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Today we will consider a popular and effective heat-insulating material, known for more than half a century, which is called glass wool. What is it?
Composition
This fibrous insulation is one of the varieties of mineral wool. It is made by drawing fibers from silicon with additives from limestone, soda, dolomite, borax, etc., with the addition of a synthetic binder. It differs from other varieties of mineral wool in that glass wool has a greater thickness of fibers and better elasticity.
Specifications of glass wool
The thermal conductivity of glass wool is 0.039-0.05 W/m*K. The heat insulator in glass wool is the air itself, which fills the cavities formed between the interlacing of fibers. It can be operated at temperatures up to 450 degrees.
Insulation properties:
- low thermal conductivity;
- good soundproofing characteristics;
- incombustibility;
- elasticity and compressibility;
- ease and simplicity of installation;
- durability.
Application of glass wool
Modern glass wool is a non-combustible insulation that is used for thermal insulation of roofs, internal and external walls and partitions, floors and ceilings of residential and technical premises. Under the condition of good moisture protection, glass wool can be used to insulate facades. Reviews about this heater for many decades have been consistently good. It is ideal for warming the garage and basement. In the photo and video you can see numerous applications. When installing the plates, it is compressed and forms a monolithic heat-insulating coating without cold bridges.
Advantages
One of the main advantages of glass wool over basalt mineral wool is its cost. It is an order of magnitude cheaper due to the more affordable cost of raw materials and due to cheaper transportation. Glass wool has excellent compressibility and elasticity and is able to reduce its volume in the package by 6 times. When unpacked for 20-40 minutes, it restores its volume. The most well-known manufacturers of glass wool are Isover, Ursa, Rockwool, etc. Glass wool is produced in slabs, rolls and mats, it can be produced reinforced and with a reflective layer.
disadvantages
The disadvantages include excessive water absorption. During installation, mandatory vapor barrier is required. When saturated with moisture, the insulation deteriorates its thermal insulation properties by up to 40%. In addition, when saturated with water, the fibers irreversibly change their structure to a more fragile one.
Glass wool is a fibrous insulation material belonging to the mineral wool class. It is considered one of the most popular heat insulators.
In the article we will consider the properties, manufacture and use of glass wool.
Glass wool production technology and its characteristics
Fiberglass is made from glass industry waste and natural sand. As a result, the material is the thinnest fibers interconnected by a substance.
Thermal insulation products based on glass wool are mats or rolls:
Due to the pressing of the material several times, it occupies a small volume. In expanded form - more or less rigid plates.
Features of working with glass wool
It should be remembered that during any work with glass wool, it turns into fine dust, which causes irritation of the skin, mucous membranes or enters the lungs, from where it is never excreted. Therefore, it is necessary to take care of personal protective equipment - gloves, goggles, a respirator.
To increase the strength, fiberglass materials are reinforced by stitching:
Another disadvantage (apart from brittleness) is the thermal conductivity, which is greater than, for example, that of polyurethane foam or penoizol. That is, glass wool, as a heater, is worse than the named materials. But it's cheaper.
Benefits of glass wool
- High sound insulation (as the sellers say, but I didn’t notice this in my frame extension, although there are four layers of glass wool - 20 cm);
- low density and light weight;
- high strength (again, at the request of sellers, who probably just have tongues without bones and heads without brains - what kind of strength does glass wool have if it exfoliates in their hands?);
- ease of installation;
- elasticity and flexibility;
- low cost;
- occupies a small volume in packed form;
- ease of transportation;
- not subject to mold and attack by rodents;
- modern cotton wool is relatively safe (the main word here is "relatively").
I would like to add a comment.
The expression, which concerns the safety of the use of glass wool, is completely unreliable.
Once again, safety precautions should be reminded:
In case of contact with the skin, you should try to rinse with water without scratching the skin; otherwise the fibers will go deep under the skin.
If the fibers get on the mucous membrane - immediately see a doctor! (in a sense, this is what doctors advise, but in reality, depending on what kind of mucous membranes: you yourself wash your eyes with plenty of running water, you don’t need a doctor for this; and fiberglass dust is not removed from the respiratory tract by any doctor, so why? For a wallet. ..).
one). The use of tight work clothes is mandatory.
2). During installation, the wool layer should be covered with other material to prevent dust from penetrating into the room where people are.
3). If the insulation is indoors, then after the work of the room it is good to vacuum.
The main disadvantages of glass wool
Actually, we have said exhaustively about them above, we will not crush the water.
My review of glass wool Knauf (Knauf)
I would like to leave a review in this article on such material as Knauf brand fiberglass.
Packed in rolls:
Or mats:
I used cotton wool produced by mats. It is called "Thermoplate 037", represents light series glass wool.
Characteristics:
Mat dimensions 5 x 60 x 125 cm,
Thermal conductivity coefficient 0.037.
There are 24 mats in the package, the total area of the mats in the package is 18 m2 (at the same time, you need to buy with a margin if you want to insulate in two or three layers. With what margin? It is believed that 5 ... 10% is spent on trimming any material, these are numbers and figure it out).
Material manufacturer: KNAUF Insulation LLC, Stupino, Moscow region.
Insulation was for the walls of the frame extension to the house. I placed glass wool between the uprights and ceiling joists:
My review of Material in Action:
- It is great to cut sheets, cut with both a sharp knife and scissors (large, tailor's, not manicure :)).
- I confirm that rodents definitely will not settle in glass wool (the packaging was in a room accessible to gray animals, but the settlement in the insulation itself did not occur).
- The density of this type of Knauf is low, so the material is not fully adapted for thermal insulation of vertical structures. On the packaging, the density, unfortunately, is not indicated. It is better to inquire about the density of glass wool in advance on the Internet or other sources, so as not to get a "pig in a poke" (this is not the cat that will disperse the mice :)).
- Despite the manufacturer's assurances that cotton wool is formaldehyde-free and does not have a pungent odor, in reality there is a smell. Therefore, it is better to work with a respirator, and, again, make the inner walls airtight.
I note that the use of rolled Knauf is much more convenient for horizontal ceilings. Firstly, the convenience of rolling over the surface. Secondly, with multi-layer insulation, the layers will be without joints, and, therefore, without getting cold into the room insulated with such material.
The overall assessment of the material is quite good, and in the absence of a better alternative, I would use it in the future. But there is an alternative, something I'll tell you someday ...
Application of glass wool
Due to its efficiency and versatility, this thermal insulation material has a wide range of applications in construction. Glass wool is more suitable for warming attic, interfloor, that is, horizontal ceilings. Of course, it is also possible to insulate vertical structures (see photo above; the fact is that cotton wool does not creep along unplaned boards, you just need to make the distance between the boards less by 1.5 ... 2 cm of the width of the insulation).
Which insulation is better: glass wool or mineral wool?
If I had to choose between glass wool and mineral wool, then I would still choose our building material - glass wool. One of the most important advantages that especially attracted me is that mice and other living creatures did not start in it.
Yet. With the same thickness, glass wool is 10 ... 15% warmer than basalt wool and cheaper. Glass wool has longer fibers than stone wool, so less glue is used in the manufacture of glass wool, which means less formaldehyde.
Mineral wool should be used only where it is possible to put a reliable layer from the penetration of formaldehyde into the living space. In general, it should be used wisely for facade insulation, because health (its absence) is an even more expensive thing than building a house.
I made my choice, I hope that my review will be useful to you, and you will also make your right choice.
glass wool specifications
Thermal insulation materials are used in construction very often. Each of them has individual technical characteristics, among which the dimensions of these products are not the last. It is known that only 5 cm of insulation will successfully replace 20 cm of a concrete base. Having studied the insulation, the dimensions of which correspond to the design features of the building, you can build a warm and comfortable home, build a roof, foundation and walls.
There is a fairly large number of thermal insulation samples. Basalt insulation is the most popular, the size of its plates corresponds to standard standards, it practically does not deform during installation. Extruded polystyrene foam is an incredibly shrink-resistant raw material that can withstand high pressure without absorbing dust and moisture. Having a thickness of 2-3 mm, it surpasses other samples in terms of quality. Warming with mineral wool is achieved due to air pores located in the space between the fibers.
Insulation with a solid base most often has a slab configuration. Their thickness can be different: the minimum value corresponds to 20 mm. The standard dimensions of the plates are equal to 1250x600. Some models have some differences in dimensions: 1000x600x50, 1000x500x30. Flexible versions of such sources are produced in rolls of different lengths, respectively, the insignificant height of the product indicates its greater volume in such a bundle. Therefore, the dimensions can have such coefficients: 9000x1220x50, 3900x1200x150.
Varieties of mineral heaters
- Fiberglass.
Such an insulator has a small mass, has a soft coating and is absolutely safe for humans. It is made by melting glass, has elongated, massive fibers. Such insulation is produced in the form of rolls and plates. Even under the influence of unfavorable external factors, glass fibers do not change their properties, dimensions and configurations.
Plates from this raw material are produced by gluing with synthetic resins. Rigid and semi-rigid bases differ in the following dimensions: 1000X1500X50-70 mm. Fiberglass strips and mats look like packages treated on both sides with glass wool and stitched with cotton threads. Such bases are most often used for pipeline insulation. The dimensions of the mats correspond to the following parameters: length - 1400, width - 500; 900; 1000 and 1500, thickness - 30; 40; fifty; 60; 70 and 80 mm.
- Basalt heaters.
Such insulators are produced by melting basalt and similar minerals. Their external features are similar to fiberglass raw materials. The structure of basalt threads makes it possible to reduce mechanical loads. The use of such samples in practice contributes to high-quality insulation of facades, walls, floors, pitched roofs. The basalt insulator does not allow moisture to penetrate into the room, does not let in extraneous sounds. Therefore, there is no dampness and mold in the premises.
Taking into account the average performance of the heat-insulating material, their dimensions correspond to: 1200x600x100; 1000x600x100; 1200x600x50; 1000x600x50 mm. The difference between such indicators is determined by the variability of the requirements of each of the manufacturers, whose standards may differ slightly.
- Mineral wool.
Mineral wool insulators are produced in the following versions: some are in the form of plates, others are produced in the form of rolls.
Both tiles perform the same function, determined by the conditions of the installation work. Insulation in the form of rolls is convenient for rooms with large areas.
To ensure convenience during the installation of thermal insulators, dimensions are set for each brand of product. The dimensions of mineral wool boards are 1000-1200 mm long and 500-600 mm wide.
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Polymer based materials
Heat insulators of this type are actively used in damp rooms. The disadvantage of insulation from the category of polymers is a low degree of fire resistance.
- Expanded polystyrene foam.
Such insulators incorporate granules, the size of which corresponds to 2-8 mm, and a flame retardant foaming agent. The weight of the insulation boards of this variety is practically absent: lightweight blocks are freely cut to the desired dimensions. In the process of heating, the granules increase in volume. A 5 cm high layer of this material laid on the surface will provide high-quality room insulation, hydro and sound insulation. Ready-made polystyrene blocks have a length of 800 cm to 6000 cm. The average width is 1200 mm.
- Extruded polystyrene foam.
Such material is produced in the form of plates, their traditional sizes are: 1250x600. They are very easy to cut, easy to fit. Another name for this insulator is penoplex. In order to achieve high coefficients of thermal insulation and absorption of extraneous noise in your home, it is recommended to use a thicker material. You can find out these values from the markings presented on each of the packages: 15, 25 and 100.
A remarkable advantage of such plates is the self-installation of these samples. For indoor installation, sheets with a thickness of 15 mm are often used. A higher insulator contributes to a reduction in room area. For this reason, its values are determined by the dimensions of the insulated object.
The length and width indicators for such plates are standard: 60 cm and a length of 120-240 cm.
- Expanded polyethylene foam.
This is a heat-insulating material from the category of polymers, produced by foaming with chemical and physical blowing agents. When installing it, there is no need to use a vapor barrier layer. It is produced in the form of rolls, the width of which is equal to 0.5-1.5 meters, the thickness is from 2 to 15 mm.
- Polyurethane foam.
It has the appearance of infusible plastic with a mesh base. It is used as a heater for windows, doors, roofs and external walls.
Are you going to insulate your home and decided to use glass wool? I will talk about the features and characteristics of this material, how fiberglass insulation differs from similar types of thermal insulation. And you will no longer have questions about what glass wool is.
Features of glass wool
What it is
Glass wool is a fibrous heat insulator, one of the varieties of mineral wool. It is used in the construction of buildings for the insulation of walls, roofs, foundations and ceilings, as well as for the laying of pipelines for the thermal insulation of pipes.
Glass wool and mineral wool are not two different heaters. The first is a variation of the second. Nevertheless, many people call it slag (or stone) mineral wool, and glass is considered a separate species. This is mistake.
Once again: there are several varieties of mineral wool according to GOST 31913-2011 (EN ISO 9229:2007), which can be compared with each other:
- Fiberglass wool.
- Basalt or stone wool.
- Slag cotton.
Comparison of slag wool with mineral wool does not make any sense. Fiberglass also consists of mineral compounds, respectively, materials based on it are mineral products. Therefore, glass wool can be defined as a kind of mineral wool.
Technical specifications
To determine the quality and operational features of the material, it is necessary to refer to the numbers. Specifications of glass wool:
As you can see, glass wool insulation shows good performance: low, high vapor permeability, elasticity, shape memory, excellent soundproofing qualities. This played a decisive role in the choice of glass wool as one of the most common heat insulators.
Advantages and disadvantages
The main advantages of glass wool:
- Low thermal conductivity. This indicates the effectiveness of the material as thermal insulation;
- low density. Glass wool applied to the wall or roof elements will not create a serious load on the supporting structures;
- Good compressibility. Cotton wool can be compressed 6 times without affecting the quality. After unpacking, the material quickly restores its original volume. This property plays an important role in the transportation and storage of the material;
- Fire safety. The substance does not burn and does not support combustion. Thermal insulation can perform its functions at a temperature of about 450 ° C and protect various structures from fire;
- Chemical inertness. Cotton wool does not react to most chemicals used in everyday life, including gasoline, acetone, organic solvents, solutions of acids and alkalis;
- No corrosion. Fiberglass is not afraid of mold, bacteria, electrochemical reactions, insects, etc. Glass wool and rodents do not get along well;
- Low price. This is one of the cheapest thermal insulation materials;
- DIY styling. Installation work does not require special skills and knowledge.
Thanks to a set of these advantages, glass wool remains the No. 1 heat-insulating material for insulating heating mains, various industrial pipelines, chimneys, etc.
Disadvantages of glass wool:
- Harm to health. The material has a number of harmful effects on humans, ranging from skin itching and allergies, ending with eye damage and serious lung diseases;
- Hygroscopicity. Like any cotton wool, our heat insulator is able to absorb a large amount of moisture. Because of this, its resistance to heat transfer drops, so it makes no sense to mount it without additional vapor barrier;
- Shrinkage. The fragility of the fibers leads to the fact that over time, cotton wool shrinks. As a result, gaps or open areas may form in the insulation layer;
- Short service life. In comparison with other heat insulators, glass wool is inferior in terms of service life;
- The need for overalls. For laying the fiberglass insulator, protective clothing and a respirator are required.
Glass wool or basalt wool?
As you know, the truth is known in comparison. Let's take the closest competitor of glass wool - stone (basalt) wool.
We check the stone wool slab for strength, for this we take it in two places and shake it:
We see the result almost immediately:
If you continue the test, the result will be even more deplorable:
After that, I took the plate by the other end, and it completely broke in half:
Now let's check this material for shape memory: is it capable of restoring its original volume after compression? To do this, I stepped on the stove:
Let's look at the result:
Now we shake the glass wool:
After shaking, nothing came off, the sheet remained intact. Now let's try to fold, or rather crumple this sheet several times:
We look at what happened to the stove after we crumpled it:
In the previous experience, we had branded fiberglass wool and basalt insulation from a little-known cheap manufacturer. Let's change the conditions.
We shake a sheet of cheap fiberglass:
As you can see, the result resembles the previous experience, but exactly the opposite. Now let's shake the URSA stone wool slab:
Crumple a sheet of basalt insulation:
The sheet remained intact, I can even poke my finger into it hard enough - the material does not pierce and does not deteriorate from my blows:
Let's check the basalt for shape memory:
Let's see what happened as a result of compression:
Obviously, the quality of materials is highly dependent on manufacturers. But then a reasonable question arises: what is the difference between glass wool and stone wool, if we take products from the same manufacturer? Stone wool is not so harmful, it does not shrink and has a long service life.
fire resistance
To complete the picture, let's check if the glass wool burns. A piece of stone wool will again act as a control sample, since this type of mineral wool is considered the best. So, we put two pieces of insulation:
We take a gas burner and start burning both pieces:
Then we try to set fire to the fiberglass wool:
As a result, we see the following picture:
Let us subject the materials to a more severe test. Let's direct the fire of the blowtorch at one point and try to burn through the stove through.
I will say right away that both samples gradually succumbed and holes formed in them, which indicates that mineral wool heaters are destroyed when heated above a predetermined limit.
I clearly showed that, despite the fire resistance of mineral fiber insulation, it is impossible to exceed the temperature that the instruction defines as the maximum allowable. Otherwise, the material is destroyed.
Output
I talked in detail about the properties and characteristics of glass wool. Conducted experiments that demonstrated which is better - glass wool or stone wool. More information in the video in this article, watch and leave comments.
Today it is impossible to imagine thermal insulation without mineral wool. Indispensable in construction and repair, it is suitable for all types of surfaces. One of the oldest types of material is glass wool. Despite the emergence of new forms, this one is still in steady demand.
It is made from melted glass. At a temperature of +1450°C, a fiber is drawn from a mixture of sand and broken glass (secondary raw material). The semi-finished product is glued into small bundles using a synthetic or bituminous binder, heated to +200°C to polymerize thermosetting resins, and pressed into glass felt of a certain thickness. It is then cut into mats or rolled into rolls.
According to the properties of glass wool, it differs significantly from basalt and slag material. Due to their length (on average 5 cm) and softness, glass mats are more elastic, lighter and have better elasticity, which allows to reduce the volume by 5 times. This feature becomes noticeable during storage and transportation, since the compressed material takes up much less space. And after unpacking, glass wool rather quickly takes its original shape, which allows it to be used in structures of any configuration, and without additional spacers and fasteners.
Thanks to additives, manufacturers began to produce insulation based on glass wool fibers in the form of rigid plates and shells intended for pipelines of water supply, heating, air conditioning and ventilation systems. Laminating with aluminum foil provides protection against moisture and UV rays. The only limitation is that the temperature on the surface of the pipes should not exceed +250°C, otherwise the polymer resin will begin to break down.
In addition, glass wool provides sound insulation (noise and shock), has vibration damping and windproof qualities.
Specifications of glass wool
| Parameters | Indicator for glass wool | Indicator for basalt wool |
| Length, m | 1,25-3,9 | 1,20-2 |
| Width, m | 0,6-1,2 | 0,5-1 |
| Thickness, mm | 50-120 | 40-200 |
| Density, kg / cu. m. | 11-25 | 28-100 |
| Fiber length, cm | 5-7 | 1,5-3 |
| Fiber thickness, microns | 16-20 | 8-12 |
| Thermal conductivity, λ10, W/(m*K) | 0,029-0,041 | 0,032-0,048 |
| Thermal conductivity λА, W/(m*K) | 0,036-0,042 | 0,039-0,059 |
| Thermal conductivity λB, W/(m*K) | 0,039-0,047 | 0,041-0,089 |
| Vapor permeability, mg / mch * Pa | 0-0,6 | 0-0,9 |
| The degree of flammability of glass wool | NG, G1 | NG |
| Water absorption coefficient for partial and short-term immersion, kg/m2, | 0,6-0,8 | 0,6-1 |
| Compression ratio in a package, times | 2-5 | 0,5 |
| Operating temperature | From -60 to +250°C | From -40 to +750°C |
As can be seen from the table, glass wool retains heat better than basalt material. This fact is explained by the fact that longer and thicker fibers are twisted into a kind of "cocoons" filled with air, which limits thermal conductivity.
Glass wool as a heater is used for:
- outdoor works (Knauf Aquastatik Facade, Isover Ventfasade);
- horizontal surfaces (Knauf Thermo Roll, Tisma P-15);
- roofing works (URSA Geo, Isover Pitched roof);
- partitions and internal walls (Knauf Insulation, Isover Classic Plus);
- sound insulation (series of glass wool Acoustic URSA, Knauf).
For each of the listed areas of application, its own types of felt have been developed. They differ in density, thermal conductivity, the presence of additional coatings (aluminum foil, foamed polyethylene, waterproofing film) and the arrangement of fibers (to give better soundproofing properties). Accordingly, depending on the destination, the price also varies. The cheapest and thinnest fiberglass mats and rolls are used for interior work, the most expensive and effective for facade work.
Care should be taken when handling it - glass wool is harmful to health. The fibers are quite fragile, crumble easily, and, getting into open areas of the body, can cause minor scratches, itching and irritation. Therefore, the manufacturers themselves strongly recommend the use of all kinds of protective equipment (tarpaulin suits, rubber-coated gloves, and others).
Glass wool dust is especially harmful for people suffering from lung diseases (asthma, tuberculosis, allergies). Therefore, it is better to limit its use for interior finishing work. The exception is glass wool for plaster.
In addition, another disadvantage is the fear of water. Under the influence of steam, the insulation gradually collapses and crumbles, so it is advisable to cover it with a waterproofing film.
Manufacturers
The most famous are 3 brands of manufacturers: URSA, Knauf, Isover. Below is a comparative table of average prices for similar types of glass wool in Moscow and the Moscow region:
| Type of insulation | Glass wool URSA | Glass wool Knauf | Glass wool Isover |
| Universal plates, thickness 5 cm, | 800 | 1100 | 700 |
| Exterior processing of buildings (facades for plaster and brick, ventilated facades), rolls, thickness 5 cm | 1200 | 1400 | 1300 |
| Roofing, rolls, thickness 1.5 cm | 1100 | 1300 | 1000 |
| Interior decoration, partitions, floors, rolls, 5 cm | 1200 | 1400 | 1300 |
| Foil wind and steam protection, for pipelines, rolls, 5 cm | 2600 | 2100 | 1800 |
| Sound insulation, mats, 5 cm | 1200 | 1700 | 1000 |