Insulation For The Roof - Which Is Better: Types With Descriptions, Characteristics And Reviews

2024 Author: Bailey Albertson | [email protected]. Last modified: 2023-12-17 12:53

Choosing a roof insulation: from mineral wool to penoplex

The huge space under the roof of the house is now being turned not into a warehouse, but into a comfortable and spacious living space. But in order to keep the attic warm in winter and cool in summer, it should be insulated in compliance with the technology. We will help you choose a budgetary, durable and easy-to-use heat insulator and familiarize you with the nuances of its use.

Content

• 1 What is recommended to insulate the roof

  • 1.1 Roof insulation with foam

  • 1.2 Insulation of the roof with penoplex

    1.2.1 Video: technology of roof insulation with foam

  • 1.3 Roof insulation with polyurethane foam

    1.3.1 Video: how polyurethane foam is sprayed

  • 1.4 Roof insulation with mineral wool

    1.4.1 Video: roof insulation with mineral wool

  • 1.5 Thermal insulation of the roof with ecowool

    1.5.1 Table: comparison of characteristics of basalt and cellulose wool

  • 1.6 Roof insulation with expanded clay
  • 1.7 Foamed roll roof insulation
  • 1.8 Roof insulation with fiber boards

• 2 What insulation is better to use for a private house

  2.1 Video: testing different types of heaters

• 3 Reviews about roof insulation

What is recommended to insulate the roof

The building materials market offers many options for heat insulators, but sellers usually talk only about the advantages of the material and rarely warn about the shortcomings. Therefore, it is important to figure out which material and in which situation will be more preferable.

The effectiveness of insulation is very different: a more modern material can have tens of times less thickness with the same heat-insulating ability

The "correct" insulation must meet the following requirements:

• easy to install (since the roofs in our region are pitched rather than flat, preference is given to materials that can stay on an inclined surface);
• to be safe in installation and use (for example, glass wool is unpleasantly pricked during installation, and foam, when heated, releases carcinogens);
• do not support combustion (since the main structure of the roof is made of wood, the use of combustible insulation can lead to the rapid destruction of the house);
• be lightweight (any heat insulator is an additional load on the roof structure, walls and foundation);
• differ in small thickness (the larger the heat insulator layer, the lower the ceiling height in the attic).

Roof insulation with foam

Polyfoam is one of the most popular heat insulators, since it is one of the cheapest. The slab material is easy to transport and install, does not overload the roof structure, is completely unaffected by moisture, so rot and mold are not afraid of it.

Polyfoam is the best option for external insulation, therefore it is worth choosing it if the roof of your house is flat. It will help insulate the roof without losing internal space. If you bought the attic above your apartment in a multi-storey building, you can increase its height from 2.2-2.3 to 2.5-2.6 m only by transferring the heat insulator to the outer layer. True, for this you have to agree on similar work with other residents of the upper floor or with the management company.

This material is quite dense, it is not afraid of water, so builders use foam plastic for thermal insulation of floors. Plates of expanded polystyrene are poured into the screed when arranging the floor in the attic.

You will have to spend a lot of construction foam to process all the cracks

However, with the internal insulation of the roof between the rafters, the disadvantages of foam are found:

• the plates are not elastic, so there are gaps between them that must be blown out with polyurethane foam;
• expanded polystyrene interferes with ventilation of rafters and other wooden frame elements, which can lead to their destruction by rot or fungus;
• foam has a rather low degree of sound insulation, so if it is important for you to cut off unnecessary sounds, it is better to choose a less dense insulation;
• if the thickness of the material is incorrectly calculated, the dew point is inside the insulated space and the heat-insulating cake begins to collapse;
• modern polystyrene does not support combustion, but it melts at high temperatures and releases toxic substances, so if a stove or fireplace pipe passes through the attic, it is better to insulate the space around it with other material.

In addition, polystyrene foam is unpleasant for many in work, since when cutting and rubbing with hard surfaces, it emits repulsive sounds (a similar reaction is caused by the grinding of metal on glass).

By the way, when equipping a green roof with grass and ornamental plants, foam is used for thermal insulation, because it does not deform under the weight of subsequent layers of drainage and soil.

The green eco-friendly roof is not only beautiful, but also very warm, because there is foam under it

Roof insulation with penoplex

From a chemical point of view, Penoplex is a new generation of foam. This material is produced in the form of hard orange slabs with no visible granules. It differs from the usual expanded polystyrene:

• tongue-and-groove edge, which helps to join the slabs without gaps, so the seams do not need to be foamed and then the foam should be cut;
• higher density, due to which the roof increases resistance to snow loads;
• homogeneity, due to which the board does not crumble when cut;
• lower thermal conductivity, which allows you to reliably insulate the slope with a 2 times smaller layer of insulation and maintain the height of the ceiling in the attic.

Penoplex inherited water and steam resistance from its older brother, resistance to the influence of fungi and bacteria, the ability to serve for a long time and the absence of dust when cutting. It can also be mounted in any weather and humidity level. Installation of foam without insulating membranes is allowed.

In the roofing pie, when the roof is insulated with foam, there may be no hydro and vapor barrier film

But despite all the efforts of the manufacturer to rid the material of flammability, the polymer remains dangerous in case of fire. Of course, it will not ignite by itself and will not burn without direct contact with fire, but the smoke released during melting can poison the residents of the house.

Video: roof insulation technology with foam

Roof insulation with polyurethane foam

Polyurethane foam is also a close relative of expanded polystyrene, but unlike the latter, it is not sold ready-made. The chemical reaction that creates polymer bumps takes place on your roof, so polyurethane foam is guaranteed to fill the slightest gaps between the rafters. In addition to ensuring a uniform seamless coating, the material has other advantages:

• high heat, hydro and sound insulation without cold bridges with a moderately thick layer of material, which allows you to maintain the height of the ceiling (the total thickness is three times less than when using foam or cotton wool);
• no need for additional work (installation of fasteners, battens), enough dust removal and surface priming;
• fire safety (the material does not support combustion, does not melt at temperatures up to +220 ^o C);
• suitable for the most northern regions (normal operating temperature up to -150 ^o C);
• not afraid of fungus and rot.

Experts note that if the material is protected from ultraviolet radiation, polyurethane foam insulation can last more than 30 years.

You can insulate the roof with polyurethane foam not only inside, but also outside

What are the sellers not talking about? For example, that polyurethane foam should not be applied directly to the roofing material or the membrane adjacent to it. Since the foam adheres firmly to the base, it becomes impossible to equip the ventilation gap necessary for these materials, and the roof covering slowly deteriorates. Of course, you can hem the slope with membrane-protected boards or OSB boards at a short distance from the main covering and apply foam to this skin. But such events will inevitably lead to a rise in the cost of the project, so some craftsmen prefer not to mention the nuances when talking with homeowners.

Taking into account all the requirements of technology, polyurethane foam turns out to be a very good choice for all types of houses and roofs, because it is not without reason that it is considered the most popular heat insulator in Europe and the USA.

Video: how polyurethane foam is sprayed

Roof insulation with mineral wool

In our region, mineral wool is most often used to insulate a pitched roof. One of its main advantages is ease of installation. The technology is so simple that even one adult with a teenage assistant can insulate a stingray with its help. But mineral wool is different:

• glass (glass wool). It is perfect for insulating heated elements (for example, stove and fireplace pipes), as it can withstand heating up to 450 ^° C. In addition, wool insulates extraneous noise, quickly restores its shape after shock and vibration. One of the main disadvantages of glass wool is flowability. While working with it, the master runs the risk of breathing in a huge amount of the smallest fragments of glass fibers, and when cotton gets on the skin, the hands and feet begin to itch and redden (this is not an allergy, but microscratches). As a result, the installation has to be carried out in overalls and a respirator, which makes the process long and uncomfortable;

  

  Glass wool releases the smallest particles of fibers interspersed with glass, which unpleasantly scratch the exposed areas of the skin

• stone (basalt wool). Stone wool is more resistant to moisture, does not crumble so quickly and keeps its shape longer. Therefore, you can not be afraid that the heat insulator will slide down the slope over time. In addition, basalt wool can be mounted without personal protective equipment, it is safe for health and practically does not cause itching.

  

  Basalt wool is easy to distinguish by the brown-brown color of long strands

Both types of cotton wool are produced in the form of mats of several standard sizes and in rolls. If the roof is simple and it is possible to adjust the pitch of the crate (and the size of the cell) to the parameters of the mat, it is best to use soft slabs that will themselves hold in the cells. For roofs with complex slopes, ledges and bay windows, it is better to buy rolled cotton wool, although it will require additional fastening.

Mineral wool is an effective but capricious material to use. In particular, it should be protected from moisture from above and steam from below, and natural ventilation should be provided. Such requirements will result in additional costs for hydro and vapor barriers, and the work will take longer due to the construction of another crate.

Those who ignore the rules, after the first autumn, can admire the wet rotting insulation and the unpleasant cold in the attic. And if the situation is not corrected, over time, the rafters will begin to rot.

Video: roof insulation with mineral wool

If you see a soft snow-white insulation in a store, this is not know-how, but a variation of quartz sand mineral wool with acrylic binder. Studies have confirmed its safety for health, therefore, it is recommended to insulate the attic with such cotton wool if it is planned to make a children's room in it. In addition, white glass wool holds better when installed, it does not smell and does not tend to dust, so the installation process is much easier than installing ordinary brown glass wool.

Quartz wool is most often produced in rolls and is the safest type of mineral wool for health.

Thermal insulation of the roof with ecowool

An even safer and more natural analogue of mineral wool is cellulose ecowool. This material is available in slabs or as loose fibers that slightly resemble fluff. Among the advantages of ecowool:

• natural composition;
• combustion resistance (class G2);
• good resistance to decay, insects, rodents and fungi (treated with safe impregnants - brown or boric acid);
• preservation of properties when wet;
• high degree of thermal insulation (4 times higher than that of expanded clay);
• environmental friendliness. Does not cause allergies during installation;
• the formation of a seamless layer of thermal insulation;
• frost resistance.

Ecowool is produced in different modifications, and the higher its class, the more it looks like a medical one.

Table: comparison of the characteristics of basalt and cellulose wool

Material characteristics	Stone wool	Ecowool
Origin of raw materials	Basalt and dolomite combined with artificial binders, contains phenol	Cellulose from wood and recycled paper with added natural minerals
Thermal conductivity, W / m 2	0.037 - 0.044 (increases with wetting)	0.038 - 0.041 (almost independent of humidity)
Density, kg / m 3	35 - 190	42-75
The degree of adhesion to structures	Voids remain, seams are visible	The voids are filled, the seams are missing
Water vapor permeability, mg / m * h * Pa	0.3	0.67

Of the disadvantages of ecowool, only the need for equipment for ventilation of the material and the complexity of installation can be distinguished. It is better to spray cotton wool in the form of fluffy fibers using a blowing machine, but if you have time and are not inclined to save on the amount of material, this can be done manually. This is the only cotton wool that can be wetted for ease of installation.

Among the natural analogues of mineral wool, one can also note heat-insulated (slabs of linen fibers), but in appearance, characteristics and installation features, it does not differ much from mineral wool.

Roof insulation with expanded clay

Expanded clay (foamed clay granules) attracts attention with such properties:

• environmental friendliness (it consists entirely of mineral components without the addition of polymer resins and other popular binders);
• resistance to mouse teeth (it just does not attract the interest of rodents, who gladly arrange nests in mineral wool and foam);
• long service life (50-60 years for expanded clay is not the limit);
• extremely low thermal conductivity (a layer of 10 cm of expanded clay insulates heat like 25 cm of timber or 100 cm of brick).

At the same time, the cost of the material is not exorbitant, it is considered one of the most budgetary heaters.

It looks like a roof insulated with expanded clay in a section

The disadvantage of expanded clay can be considered the fact that it is used only during the construction of the roof or its complete reconstruction. Since the material is free-flowing, closed cells of the required depth should be prepared for it. For this:

1. The slopes are hemmed from the inside (with OSB, fiberboard, clapboard).
2. A membrane is laid on top.
3. A layer of expanded clay (14–16 cm) is poured onto it and leveled.
4. Laying waterproofing.
5. Sheathing, counter battens and roofing material are mounted.

It is almost impossible to qualitatively insulate the finished roof with expanded clay.

Foamed roll roof insulation

Among the rolls of insulation for the roof, fully polymer ones are also offered, which look like a substrate for a laminate. In most cases, these are:

• penofol (foamed polyethylene) with a layer thickness of 3-10 mm, which can be supplied with one- and two-sided foil and an adhesive layer;
• penotherm (expanded polypropylene) 6–10 mm thick, with or without foil.

Products similar in properties and composition are also produced by the brands Izolon, Alyufom, Polifom, Jermaflex, Ekofol and others.

The foam insulation is so thin that the rolls for the entire roof can be brought in a car

These materials are extremely thin, but in combination with foil, they can provide reliable thermal insulation of the attic. Due to their low weight and low thickness, they are great for owners of old houses who are not ready to reinforce the roof and foundation structure. Foamed polymers are completely safe during installation, and due to the coating of pure aluminum, they are not able to emit any harmful substances into the atmosphere of the attic. The material simultaneously serves as heat, moisture and noise insulation; no films or membranes need to be mounted with it. Penofol is also used when the ceiling height is critically low. To maintain the height of the attic, it is not even necessary to cover it with finishing, the foil ceiling will look unusual and futuristic.

At the same time, penofol and penotherm can be used in combination with any other types of insulation, from mineral wool to fiberboard. Such a multi-layer cake will improve your thermal insulation several times, and the foam insulation is no more expensive than a good waterproofing membrane.

When using penofol instead of a membrane, the effectiveness of mineral wool increases significantly

The only drawback of the foam heat insulator - low temperature resistance, they begin to deteriorate when heated to 91 ^about C.

Roof insulation with wood fiber boards

Previously, ceilings and floors were insulated with a mixture of sawdust with the addition of cement. Fibrolite is a more modern variation of this technology, but it has also been known for a long time. In the USSR, there were more than 40 factories producing this material. Unlike chipboard, with which it is sometimes confused, fiberboard does not consist of shavings, but of longer wood fibers (which resemble straw). In addition to them, the slabs contain Portland cement and liquid glass, so this material is less flammable, heavier and is not afraid of moisture, like chipboard.

Fiberboard plates can simultaneously serve as a heater and a base for finishing (painting or putty)

Now fibrolite is not considered a heater, it is more often used for sheathing the frame of a house, building partitions and solid roof sheathing. But at the same time, fiberboard plates have a low coefficient of thermal conductivity, therefore they are used for insulation both by themselves (more often in two layers with displacement of the sheets), and in combination with softer insulation materials (mineral wool, ecowool). Moreover, it is suitable for all types of roofs (flat, single, gable, complex). Unlike other types of heat insulators, fiberboard can be putty, paint and wallpaper, which greatly simplifies the finishing of the room.

A distinctive feature of these wood fiber boards is excellent thermal stability. For example, mineral wool under a metal tile will heat up in 2 hours in a summer afternoon, and fiberboard will not change the temperature for 10 hours. The material is so thermally stable that it is possible to equip weldable roofs (roofing felt, bitumen shingles) on it using open flame burners.

The disadvantage of fiberboard can be considered a higher price than that of other heat insulators, but if we take into account that the plates simultaneously perform bearing functions, their cost is fully justified.

Which insulation is best for a private house

In private houses, roofs are usually pitched, therefore, when insulating, it is better to focus on soft materials, leaving foam and foam for external insulation of flat roofs. The final choice depends on the roof configuration and finishing material. For example:

• for a roof of complex shape, polyurethane foam and ecowool are well suited, which can provide a seamless coating;

• a roof with a continuous crate, through which water is guaranteed not to leak, can be insulated with any kind of cotton wool;

  

  In private housing construction, the most widespread are wadded heaters

• if the roof will be completely rebuilt, it is worth insulating with expanded clay during construction;
• for a wooden house with high fire safety requirements, non-combustible materials are suitable - ecowool, expanded clay, fiberboard;
• in houses with a low attic, it is required to save space, so it is worth using foil-clad penofol or penotherm;
• when the roof is high with an acute angle, the cotton wool can slide down, so it is better to insulate with polyurethane foam, foamed roll heat insulator or fiberboard.

When buying insulation, be sure to ask a consultant whether the variety you have chosen is suitable for the roof, since cotton wool, foam, foam and other materials for roofs, walls and ceilings differ in density, size, thickness of plates and other characteristics. Take the time to read the information on the packaging - most manufacturers indicate the purpose of the material.

Video: testing different types of heaters

Reviews about roof insulation

Now you know about popular products and builders recommendations. It's time to get the opinion of homeowners who have already taken advantage of the proposed technologies.

Keep in mind that reviews are not always objective, and the effectiveness of insulation depends not only on the chosen insulation, but also on the correct ventilation of the attic and under-roof space. Therefore, if you saw an unflattering opinion about the selected material, first discuss the technology in detail with a professional and only after that make a decision whether or not to refuse it.

Having familiarized yourself with the variety and properties of insulating materials, you will undoubtedly be able to choose the best option for your home. The main thing to remember is that the implementation of any project begins with a thorough study of the information.