When choosing a thermal insulation material for a house, flat or cottage, consumers face many ambiguous comments and recommendations. It can be difficult for non-experts to distinguish fiction from the truth, especially as the authors and storytellers of myths are sometimes very eloquent and convincing. To dispel the fog of doubt and dot the i's of the choice of thermal insulation, we have compiled some frequently encountered claims and decided to explain why they are wrong.
Modern home insulation
This myth is based on the misconception that a less dense material (and rolls are made of lightweight wool) is inferior to a denser one in terms of thermal insulation properties. This is a fundamental mistake, which contradicts the laws of physics. The fact is that the primary and best insulator is air. The more it can hold the material, the more effective it is as an insulator. Lightweight mineral wool, sold in rolls, has a low density, so more air is placed between the fibers.
Figures confirm the effectiveness of this material. For example, the density of light ISOVER quartz wool grades (14-20 kg/m3) is half as high as similar in thermal characteristics stone wool boards (30-60 kg/m3). This effect is due to the structure of quartz wool: the length of its fibers is 25-30 cm with a microscopic thickness of only 3.5-5 microns, which means that the material is airy.
The second feature is also due to the structure of the fibers: with such a ratio of thickness and length, they are highly elastic and form a flexible, springy structure. Due to this, quartz insulation, cut with a small (about 5 mm on each side) margin, slightly compressed and laid in the spaces between the crate elements, flattens out and fills the entire room, leaving no thermal bridges. Unlike rigid boards, roll-fed insulation boards do not form joints and forgive installation errors - they can be moved from one construction to another without breaking or deforming.
To prove that the insulation does not slip and requires special fixing, Saint-Gobain sent samples of ISOVER quartz wool to the Tver Institute of Car Building for testing. The material was subjected to a series of vibration tests at up to three thousand vibrations per minute on a test stand that simulated conditions similar to those experienced in operation over 50 years. The test results showed that the quartz wool does not slip over the years, even from vertical surfaces, and crumble. Therefore, as a result of the tests, it has been approved as an insulation material, including company trains. For the same reason, quartz wool rolls are also a reliable solution for all types of insulation and soundproofing in individual buildings, especially on pitched roofs.
Once upon a time, back in the USSR, cheap, low-quality insulation, glass wool, was widespread. It was made of short and thick (up to 500 µm), which looked like needles. Over time, they crumbled, which is the first source of myths about short-lived mineral wool. Nowadays, this material is not produced and used.
A second reason for the misconceptions stems from the properties of rock wool used in industrial construction, which loses its original structure when it gets wet and needs to be replaced.
On the other hand, quartz wool can repel moisture, so even in an emergency, the homeowner will not have to spend money on new insulation. Tests have shown that it has a service life of at least 50 years. This means that one piece of insulation will last for the entire lifetime of a detached house.
The myth that rolled mineral wool needs additional fasteners again brings to mind the elastic properties of quartz wool due to the length and elasticity of its fibers. Specialists call it Formostability technology: the insulation material takes the shape of the cell in which it is placed and retains it throughout its entire service life, without the need for any fasteners. The main thing is to remember to leave an allowance of 5 mm on each side when calculating the width and to cut the wool so that the material can be compressed during installation.
It is not uncommon to hear from theorists that insulating roofs and walls with rolled mineral wool are uncomfortable. There is a factual error in this statement. Practice shows that the installation of roll-fed insulation on the walls is two to three times faster than pre-cut or slab insulation. The explanation is simple. If you have to install two or three boards, fixing and adjusting each one, it is enough just to cut the roll vertically, set it at the top and roll it down.
In addition, when installing the boards, the quality of the joints must be checked carefully to avoid thermal bridges (see above). In some cases, the joints are additionally insulated, and often the insulation is installed in two layers, overlapping. Using rolls avoids such complications. Besides, the lightweight, roll-fed quartz wool insulation fills the entire space between the sheathing elements, fitting snugly into the sheathing without any additional steps or fasteners.
Similar measurements of labor costs for insulating floors and pitched roofs showed that the installation is three to four times faster in the case of quartz thermal insulation material. In this case, one roll is often the length of three to four boards.
Another fact should be considered: the more significant the insulation thickness, the more time you can save on installation work. For example, for most regions of Russia, the standard thickness of insulation underlay is 200 mm. As the plates are often 50 mm thick, they have to be laid in four layers, which is time-consuming. Rolled insulation is much simpler: its thickness is 100 and 150 mm, so you only need to install one or two layers. The same applies to insulating facades. Quartz wool also retains heat more efficiently.
Buying the cheapest pack on the shop shelf will not save you money. The fact is that different manufacturers supply different amounts of m2 of material in the same size package. This is because one type of mineral wool can shrink several times, while another cannot. Not knowing this, many people either compare the price per bundle of insulation or count the volume of packed compressed rolls and compare it to the cubic size of the boards. Then how is it correct to compare prices per square meter of unfolded material? For example, roll insulation ISOVER Warm Home 100 mm thick based on quartz wool will cost less than 60 rubles per square meter. The plate's thickness and thermal insulating properties are based on 160 rubles per square meter of basalt wool. The difference is quite substantial. In addition, you will not have to overpay for scraps when insulating with rolls: they are much less than the boards.
You also have to take into account the benefits of transporting the material. Rolled quartz wool insulation is easier to load and transport on its own. Considering that it is strongly compressed in the package, it can even be placed in a private car, saving delivery. For the same reason, much less space is needed to store the rolls on a plot, in a flat or a utility room. In addition, they are much easier and quicker to carry and unload. The number of trips to and from the truck, or climbing up and down the floor, is considerably reduced.
Modern quartz-based mineral wool is a versatile, durable, and reliable insulation material with several advantages that are particularly important for private house owners and residents of blocks of flats. By using the right products for your specific needs, you can insulate your house for years to come with your resources and save significantly on the material itself, delivery, and heating bills.
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