How to choose the right mineral wool for insulation

6 min

Today, mineral wool is considered one of the most popular materials used to insulate rooms. Under the term “mineral wool” there are different types of materials on the market, which are united by a similar production method. So, it can be glass wool, slag wool or stone wool, produced in the form of rolls or mats. What material is more preferable in a particular situation, we will try to figure it out.

mineral woolMineral wool is a generalized concept of all those heat-insulating materials that are obtained by blowing fibers from a red-hot mineral material. Depending on the starting material, mineral wool is divided into three different types. All of them are characterized by such properties as a high degree of thermal insulation, good sound insulation, high fire resistance and vapor permeability. The rest of the characteristics and severity of the listed advantages differ depending on the type of mineral wool. It is worth choosing the one that will best meet your requirements.

Type of mineral wool

So, it has already been mentioned that different materials can be used for the manufacture of mineral wool, depending on which the finished product receives certain properties.

slag woolSlag wool is produced from blast furnace waste, which explains such a small particle size. As a result, the resulting mats and slabs have low rigidity, but in terms of thermal conductivity they are not inferior to other types of mineral wool. It is not very convenient to work with this material, which limits the circle of its consumers, since private developers, who carry out all or almost all of the work on their own, prefer to choose those materials with which it is as easy as possible to work. Due to all this, slag wool is most often used at industrial facilities, for insulating pipes, etc., when it is possible to resort to the services of specialists and provide them with the proper level of protection, since small particles of this material can penetrate both the skin and respiratory paths, and into clothes.

glass woolGlass wool has become more widespread, but it is still difficult to work with it. This material is produced from molten glass waste or rocks, which contain a lot of silicon. Glass wool has the longest particle length, which can even reach 3 mm, which means that the material has high rigidity even with a low density, and, accordingly, low weight. But, on the other hand, these long pointed particles can easily hit a person: when working with mineral wool, they stick into the skin, respiratory tract, causing discomfort and irritation.

Mineral wool has properties such as elasticity and vibration resistance (due to its structure), so it is easy to transport: no matter how the roll is folded or the plate is twisted, the weight of the material will then straighten out and take the required form. Among other things, glass wool can boast of excellent performance in thermal insulation and sound insulation, fire resistance. It is often used in private construction, which is explained by the relatively low price, but at the same time it is worth considering the need for serious personal protection when working with such material.

stone woolStone wool is also often called rock wool, since it is made from rocks, or basalt, since most often it is basalt that is in its basis. Less often, this insulation is produced from mining waste, but in any case, a material comes out that has the best operational properties compared to its “classmates”. Stone wool is absolutely non-flammable: it can be heated up to 10 000C, and at the same time it will not melt or even start to emit any smoke. This is an absolutely natural material that keeps heat well, and due to its structure, it also acts as a good sound insulator. To all this, you can add excellent vapor permeability, no shrinkage, density and ease of installation: just cut off the necessary piece and insert it into the opening intended for this. At the same time, the structural features of the material allow you to work with it without additional protection, which means that the whole process of insulation is simplified, therefore this material still remains the most appropriate in private construction. But you have to pay for all these advantages: stone wool is much more expensive than glass wool, and in the process of working with it you will notice that it is also not very elastic.

Slabs or rolls?

Since slag wool is not used in private construction and is produced mainly to order from enterprises, then we will only talk about glass wool and stone wool. Depending on where and how the insulation will be used, one or another form of its release is chosen.

mineral wool 2Glass wool is produced in the form of slabs and rolls. Plates are usually pasted over in the production process with fiberglass, non-woven material or aluminum foil, and each of the options, due to the properties obtained, is best used in well-defined situations. For example, glass wool coated with fiberglass is used for ventilated curtain walls in order to ultimately obtain maximum wind protection. Glass wool with foil is excellent for roof insulation, insulation of floors in attics and basements. Glass wool in a roll is more suitable for insulating horizontal surfaces, and its advantage is that the number of joints can be reduced to a minimum.

Basalt wool is also available in slabs and rolls, can be reinforced with foil or fiberglass, and the scope of application is approximately the same as glass wool. The only thing to note is that stone wool can also be produced in several other forms. So, there is granulated cotton wool, which, with the help of a special installation, is blown out where other insulation cannot get, thus covering the most inaccessible places. Mineral slabs are covered with a bituminous layer, which makes them an ideal material for roof insulation, but lamellar slabs have a special structure. In them, all the fibers are located perpendicular to the surface: the heat-insulating properties from this do not increase, but elasticity increases, which means that curved surfaces can be insulated with them.

When is mineral wool used?

mineral wool 4By the combination of the described properties, it can be understood that mineral wool is an excellent insulation that is suitable in most situations. And the fact that there are no organic components in its composition means that the material will be as durable as possible. In addition, the fibrous structure allows air from the room to freely penetrate into the street, so that as a result, excess moisture does not stagnate in the house. A similar “breathing” effect will come in handy when you need to insulate a wooden or stone house.

Many users fear that rock wool can clump, losing its properties. This, indeed, can take place, but this process is very extended in time, and it is facilitated by a change in humidity, temperature, strong vibration, etc. It is worth noting that such deformations are more common with less dense mats than with rigid slabs, so you may need to look at the latter.

Some nuances of choice

mineral wool 3When planning to buy insulation, pay attention to some other nuances in order to choose a quality material that has the maximum set of positive qualities and durability. So, it is important that the mineral wool is stored correctly: it is better that it was the factory packaging, shrink wrap and a rain canopy. If the material is packed in cardboard boxes, and special types of mineral wool are often sold, then it is important that they are stored in a dry place. Buying at least a little bit of cotton wool is a waste of money, because once it dries, it becomes unusable. The name of the manufacturer also means a lot, as well as reviews about a specific brand, so before buying it is better not to be lazy and find out the opinion of those who have already encountered a specific type of product.

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Passionate about DIY for over 10 years and all the new tools, I give you through this blog all my advice, tips, tests in all areas: carpentry, electricity, masonry, gardening, home automation ...


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