Styrofoam
Polyfoam is a modern heat-insulating material based on expanded polystyrene. In its structure, it is a hardened expanded polystyrene, inside of which there are many air bubbles.
The advantages of foam plastic are light weight, excellent thermal insulation characteristics, low hygroscopicity and good soundproofing properties, which, combined with affordable cost, make it one of the most preferred materials for insulation. At the same time, the disadvantages of polystyrene, which should be taken into account when arranging the attic, are combustibility, instability to high temperatures and exposure to ultraviolet rays, as well as low strength.
To improve performance, some manufacturers process foam plastic products with fire retardants, which increases their service life by several years, which makes attic insulation with foam plastic cost-effective.
It should also be said about what layer of insulation is needed for the attic if this material is used. Its required thickness for most climatic zones is 15-20 centimeters, but in frosty regions it makes sense to increase it to 25-30 centimeters.
When arranging the thermal insulation of the attic roof from foam, it is important to ensure good ventilation of the under-roof space, since this material is not "breathable". Otherwise, it may lead to condensation, mold and putrefaction.
Which roll material or mats to choose
When choosing a heater for the attic, the question may arise, is it better to roll material or slabs? In this case, the answer for each will be individual, since everyone has different preferences.
Practical experience shows that material in rolls is more convenient to use. It is enough to roll the roll to the desired length and cut off a piece. In addition, when insulating a roof that has a standard distance between the rafters, you can easily cut the material in half and fill the free space with them.
In the case of insulation boards, the advantage is convenient transportation. However, practical application is more problematic, since the plates are rectangular in shape.
In conclusion, it should be recalled that when buying an attic insulation, it is very important to pay attention to the packaging. It should not have scratches or damage, indicating a violation of tightness. Only in this case is guaranteed protection from moisture ingress to the insulation before the start of installation work.
Moisture that has entered the material through poor-quality packaging leads to wetting of the insulation and a change in its shape. As a result, installation is largely difficult, and gaps form between the plates. In addition, damp material becomes a breeding ground for mold and fungus, which spoil the appearance of the surface and become a source of unpleasant odors.
Only in this case is guaranteed protection against moisture ingress to the insulation before the start of installation work. Moisture that has entered the material through poor-quality packaging leads to wetting of the insulation and a change in its shape. As a result, installation is largely difficult, and gaps form between the plates. In addition, damp material becomes a breeding ground for mold and fungus, which spoil the appearance of the surface and become a source of unpleasant odor.
Mineral wool density and thickness of mineral wool
Mineral wool is perhaps the most common insulation for mansard roofs due to its low cost and good thermal insulation qualities.In addition, the advantages of this material are also fire resistance, good air permeability and low hygroscopicity. On the other hand, the thermal insulation characteristics of mineral wool are significantly reduced when wet, which makes it mandatory to equip a waterproofing and vapor barrier membrane for it.
Mineral wool has several varieties:
- glass wool;
- slag;
- basalt, or stone wool.
Glass wool is made from the finest glass fibers with a thickness of 5-15 microns and a length of 15-50 millimeters.
It has an elastic and durable structure, and requires great care in work: in order to avoid irritation, when laying it, put on a protective suit, gloves, goggles and a respirator. Resistant to temperatures from minus 60 to plus 450-500 °C
Slag wool, made from blast-furnace slag, contains fibers 4-12 microns thick and about 16 millimeters long. This material can withstand heating up to 300 ° C, however, it is ineffective in arranging attic thermal insulation due to its high hygroscopicity. In addition, slags with residual acidity can aggressively act on metal surfaces, which is also a significant disadvantage. The disadvantages of slag wool are also its fragility and "pricklyness", which creates inconvenience when working with it with bare hands.
Basalt (stone) wool is made from gabbro-basalt or diabase with composite and binder additives. Its fibers are approximately the same size as those of slag wool. In terms of technological characteristics, this material surpasses all other types of mineral wool, and therefore it is especially often used for thermal insulation of mansard roofs. Stable when heated up to 600 °C (some types - up to 1000 °C). When using this variety, the elasticity and density of mineral wool for attic insulation are sufficient so that the material does not wrinkle and does not settle when mounted on slopes.
As for the required thickness of mineral wool for attic insulation, it largely depends on climatic conditions, averaging 15-30 centimeters. It is clear that in regions with a colder and more humid climate, the thickness of the insulation for the attic roof should be relatively larger.
Polymer heat-insulating materials
In the absence of a waterproofing film or a diffusion membrane that protects the rafters from moisture accumulation during steam condensation, it is best to choose one of the polymer insulation.
Most often, a similar situation develops during the construction of a house in which a residential attic was not supposed to be installed. That is why materials with extremely low permeability, such as polyurethane foams and expanded polystyrene, become the best option.
Such heaters perfectly protect not only from freezing of the structure or lowering the temperature in the room, but also from constant exposure to moisture. They are harmless to humans, but require the creation of ventilation systems, as they interfere with normal air circulation.
Polyurethane foams
An interesting option for thermal insulation of the roof is a material based on polyurethane foam. Such insulation is applied by spraying, which ensures the absolute integrity of its layer without the formation of cold bridges.
In addition, this material does not require additional fastening or fixing due to good adhesion to the base. To process a roof of 100 square meters, it will take no more than 4 - 8 hours, which significantly reduces the process of arranging the attic floor.
The thickness of such insulation to protect the attic compared to classic mineral wool can be reduced by 1.5 - 2 times and is 80 - 100 mm. Thanks to the integral structure of the applied layer, as well as the formation of absolutely closed air cavities, polyurethane foam perfectly protects the room from heat loss.
Styrofoam
In this case, both classic polystyrene foam and extruded polystyrene foam will perfectly cope with the task of warming.
Both materials have excellent thermal insulation properties, but the extruded version is more reliable and durable. Its thermal conductivity is lower, so the effective layer is reduced to 80 mm.
The cost of foam is lower, but given the difference in the amount of materials required, the total costs remain approximately the same. The indisputable advantage of extruded polystyrene foam over polystyrene foam is its incombustibility.
Extruded polystyrene foam, unlike polystyrene, is not affected by rodents, its structure simply does not allow them to create their nests in the thickness of the material. Nevertheless, the foam is still one of the most popular heaters.
The density of both types of expanded polystyrene is also selected in the range of 30 - 50 kg / m3 to prevent the weight of the structure. They are fastened to special dish-shaped dowels with large polymer covers.
Material requirements
Requirements for heaters may differ depending on the type of roofing device, but the basic characteristics should remain unchanged:
- thermal conductivity not more than 0.045 W/mK;
- material density in the range of 30 - 50 kg per cubic meter;
- rigid or semi-rigid structure of the heat insulator.
Thickness
The thickness of the insulation layer directly depends on the purpose of the attic floor. When arranging living rooms and a bathroom within this space, it is necessary to protect the structure as much as possible from heat loss and freezing.
That is why experts advise using a layer of insulation of at least 100 - 150 mm. Moreover, the material is laid in 2 layers for more effective protection against heat loss.
Density
It is also worth remembering that the lower the density of the material, the greater its thermal insulation capacity and the less impact on the truss system. We must not forget that the weighting of the roof can adversely affect the state of the entire structure of the house, because the pressure of the rafters on the walls increases, and this can lead to their deformation.
That is why, before choosing the optimal insulation for the attic, it is necessary to carefully study its properties and calculate the approximate load on the truss system.
Sawdust
Insulation of the attic roof with sawdust is not recommended due to the low performance of this material. The only advantage is the price. According to other criteria, sawdust loses to modern heaters.
- Relatively high coefficient of thermal conductivity;
- Spontaneous change in density under the influence of gravity, the likelihood of voids in the roof structure;
- combustible material. The effect is reduced when using a mortar with gypsum, cement or lime;
- Gives in to rotting;
- Habitat for rodents and insects.
The best material for attic insulation is basalt wool and polyurethane foam. They have high thermal insulation properties, reduce noise levels and are harmless for use in residential areas.
Performance characteristics of fibrous insulation
glass wool. Its positive qualities include:
- fire safety (2nd degree of fire resistance);
- environmental safety (does not contain resins);
- unattractive for mice (do not build nests and moves);
- affordable price.
The main disadvantage is that when working with the material, sharp glass dust is formed, the installation of a heat insulator requires accuracy and the use of protective equipment.. In addition, over time, glass wool tends to deform, wrinkle, especially when moisture penetrates.
Mineral wool. The composition of the material includes fibers of various origins (production material - clay, stone, quartz sand, glass, etc.). Mineral wool is characterized by a multilayer heterogeneous structure with air lenses. Due to this, the material dampens sound waves well. Mineral wool (primarily Isover, Ursa) is recommended for those who decide to make metal roofing.
Such a heat insulator is fire resistant, does not rot, and is easy to install.But rodents can settle in it, whose nests, passages and waste products reduce the performance properties of the insulation.
Basalt wool. Consists of fibers obtained by melting rock. Withstands heat up to 1000 degrees, does not spread combustion. Basalt wool should be chosen carefully, checking quality and safety certificates: some manufacturers, in an effort to reduce the cost of products, use resins that emit toxic substances.
Basalt wool
Basalt wool is resistant to fungus, but can be damaged by rodents. This is a good sound insulator, easy to install. But when choosing a material for insulating the truss system, one should take into account the rather large weight of stone wool slabs.
If you have to choose a fibrous heat insulator for attic insulation, pay attention to the density of the material. The heat insulator should not lose shape even with prolonged use
For mineral, basalt wool, the density index should be about 40-45 kg / m3.
Polymer materials for insulation
We choose a polymer heat insulator for the roof and walls of the attic. This can be foam, extruded polystyrene foam (these two types of insulation are available in the form of sheets and plates of various thicknesses), as well as polyurethane foam, which is applied to structures by spraying.
The advantages of polymer insulation include low weight and low thermal conductivity. Such thermal insulation will not overload the truss system and will successfully cope with the task of retaining heat.
The disadvantages of polymer insulation include extremely low vapor permeability. Gas exchange is not carried out through insulated structures, therefore, one cannot do without a well-thought-out ventilation system in the attic room.
Attic insulation with polyurethane foam
Thermal insulation made of extruded polystyrene (foam) and polyurethane foam will not allow heat and steam to pass to the roof truss frame, therefore, there is no need to install a vapor barrier from the side of the room. Despite the fact that the dew point during the internal insulation of the gables will shift towards the heat insulator, moisture dangerous to wood will not condense.
Manufacturers produce penoplex of various densities. For pitched roofs and attic walls, where heat losses are high, it is advisable to use slabs with a density of 30-35 kg / m3.
A suitable foam density is 35 kg/m3, the material must not crumble into individual balls when broken. Since foam plastic smolders when ignited, releasing toxic substances and mice easily gnaw through it, this is not the best material for internal insulation.
Polymer insulation for the attic should not be considered as a soundproofing material for the roof - it will not save you from the sound of raindrops. But if you insulate the floor with it, it will reduce the vibration load from steps, creating acoustic comfort in the rooms under the attic.
The selected insulation option will last for many years if you purchase good material and take into account all the subtleties of its installation.
The choice of thermal insulation
The design of the attic roof has the following features that you need to focus on when choosing a material for its insulation:
- Lightweight materials should be used as roofing and insulation for a mansard roof, since its design is not designed for increased loads.
- To insulate the mansard roof, the most effective materials should be used so that the thickness of the roofing cake layer is minimal - this will also help reduce the weight of the roof structure.
- It is mandatory to install a ventilation system for the roof space, which provides humidity control in the room.
Mineral wool
Mineral wool is often used to insulate mansard roofs. Her virtues:
- Light weight.
- High thermal insulation qualities.
- Good vapor permeability and sound insulation.
- Environmental friendliness and fire safety.
The amount of insulation corresponds to the area of \u200b\u200bthe roof slopes minus the area of the openings
Among the disadvantages of such thermal insulation of the attic roof are the relatively high price and the tendency to get wet. In addition, mineral wool can become caked over time and lose its properties.
Important: For roof insulation (inclined and vertical surfaces), it is better to use mineral wool in slabs rather than rolls - this will facilitate installation.
You can also use glass wool to insulate the attic roof, but it is less convenient to use and requires protective equipment: gloves, overalls and glasses.
In cold regions, the thickness of such thermal insulation should be 150-200 mm - this can be ensured by laying mineral wool slabs in two layers. With external insulation, work on the installation of the material should be carried out only in dry weather.
Styrofoam or Styrofoam
Insulation of mansard roofs with foam plastic is common due to its low cost. Among the advantages:
- Little weight.
- Low thermal conductivity.
- Ease of processing and installation.
- Good operational qualities.
- Doesn't deform.
- Not afraid of moisture.
How to insulate the roof of the attic with foam
Insulation of the mansard roof with foam plastic has a significant drawback - fire hazard. But you can use extruded polystyrenes, which do not burn, but only melt, but their cost is much higher.
Polyurethane foam (PPU)
A new effective material for attic roof insulation. In fact, it is a modified polyurethane foam. PPU can only be used to insulate a mansard roof from the inside, a video with application technology at the end of the article, but at the same time:
- The thickness of the insulation layer is minimal.
- PPU has good adhesion, and when applied, it fills all the voids in the structures.
- It is simultaneously heat, hydro and vapor barrier.
Insulation with PPU
Spraying polyurethane foam requires special skills and equipment, but there will be no seams at all, which will prevent freezing of structural elements.
When choosing the best way to insulate a mansard roof, you can also focus on material such as ecowool. This natural insulation (made from linen) will not only protect you from the cold, but also from overheating in the heat, is breathable and environmentally friendly. Ecowool provides a seamless coating and does not require a vapor barrier. Suitable, for example, for insulating sloping mansard roofs due to easy installation on inclined surfaces.
A little about the types of heaters
Next, we will consider heaters suitable for insulating the attic floor, its gables and roof. There are a great variety of materials offered to us in stores, and they all have different physical and technical characteristics. Let's figure out which insulation is best for the attic.
Mineral wool
The most popular material for insulating the attic floor is produced by different companies - Rockwool, Ursa, etc. Mineral wool has a low thermal conductivity and absorbs sound well. It is worth mentioning the fire safety of the material: slag wool begins to smolder at 300C °, stone wool at 600C °, and basalt generally only at 1000C °. There is only one significant disadvantage of mineral wool: it gets wet.
It is produced in rolls - soft, and in plates - more rigid, the density is higher. If the attic has a ceiling, we “insulate” it with a rolled rockwool or similar mineral wool from another company. For gables, slab types of mineral wool are better suited: rolled ones, due to their softness, being installed on a vertical surface, will sag over time.
The better to insulate the attic from the inside: mineral wool
Insulation of the attic floor with penofol
The material has good thermal insulation qualities, but foam insulation as an independent material is impossible, it is too thin.But as an additional insulation and replacement of vapor protection, it can be used, however, due to its vapor tightness, it requires good ventilation.
How to properly insulate the attic from the inside: penofol is suitable only as a vapor barrier
Penoplex and polystyrene for insulation of the attic floor
Penoplex and polystyrene are both derivatives of polystyrene. On the insulation of the attic with foam, the reviews are generally not bad. The same applies to penoplex. Both materials perfectly retain heat, almost do not absorb moisture and have a very low weight. In addition, insulation with extruded polystyrene foam will be quite cheap.
Foam insulation of an attic with a simple roof is possible, but you will have to tinker with a broken one. No matter how exactly you cut the slabs of material, it will not fit 100% tightly to the roof structures, and we have gables adjoining it. And the foaming of cracks, which is usually used in such cases, cannot be used here.
How to insulate the attic floor: foam and polystyrene
An interesting way to insulate the attic with foam plastic: a video of filling polystyrene granules under the film.
Sawdust and ecowool
Sawdust is the cheapest and most environmentally friendly material of all. As a heater, the use of the material began a very long time ago, this is, so to speak, an old-fashioned way. Sawdust has good thermal insulation qualities, they will also protect against noise. However, the material is prone to fungal and putrefactive lesions, easily absorbs water, and over time, the sawdust becomes caked. They are not suitable for insulating the roof of the attic and its gables, but the material can be used for the floor.
Warming the attic from the inside with your own hands: sawdust
Ecowool - in terms of environmental friendliness, perhaps, it is not inferior to sawdust. But in terms of technical qualities - much better. Ecowool does not cake, does not rot and is not affected by fungi. The quality of heat and sound insulation is at a height, suitable for mounting on all surfaces. But it’s impossible to do the insulation of the attic with ecowool on your own - the technology requires special equipment.
Insulation of the attic gable: dry blowing of ecowool under the vapor barrier membrane
Ecowool for attic insulation. Video of wet application of the material.
Insulation of the attic floor with polyurethane foam
About the insulation of the attic with polyurethane foam, the reviews, for the most part, are very good. It is universal in application, it is equally suitable for warming gables and ceilings, as well as for a mansard roof. The material does not settle, does not absorb water, during its installation there will be no gaps or joints, which means that there will be no heat loss associated with them. Attic insulation with PPU is done very quickly, however, as in the case of ecowool, polyurethane foam is applied to the surface using a special apparatus.
Which insulation to choose for the attic: polyurethane will be an excellent option, but you will have to call specialists to perform the work.
How to properly insulate the attic: video of the PPU spraying process.
https://youtube.com/watch?v=DUFV8okh_xw
Ecowool
Relatively recently, a new insulation has appeared on the construction market - ecowool. For its production, newspaper waste is used, which is pre-crushed and treated with flame retardants and antiseptics. At the same time, dangerous lead, which, according to many, is contained in newspapers, is completely excluded from ecowool.
The composition of the material fully complies with environmental requirements, even in the process of smoldering and with a sharp change in temperature. This property makes ecowool more efficient and profitable compared to mineral wool and expanded polystyrene.
But due to the lack of popularity, insulation with this material is performed only by specialized construction organizations.
How is heat transfer in the attic
Work on the insulation of the attic began to be carried out after the installation of the heating system in the attic, because such materials allow you to keep warm air in the middle of the house. In the absence of a heating system, the installation of thermal insulation does not always give the desired effect. The heat here is retained by a small air gap, which is located between the ceiling and the roof, this is also facilitated by a layer of snow on the roof.
When installing the heating system on the attic floors, the heated air will tend to rise, it will quickly heat the roof and melt the snow. To reduce energy losses, the owner of the house must provide for the insulation of the facade of the building. This work can be done in one of the ways described below:
1. Insulation of the roof of the house from the inside. In this case, it would be advisable to lay insulation mats in the space between the roof rafters. This method of reducing energy losses is considered one of the most costly, but in some cases it is considered the only possible solution. Many people ask what is the best way to insulate the roof of the attic. One of the possible options is the installation of mineral wool with further laying of a vapor barrier film.
2. Another method of insulation is external thermal insulation. Experienced builders recommend this particular method, because when joining insulation plates, the possibility of forming cold bridges decreases. It is desirable to carry out such work during the installation of the roof, while the heat-insulating materials are laid on a vapor barrier film. This element is fixed with stapler brackets to the rafters. At the final stage of work, the insulation is protected from moisture with a waterproofing film, the roll products are fixed with the same stapler and the installation of the roofing begins.
If we compare internal and external insulation, then the latter option has the worst protection against atmospheric precipitation. Materials for external insulation should keep their shape well and not let moisture through. For those who do not know the best way to insulate a mansard roof from the outside, it is advisable to choose foam.
Fibrous roll and plate heaters
This category includes:
- glass wool;
- mineral wool;
- stone (basalt) wool.
Their key advantage and at the same time a disadvantage is the ability to pass steam. Theoretically, moist warm air from the attic will escape through the breathable inner lining, heat insulator and roofing system, which will help maintain a favorable microclimate in the room. In practice, there are the following difficulties:
- an increase in the moisture content of the fibrous insulation leads to a sharp decrease in its thermal insulation properties;
- the insulation that has accumulated moisture (especially glass wool) is crushed, deformed, forming cold bridges;
- the wood of the truss system begins to rot from contact with moisture.
To avoid these problems, it is necessary to mount a vapor barrier on top of the insulation from inside the room. A waterproofing material must be laid between the roofing and thermal insulation..
Super diffusion membrane
Styrofoam
Belongs to the group of rigid foams. According to the production technology, there are two types - press (PS) and non-press (PSB).
Thermal conductivity in dry form is almost the same as that of mineral wool. But in real operating conditions - a little lower. Therefore, it is usually noted that expanded polystyrene has better heat-insulating properties.
One of the most inexpensive thermal insulation materials. Easy to install.
Low water absorption - from tenths of a percent to 2 - 4%. But it is able to accumulate moisture, which, when frozen, destroys fragile bonds between the individual "capsules" of the material.
The main disadvantage in the operating conditions of the mansard roof is low vapor permeability. When insulating in several layers, part of the wooden structural elements may be between the insulation and the vapor barrier (for example, a crate or a counter-crate). This can lead to wetting of the wood and the appearance of rot, and it can already “infect” the supporting structure.
The second disadvantage is flammability. Although they produce “self-extinguishing” PSB-S polystyrene foam with flame retardant additives (refers to low-combustible materials), it also releases toxic gases upon contact with fire.
Foam plastics are not noise-absorbing materials. Under certain conditions (as part of structures with thin sheet sheathing), they can even amplify noise at certain frequencies.
polyurethane foam
Spraying with polyurethane foam is a good way to insulate the attic. In addition, the material has the following properties:
- Excellent degree of thermal protection.
- The possibility of insulation without a frame and special fasteners.
- The absence of seams, which are always conductors of cold.
- Creation of tightness in hard-to-reach places.
- No reaction with any roofing material, excellent resistance to moisture and vapor permeability.
- Good grip on any surface.
- Polyurethane foam is not afraid of rodents and insects, and is also not affected by mold and rot.
But PPU still has a drawback: it cannot be applied independently without special equipment.
