high-quality insulation of the ceiling of residential premises. To improve the thermal insulation properties, sawdust can be mixed with clay and treated with the attic floor.
The use of sawdust is possible only if the attic space is not in use.
The correct choice of insulation and high-quality installation of the roofing pie will allow you to provide a healthy microclimate in your home all year round, and save on heating in winter.
No matter how modern and high-tech the heating system of a house is, it will not help to survive the frost if the roof of the building is poorly, incorrectly or not at all insulated. Scientists have calculated that it is through the roof that up to 30 percent of the thermal energy is lost if the insulation is not properly insulated. And this is an extra expense for the owner of the premises. How to avoid them? Insulate the roof. The process can be organized independently without involving specialists. The main thing is to choose the material, prepare the tools, and study the sequence of work.
Types of insulation for roofing
Obviously, to insulate the roof you need direct insulation. In order to perfectly fulfill your “professional duties”, namely, to protect the room from the cold, the insulation must meet the following requirements:
- rigidity. The material should not be too soft or pliable, otherwise it will not stay in the chosen place, but will move down or sag;
- low water absorption capacity. If the material absorbs moisture well, it will swell quickly. There can be no question that the room will be comfortable;
- low vapor permeability. Everything here is the same as in the case of water absorption. If matter absorbs steam, it swells and, accordingly, becomes unsuitable for further use;
- relatively light weight. Too heavy insulation means additional load on the walls and foundation. If this load was not taken into account when calculating the roof, problems with the operation of the building may arise;
- self-extinguishing ability or non-flammability. If the roof catches fire, the flames will quickly “eat” the entire building. That is why it is so important to pay special attention to the non-flammability of the selected substance;
- good sound insulation. When, for example, rain hits a roof covering, the sound can be very loud. It can disturb the peace of all residents of the building. To avoid such troubles, the insulation must effectively absorb noise.
It would be good if the material was also environmentally friendly. Then you won’t have to worry about the health of your household once again.
Today all insulation is divided into:
- tiled;
- roll;
- sprayable.
The right to choose, of course, remains with the owner of the premises. WITHThe first two types are easier to work with, while the third is considered more reliable, but difficult to use. To spray, you must master the application technique using a pump or a special sprayer.
There are insulation materials that do not need to be laid, but sprayed inside the rafter frame
The most suitable for roof insulation are:
- fiberglass;
- basalt wool;
- expanded polystyrene;
- extruded polystyrene foam;
- ecowool;
- cotton;
- foam concrete.
To understand which material to choose, you need to understand in more detail the technical characteristics of each of them.
Fiberglass: cheap and available
Fiberglass is made from recycled and melted glass. It is stretched into fibers and used in construction. The advantages of insulation include:
- cheapness;
- accessibility;
- ease of use;
- low thermal conductivity;
- resistance to water and steam.
You need to work with fiberglass as carefully as possible, it can injure the skin
At the same time, you need to work with fiberglass very carefully. Glass particles that come into contact with the skin can cause microcuts, which can result in serious irritation. It is sometimes very difficult to remove fiberglass from your hands on your own - you will probably have to see a doctor. But if you work carefully, using a protective suit, gloves and goggles, then nothing like this will happen.
Fiberglass loses its shape too quickly, so it is not suitable for long-term insulation.
Basalt wool: keeping up with the times
Basalt wool is based on foamed and molten stone. So there is no doubt about the durability of the coating. The advantages of such insulating material include:
- rigidity;
- resistance to fire and high temperatures;
- ease of use;
- safety;
- environmental cleanliness;
- long-term operation.
Basalt wool is considered a very strong and reliable insulation material, and it is quite easy to use.
Working with basalt wool is easy - it is sold in the form of slabs of different sizes. They are attached to the surface using special glue or ordinary nails. However, the cost per square meter here is not the lowest, so this type of insulation is relatively expensive.
Expanded polystyrene: polystyrene foam in other words
Is it permissible to use polystyrene foam for roof insulation? Disputes on this matter between experienced builders do not subside to this day. Summarizing numerous opinions, we can draw the following conclusion: use is permissible in those regions where there are no too harsh and frosty winters.
Expanded polystyrene for insulation is best used in warm areas where the climate is relatively mild
Expanded polystyrene itself does not absorb water and steam, but is too susceptible to changes due to mechanical stress. Any increased load will render the material unusable. It turns out - money down the drain.
Extruded polystyrene foam: reliability in action
Extruded polystyrene foam is essentially a symbiosis of polystyrene foam with freon or carbon dioxide. The material is really durable - this fact has been repeatedly proven during practical tests.
Extruded polystyrene foam does not burn and is not afraid of high temperatures
It is important that extruded polystyrene foam has the following characteristics:
- reliability;
- strength;
- resistance to external influences;
- durability;
- ease of use;
- low thermal conductivity;
- resistance to water and steam;
- non-flammability;
- resistance to chemical compounds;
- ability to prevent the formation of fungus and mold.
By the way, this insulation is considered environmentally friendly. It does not burn and stays firmly in place. But the price for it is not small. The expenses will be significant.
Ecowool: definitely safe
Even from the name ecowool it is clear that this material is very clean from an environmental point of view. In this regard, it can be used without any fear. Ecowool insulation does not harm the body and the environment. It is often used to insulate roofs, floors, and walls of private houses. It's inexpensive and practical. Plus to everything:
Pure cotton and linen: super eco-friendly
Today, cotton and linen are used extremely rarely for insulation. Only residents of very warm parts of the globe can afford this. The fact is that linen and cotton absorb moisture and steam too well, they quickly lose their shape and do not have the required level of rigidity.
Cotton is an environmentally friendly material, but it absorbs moisture very actively and because of this it loses its shape and collapses
Often linen and cotton are used as additional insulation to the main insulation. Such a system has the right to life and is successfully applied even in the Far North.
Cotton and linen insulation is placed under the main one so that moisture from the outside does not get on them.
Those who think that linen and cotton are cheap will be disappointed. Eco-friendly coatings are quite expensive, but not every building owner can afford them.
Foam concrete: this is strength
Foam concrete and strength are practically synonymous words. Very reliable, strong and resistant to external influences material. In addition, it is famous for:
- low thermal conductivity;
- the ability not to absorb moisture and steam;
- resistant to fire and high temperatures.
One bad thing is that foam concrete weighs a lot. If the installation of such insulation was not provided for at the construction stage of the building, then it is advisable to abandon its use. Otherwise, problems with the foundation and walls may arise.
Foam concrete is very heavy, it greatly increases the load on the walls and foundation
How to choose roof insulation for a private house
The home owner is not limited in the choice of insulation for the roof. Each material has its own characteristics, pros and cons. Of course, a lot depends on how much money the home craftsman has. If finances allow, it is better to choose basalt or extruded polystyrene foam. For a more modest budget, the materials are different - polystyrene foam, fiberglass.
Basalt wool, foam concrete, and expanded polystyrene are in approximately the same price segment. It is important to take into account that foam concrete is quite heavy, and its use cannot always be called reasonable.
When choosing, you need to check the following material capabilities:
- is it capable of absorbing water and steam;
- is it burning?
- Is it capable of self-extinguishing?
- can it give off and absorb heat;
- how it is affected by external loads.
It’s good if the material can be attached to regular foam or nails. This will significantly reduce the costs and workload of the owner of the building.
In some cases, polystyrene foam is applied by spraying. This method is considered innovative, but it is very difficult to do it yourself. To do this, you will have to devote a couple of days to theory, purchase a pump or a special sprayer - this is again an extra expense. Are they planned in the budget?
Spraying polystyrene foam is a rather difficult process, not everyone can do it correctly
It’s good if you have the opportunity to test the insulation in person. Its total thickness must be at least 200 millimeters. Then it will be warm and comfortable under the roof.
If a living room is planned under the roof, then the insulation layer should be thicker than if an attic space is installed under the roof.
Laying rules
The process of roof insulation involves more than simply attaching the material to wooden rafters. This is a complex technological process consisting of the following stages:
- Preparing the surface for work.
- Installation of a waterproofing layer.
- Ventilation device.
- Laying insulation.
- Installation of a vapor barrier layer.
- Laying the top covering on the roof.
To properly install insulation, you must:
- Measure the area to be finished.
- Draw up a rough plan and drawing of insulation. Let it be approximate and sketchy, but it will greatly facilitate the task.
- Make an accurate calculation of the insulation required to complete the task.
What else you need to know in order to install insulation efficiently:
And the most important rule: act slowly and very carefully. This is the only way to properly insulate the roof.
Step-by-step instructions for laying insulation
You can lay insulation in different ways:
- between the rafters;
- under roof cladding;
- in front of the rafters.
Which option is preferable? It all depends on the area of the roof, its general condition and the desire of the master.
To carry out the work you will need:
- the insulation itself;
- waterproofing;
- screws, nails;
- construction stapler;
- polyurethane foam;
- wooden bars for sheathing, 2–3 centimeters wide;
- protective clothing, gloves.
The process of self-insulation of the roof consists of the following steps:
- It is necessary to carefully inspect the roof covering for damage. This is done if you first laid the outer covering and then decided to insulate it. If there are damages, they must be repaired.
Before you start insulating, the roof must be repaired
- Now you need to prepare the rafters for work - sand them, clean them of dirt, and treat them with an antifungal compound.
It is important to pre-treat wooden rafters against fungus and destruction
- Next, a waterproofing layer is laid. Most often, modern membrane waterproofing is used, which has long proven itself positively. It’s great if the insulation is self-adhesive, otherwise it can be secured using a construction stapler.
It’s good if the waterproofing is self-adhesive, it’s very easy to work with.
- Then you need to make a ventilation gap. Otherwise, condensation will accumulate under the roof, and the building will simply be unbearable to operate. The space for ventilation is at least 5 cm. But it should not be more than 15 cm. Counter battens are placed on the waterproofing layer, and the main sheathing and roofing are already attached to it.
The sheathing is mounted on the waterproofing layer and is responsible for creating a ventilation gap
- If the insulation material is attached from the inside, it should be laid in the space between the rafters. It must go joint to joint without any gaps at all, otherwise the insulation will not be normal. The slabs must be installed by surprise, and all resulting irregularities must be coated with foam.
The insulation must be laid joint-to-joint so that there are no gaps between it and the rafters
- A vapor barrier membrane must be laid on top of the insulation. Often intermediate slats are nailed between it and the insulation to create a second ventilation gap. Its presence guarantees complete elimination of possible condensation.
- After this, you can install the finishing coating. To do this, rough sheathing is placed on the rafters, and finishing material is installed on top.
If all layers are made sequentially, the material is attached without gaps, and only high-quality tools and coatings are selected for the work, then no problems should arise during further operation. It is important to always remember your own calculations and drawings and focus on them.
In order for the work to be as efficient as possible, it is important to make at least an approximate drawing indicating the order of work.
In no case should the insulation sag by more than 10 centimeters. If this happens, it means there are problems with the material or installation. Before fastening, any material must be tested for functionality right at home: you can pour water on it, put a small weight on it. If the insulation holds up, it can be safely attached under the roofing cladding material.
Video: how to lay insulation on a roof
To ensure that your home is always warm and comfortable, it is important to take care of high-quality roof insulation. For this, various materials can be used: basalt wool, ecowool, expanded polystyrene and its extruded analogue, linen and cotton, foam concrete. The choice depends on the financial capabilities and preferences of the owner of the building. It is important that the insulation meets all safety requirements and is clean in every sense for people and the environment. If installed correctly, the insulation will last at least 20 years. And foam concrete or basalt - generally all 50!
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Insulating the roof from the inside is the best option for work for several reasons.
Roof insulation is done only for residential attic spaces; due to this, heat losses are significantly reduced and living comfort is increased. Today, companies produce a wide range of insulation materials, all of which have both positive and negative sides. When choosing a specific insulation, it is important to know its features and take into account the characteristics of the building’s rafter system.
There are many names of materials for insulation, but they are all divided into two large groups.
Table. Roof insulation groups.
| Name of insulation | Operational and physical characteristics |
|---|---|
| This group includes mineral wool from basalt, glass wool from recycled glass and ecowool from waste paper. Cotton wool insulation can be pressed in the form of mats of standard sizes or rolled. There are options for spraying liquid ecowool. In terms of thermal conductivity and weight, the listed types hardly differ from each other. Mineral wool is the most expensive. |
| Polystyrene foam, polystyrene foam, polyurethane foam, etc. All these insulation materials are made on the basis of the same polymer and differ in production technology and some additives. Most often they take the form of slabs of various thicknesses and sizes; they can differ significantly in terms of physical strength. Thermal conductivity is almost the same; minor fluctuations in practice have no effect. The price range is wide. Can be used in liquid form (sprayed) or as slabs. |
As an example, we will look at the two most common options for insulating a roof from the inside. The examples are not only budget-friendly, but also effective. The process is divided into several stages, and the final quality of the work depends on the correct execution of each of them.
Prices for foam plastic
Foam plastic
Inspection of the rafter system and roof covering
A very important stage of preparation for insulation. Inspect all elements of the roofing system, check the condition of the roof covering. If problems are discovered, they must be corrected immediately.
Measure the distance between the rafter legs, this will help you navigate the choice of insulation. The point is that all insulation has standard width dimensions. This simplifies and speeds up installation work and reduces waste. The width of the insulation is 60 cm, but, unfortunately, some manufacturers allow fluctuations in one direction or another by several centimeters. The distance between the rafter legs should be within 56–57 cm. In practice, it is rare to find such correct roofs.
See if a wind barrier is installed between the roof and the attic, and if it has vents for natural ventilation. This is very important in cases where insulation is planned to be done with mineral wool.
Prices for vapor barrier materials
Vapor barrier material
Selection and purchase of materials
The most commonly used materials for roof insulation are mineral wool and polystyrene foam; we will dwell on them in detail. If you have a simple gable roof, then insulating it is not very difficult technologically. The situation is completely different with a sloping or hipped roof. These structures have many different stops, purlins, ties and other elements that strengthen the rafter system. During insulation, you have to trim the mineral wool or foam plastic, make various folds and bends. As a result, the complexity of the work increases and the amount of waste increases.
But this is not all the problems. Complex roofs will never be able to be hermetically sealed with a vapor barrier layer; there will always be places through which moist air gets into the insulation. For mineral wool this is a very unpleasant phenomenon. Experienced builders recommend insulating complex roofs with foam plastic rather than taking risks with mineral wool. Wet cotton wool not only almost completely loses its heat-saving abilities, but also accelerates the putrefactive processes of wooden structures of the rafter system.
Roof insulation work
The technology of work largely depends on the chosen material, but for all cases there are general tips.
If you have the opportunity to work with an assistant, great, the insulation process will go much faster. There is no such possibility - no problem, all the work can be done independently.
Without high-quality thermal insulation at home, it will not be possible to save on heating in winter. Walls and floors are not the only ways through which heat leaves a living space. In addition to them, it is also necessary to insulate the roof.
Internal insulation scheme
A kind of pie is a high-quality insulation of the roof from the inside, consisting in almost all cases of three main layers:
- Waterproofing
- Thermal insulation
- Vapor barrier
However, the basis of the entire structure is the rafter system, which will act as a base link. The easiest way is to lay a thermal insulation layer inside it.
Properly selected materials for each layer of the pie are the basis for high-quality insulation. The market is rich in various products, but you should not pay attention only to cheap options, giving preference to the golden mean.
The main purpose of the waterproofing layer is to protect the insulation from moisture from outside. It accumulates inside it, destroys the structure of the material and renders it unusable. The task of the vapor barrier layer is to prevent rising vapors from passing through.
To protect against wet environments, special membrane or film materials are used. The permeability indicators of the former are better, but their market value is more expensive. Since it will not be possible to ensure complete sealing of the insulation, it is necessary to provide ventilation gaps and seams.
Introductory video on insulating a pitched roof in a house
Choosing thermal insulation material
Many manufacturers offer consumers a variety of thermal insulators, each of which has positive and negative sides. Among all operational characteristics, special attention is paid to the following:
- Level of moisture absorption - the lower this ability of the materials in question, the longer their service life can be counted on
- Thermal conductivity – it should be as low as possible. However, this indicator is relative, since an increase in porosity and importance can significantly worsen it
- Low-density insulation materials have much better thermal insulation properties
Video on material selection
You should also pay attention to such characteristics as environmental friendliness, chemical resistance, flammability and frost resistance.
The most widely used materials for insulating roofs from the inside are mineral wool and glass wool. They have all the necessary characteristics and are relatively easy to use.
Expanded polystyrene is no less popular. In addition to high thermal insulation properties, it practically does not absorb moisture, is durable and rigid, resistant to high temperatures and open fire. A significant disadvantage is the susceptibility to rodent infestation. That is why it has not become widespread.
Other, less common methods of internal insulation are also possible:
- The use of spraying is one of the most expensive methods, which is recommended to be entrusted to a professional craftsman. If you need to insulate a conventional attic, you should choose this method. Material costs will be paid off by performance characteristics
- Insulation with liquid compounds (polyurethane foam or foam concrete) is not very popular, as it requires the use of specialized equipment to carry out the work
If thermal insulation of a classic attic space is required, additional insulation is provided above the ceiling (expanded clay, sawdust, sand, etc.).
Let's start insulating the roof with our own hands
The most common case is the insulation of pitched roofs using rolled materials. First of all, you need to draw up instructions for yourself, following which you can count on high quality results. Let's consider the case when the roof has not yet been laid.
First, you need to go through the attic again and make sure that all the components are in perfect order. If defects are found (rotting, cracks, etc.), they should be eliminated immediately.
Sometimes various communication systems are laid on the roof: electrical wiring, heating, water supply, etc. They are also subject to thorough inspection and elimination of defects. Only after order has been established can further work begin.
The first step will be to apply a waterproofing film to the outer surface. In order for it to fulfill its purpose, several rules must be taken into account:
- It is necessary to lay the film across, and at the joints, stripes of about a meter are applied, which are glued with tape.
- It is necessary to select a material for waterproofing only after purchasing insulation so that they match each other’s characteristics
- Under no circumstances should you pull it tightly over the surface. At sub-zero temperatures it will begin to shrink and, as a result, may burst.
Having completed the work with waterproofing, it is necessary to begin arranging the sheathing. For it, beams treated with antiseptic materials with a size of no more than 25 mm are recommended. Corrosion-resistant self-tapping screws are used for fixation
Roofing materials can be attached directly to the sheathing. Things will be a little different with a soft roof. It is recommended to place moisture-resistant plasterboard or chipboard between it and the wood.
The next stage is laying thermal insulation material into the gaps between the rafters. It is recommended to adjust the slabs to the width between the rafter opening; the mats are cut into pieces equal to each other.
The material is laid in such a way that there are no gaps between the elements. It should also not be pressed very tightly to the roof so that there is a ventilation gap.
Another feature is the laying of thermal insulation material not in one, but in two layers. At the same time, they are positioned relative to each other with an offset so that the through joints are closed.
Having finished laying the insulation, you can proceed to the next stage - tensioning and fastening the vapor barrier film or membrane. It is recommended to nail it to the rafters with staples. It, unlike waterproofing, is stretched much tighter.
Next, you can proceed to the final stage of insulating the roof from the inside - interior finishing. A wooden frame is placed on top of the vapor barrier film, to which the desired finishing material will be attached.
Video on thermal insulation using polyurethane foam
Some useful tips
When insulating a roof from the inside, not everything can go as smoothly as it seems at first. In addition, any rafter system has its own characteristics.
We list a number of rules that may be useful when performing roof insulation work:
- Particular attention to waterproofing and vapor barrier must be paid when working with mineral insulation. They are most susceptible to the accumulation of moisture inside, causing destructive effects.
- Sometimes, for a light roof, the roof truss system is built from timber of a small cross-section. In this case, you will have to use a combined method of thermal insulation, placing the material not only between the beams, but also under them
- When the pitch of the rafter system is too large, the insulation is additionally fixed with wire, which is pulled between the screws screwed into the rafters
- To ensure that the insulation is not tightly located between the rafters, its width must be greater than the similar characteristic of the openings
- You should not make too many layers of insulation. For example, for thermal insulation with a thickness of 20 cm, two layers of 10 cm each will be better than four layers of 5 cm each.
- The insulation can be placed close to the super diffusion membrane. In all other cases it is necessary to leave a ventilation gap
- It is necessary to monitor ventilation gaps, which should not be blocked by thermal insulation material
In conclusion
Absolutely everyone can make high-quality insulation of the roof from the inside, which will serve for decades, reliably retaining heat and keeping out the cold. However, for those who do not want to waste their time and energy, professionals offer their services. The cost of work can vary between 5-25 USD. e. per square.
Heat loss in the cold season, 15–20% of total heat loss reaches through the roof.
This means that if the floor and walls are well insulated, but the ceiling or roof is not insulated, then with total heating consumption 2000 kg of coal per season, 300-400 kg is spent on heating the street.
Thus, with an insulated roof, it will be possible to buy 1600–1700 kg of coal per season instead of two tons.
However, saving money doesn't stop there. Roof without thermal insulation heated by warm air from below. Snow falling on a warm roof melts and sticks to it in a thick layer. This increases the stress on the roofing material and can lead to damage. During a thaw, a layer of snow melts from below and slides off the pitched roof, damaging the drainage system.
Roof with good thermal insulation stays cold. Dry snow is blown away from it by the wind, practically without stopping. There are almost no icicles on the edges of such a roof.
Obviously, the difference is significant enough to consider insulating the roof. This kind of work does not require high qualifications, so with certain knowledge and skills you can do it yourself.
You can insulate the roof from heat from below during its installation. This is what they usually do now. Work in this case are carried out from above in this order:
- A vapor barrier membrane is attached to the lower surfaces of the rafters. To do this, the panels are unfolded and, slightly stretched, stapled with a stapler. Work begins at the bottom of the rafters and ends at the ridge. The panels overlap at the joints, gluing the edges with construction tape.
- From below, the vapor barrier film is nailed to the rafters with bars with a cross-section of 30×40 mm across the rafters in increments of 30–40 cm. This lathing will hold the insulation, and the finishing material is attached to it from below.
- Insulation boards are laid on top between the rafters to the level of the top edge.
- When the slabs of heat-insulating material are level with the upper edge of the rafters, they are covered with panels of waterproofing, vapor-permeable material. This hydrobarrier is secured with staples using a stapler in the same way as a vapor barrier with an overlap of 15 cm.
- A sheathing is constructed on top of the hydrobarrier, onto which the roofing material is secured.
However, for one reason or another, insulating materials are not always installed together with the roof. In this case the roof have to insulate later. The same is done in old houses after renovation.
Do-it-yourself insulation of a finished roof in a private house
Laying thermal insulation into an already constructed roof happens in reverse order. If the insulation “pie” during construction is formed from above, then the finished roof is insulated from below.
Before work starts need to find out how well the roof is installed.
In an old house need to check strength of rafters and floor beams. Rotten load-bearing elements are replaced with new ones, treated with preparations that protect against rotting and fire. After this, they begin laying thermal insulation:
- After measuring the thickness of the rafters and the distance between them, the sheets of thermal insulation material are cut with a slight excess in width (about 1–2 cm). This is necessary so that the elastic plates fit into place tightly, without gaps.
- A hydraulic barrier is needed between the roof and the insulation, protecting against water drops but allowing steam to pass through. If the roof is new and was installed according to all the rules, you will not have to lay it. Otherwise, you will have to purchase waterproofing. The best candidates for this role are the so-called superdiffusion membranes, do not allow liquid water to pass through, but at high air humidity they allow water vapor to pass through. This material is laid without undue tension and secured with a stapler to the rafters, and in the spaces between them - to the roof sheathing. The panels at the joints are secured with an overlap of 15 cm, gluing one panel to another with construction tape.
- Cut slabs of thermal insulation material are inserted between the rafters, pressing them against the membrane. All cracks that arise are sealed with construction foam. It is preferable to lay the slabs in two layers, overlapping the joint of the previous layer with the slab of the next one. After completing this stage, the level of the slabs should be equal to the inner end of the rafters.
- Along the inner end of the rafters it is stretched and secured with a stapler. The panels are unfolded horizontally and laid from bottom to top with overlapping edges of adjacent panels 15 cm wide. The edges are glued with construction tape.
- On top of the film, at right angles to the rafters, sheathing bars with a cross-section of 30×40 mm are stuffed in increments of 30–40 cm. The lining or fiberboard slabs will be attached to them. After completion of the work, a ventilation gap is formed between the vapor barrier film and the finishing to evaporate possible condensation.
- The more carefully the vapor barrier is laid, the better the insulation retains heat.
Flat roof insulation
Flat roof too can be insulated. However, in this case there is no attic. External insulation of such a roof is done during the process of laying the roof. A vapor barrier film is glued to the floor slab.
Insulation is laid on top of this film. Best suitable for these purposes. After laying, the top of the stone wool is covered with roofing felt, which serves as a vapor-permeable waterproofing.
So that you can walk on the roof, without damaging the roofing material, the covering is done in the same way as on the sidewalk. To do this, a layer of expanded clay is poured onto the roofing felt, then a cement-sand mixture, on which paving slabs are laid. After getting wet in the rain, the cement-sand mixture sets and holds the tile.
Expanded clay underneath plays the role of drainage. There are no ventilation layers in such a roof. Internal insulation of a flat roof is done using the technology of internal thermal insulation of the ceiling.
So that living conditions in winter are quite comfortable, it is necessary to ensure a certain level of thermal insulation of the room. This level is determined by heat transfer resistance. It does not matter how many layers and what kind of heat-insulating material are laid.
You can read about how to calculate the required insulation thickness in the article “”. If you correctly lay thermal insulation materials when installing the roof, you can save 15–20% energy, spent on heating a private house.
The technology of roof insulation is simple. Any home handyman can handle it subject to technology. You can insulate the roof during the installation of the roof and after it. However, the technology for carrying out such work will be different.
For detailed instructions from ISOVER on how to insulate a roof in a private house with your own hands, watch the video: