Recommendation points
- The essence and structure of a glass-magnesium sheet
- Why LSU are considered defective
- Correct industry of application
- Recommended technology for constructing the frame and stripping sheets
- Chemistry and mixtures for leveling, LSU finishing
Today we will consider one of the most controversial materials for “dry” finishing. Glass-magnesium sheets (MSL) were positioned as a full-fledged replacement for drywall, but they did not meet the expectations. Is this material really so hopeless or does it just require a special mounting technology?
The essence and structure of a glass-magnesium sheet
A glass-magnesium sheet, it is also a glass-magnesite plate or LSU – sheet finishing material made from mineral raw materials. Expanded perlite or vermiculite is used as a base filler..
A mixture of magnesium oxide and magnesium chloride, better known as Sorel cement, is used to bind the filler particles. The quality of bonding with such a composition is very high, it is used as the main binder in the production of abrasive and emery wheels..
In order to preserve the shape of the LSU during the molding, drying and transportation process, it is reinforced on both sides with fiberglass mesh and / or fiberglass. The result is a material with absolutely inert components, no residues of solvents and other unsafe chemicals.
The physical and mechanical properties of a glass-magnesium sheet are in many respects similar to drywall. Density up to 1200 kg / m3, high strength, good adhesion, the ability to bend with a radius of three meters. Among other things, LSU are characterized by a very high fire resistance and low thermal conductivity, which allows the material to be used both as a heat insulating layer and to increase fire safety in buildings on a frame made of metal structures..
A separate topic for conversation is the moisture resistance of glass magnesite. Almost all manufacturers claim that their products are absolutely not susceptible to moisture saturation and wetting, do not lose strength and do not change their linear dimensions. It was this that became a stumbling block and caused so much controversy about the viability of such material as LSU..
Why LSU are considered defective
The main reason for the controversy about magnesite glass is simply an incredible amount of negative reviews on the network. Someone had a warped ceiling sheathed with LSU, someone became an eyewitness of a tile torn on the body after six months of operation. It would seem that it is possible to finally put an end to the glass-magnesium sheets, if not for one thing: this material continues to be successfully used in very large-scale construction projects of national importance with very high acceptance requirements.
The main problem is the lack of any marking on the products, which makes it difficult to determine both the type of sheets and their compliance with the certified products. Unscrupulous manufacturers actively use this, making building materials from raw materials of dubious quality and in every possible way violating the production technology.
Another snag is the incorrect definition of the scope. LSUs were initially positioned as a full-fledged replacement for drywall, although this is far from the case. More precisely, only one type of LSU is suitable for free replacement of gypsum plasterboard and gypsum fiber boards. Among all the others, it is the only one with markings and belongs to the class of materials “Premium-Etalon”. But such a replacement is extremely unprofitable for economic reasons, therefore, the use of stelomagnesite of any class in the construction should be justified by the project.
Correct industry of application
The vast majority of products on the domestic market are of very mediocre quality, the moisture resistance of such sheets is very conditional. Such LSUs can be used exclusively for technological purposes, they are not suitable for finishing.
From cheap sheets with a density of up to 950 kg / m3 it is possible to arrange a fixed formwork, separating layers of fire protection and insulation. Also, cheap glass magnesite can be used as a damping substrate for a screed and as a roofing layer that protects polymer insulation from high temperatures.
It is possible to distinguish sheets of different classes not only by density, but also by the price of the material – the quality also rises in proportion to it. On the other hand, if the distributor agrees to transfer sealed copies of the certificates of conformity and fire safety, as well as the hygienic conclusion for a specific batch of products, such sheets can be treated with a greater degree of trust and used for interior wall decoration in residential premises..
Ceilings can be trimmed and used in facade works only with Premium + and Premium-Standard LSUs with the appropriate certification documentation. Their moisture resistance is close to absolute, their service life is from 30 years.
Let us recall that replacing the “dry” cladding with LSU is advisable only if it is necessary to ensure the minimum sensitivity to moisture or high fire resistance. In other cases, high-quality glass magnesite is an unjustified waste of money.
In fairness, it is worth mentioning a number of examples of the successful use of LSU in fairly harsh conditions. In particular, there is a known case of using such sheets as a temporary roofing: first under heavy autumn rains, and then under a significant snow load at frost down to -40 ° C, the sheets did not lose their characteristics and could subsequently be used for interior decoration. But this exception only confirms the rule: the quality of cheap Chinese products differs from batch to batch, and the methods of visual detection of defects have not yet been determined..
Recommended technology for constructing the frame and stripping sheets
Having correctly established the scope of a particular type of product, it is necessary to adhere to the correct sequence and installation technology. LSU is positioned as a lightweight material; therefore, instead of 12-16 mm thickness of plaster-filled plating, one layer of LSU with a thickness of 8 mm is often offered. This is a fundamentally wrong conclusion: strength is strength, and the deflection of sheets with a standard spacing of rack profiles of 60 cm will be more than noticeable.
It is recommended to install the racks more often – up to 40 cm, or to make the cladding multi-layer. In special cases, LSU of low quality and gypsum plasterboard can be combined, this will have a good effect on the sound and thermal insulation of premises. In addition, LSU will serve as a hygroscopic “pillow” and will harmlessly take on excess moisture from damp stone walls, preventing the drywall from getting wet above the norm.
Another subtlety in the installation of LSU is the hiding of the fastener heads. With a density over 800 kg / m3 the hardness of the sheet does not allow it to be pushed through with a conical head. This is not so important with multi-layer cladding, but on the front surfaces you have to use either self-centering screws or reaming with a drill, which negates the speed advantage of working with light material.
When finishing the facade, LSU is recommended to be protected from moisture oversaturation. On the inside, it is enough to restrict the passage of steam with a membrane, on the outside, a thin protective layer of wet plaster should be provided.
Chemistry and mixtures for leveling, LSU finishing
The rest of the subtleties in working with glass-magnesium sheets relate to their processing after installation. Sealing of joints and attachment points is done with a rubber or acrylic putty. Serpyanka and paper are useless in strengthening the joints, it is necessary to use carbon fiber or glass tape, the use of adhesive polyurethane mastics is allowed.
Leveling and filler LSU are also made with acrylic or latex fillers. Using gypsum compounds, you cause a heterogeneity in the perception of fluctuations in humidity and temperature, due to which the liner from LSU will be more susceptible to warpage.
The main difference in the finishing of glass magnesite is the almost complete absence of base preparation. The cladding does not need priming, it already has excellent adhesion. To paint the walls on a layer of putty, a minimum leveling and cosmetic layer of the latter is required over the entire plane. Wallpapering can be carried out without continuous puttying after sealing the seams and fasteners, but one or two impregnation with wallpaper glue is still recommended to eliminate the increased hygroscopicity of the surface.
Can anyone share their experience with using magnesium glass sheets for decoration purposes? I’m curious about its advantages and disadvantages compared to other materials. How does it hold up in terms of durability and aesthetics? Any specific brands or types of magnesium glass sheets that you recommend or caution against? Your insights would greatly help in making an informed decision.
I have used magnesium glass sheets for decoration in the past, and I must say that they offer a sleek and modern look that can add a unique touch to any space. One advantage of magnesium glass sheets is their durability – they are resistant to scratches, cracks, and dents, making them a long-lasting option for decoration. Additionally, they are easy to clean and maintain, which is a plus for busy households.
However, one disadvantage of magnesium glass sheets is that they can be more expensive compared to other materials like regular glass or acrylic. Additionally, they are heavier and may require professional installation due to their weight. In terms of aesthetics, magnesium glass sheets have a high-end feel and can give a luxurious look to any room.
As for specific brands or types, I recommend looking for reputable manufacturers that offer high-quality magnesium glass sheets to ensure that you are getting a product that will last. It’s also essential to consider the thickness and size of the sheets based on your specific needs. Overall, magnesium glass sheets can be a great choice for decoration purposes, but it’s crucial to weigh the advantages and disadvantages before making a decision.