Brick Selection for Decoration·Issue 3
In December 2021, the Ministry of Housing and Urban-Rural Development issued an announcement on the "Category of Elimination of Construction Processes, Equipment and Materials Endangering Production Safety in Housing Construction and Municipal Infrastructure Projects (First Batch)". The announcement stated that in order to prevent and resolve major accident risks in housing construction and municipal infrastructure projects, reduce construction safety risks, promote the elimination of backward technology, equipment and materials in the housing and urban and rural construction industries, and improve the safety production level of housing construction and municipal infrastructure projects, the Ministry of Housing and Urban-Rural Development The first batch of elimination catalogs was organized and formulated in accordance with relevant laws and regulations. Among them, the "cement mortar pasting process for facing bricks" is listed as an elimination process.
The announcement requires relevant practitioners to completely stop using the construction techniques, equipment and materials prohibited in the elimination catalog 9 months from the date of the announcement; After 6 months, newly started projects shall not use restricted construction techniques, equipment and materials listed in this Catalog within the restricted conditions and scope. It is worth noting thatthe eliminated “veneer brick cement mortar pasting process” refers to the use of on-site cement mortar to paste exterior wall facing bricks. This also means that after September 2022, all new housing construction and foundation projects will be completely prohibited from using cement mortar to paste exterior wall bricks.
Why is the cement mortar pasting process banned? What are the safety risks associated with the cement mortar pasting process? After the ban, what other processes can be used as alternatives? ...To address these issues, Zhongtaojun will share relevant knowledge today.
Cement mortar paste has low cost but many disadvantages
The cement mortar pasting process is currently the most widely used ceramic tile paving process in China. Cement mortar refers to the adhesive for ceramic tiles and is relatively cheap. The bonding principle of this process The mortar is embedded into the pores of the ceramic tiles to form mechanical bite, thereby bonding the ceramic tiles. Although this traditional ceramic tile laying process is low in cost and widely used, it has many shortcomings. Mainly the following three aspects:
First, the bonding force of cement mortar is limited. Nowadays, the specifications of ceramic tiles are getting larger and larger, and the water absorption rate is lower after the ceramic tile technology is upgraded. This change puts forward higher requirements for the bonding strength of the ceramic tile paving process. The bonding force of cement mortar is limited. When the ceramic tiles are larger and the density is higher, using this process to paste ceramic tiles, especially wall tiles, will easily cause tiles to fall off and slip, which will affect the decoration effect.
Second, cement mortar requires on-site mixing, which is not environmentally friendly and requires high technical requirements. Due to environmental protection considerations, national construction standards do not allow on-site mixing of cement, sand, concrete, etc. At present, large-scale projects have begun to be implemented, and small projects and home decoration are not yet mandatory. However, on-site mixing is prone to produce sand, dust, garbage, etc. It is not conducive to future environmental protection development needs. In addition, the cement mortar pasting process has high technical requirements. Whether the proportion of cement mortar is reasonable, whether the mixing is uniform, the cement label and shelf life will directly affect the bonding force. The technical level of the construction personnel also has a great impact on the paving effect.
Third, there is a common hollowing phenomenon in cement mortar. When cement mortar is used to paste ceramic tiles, it is easy to cause hollowing, because the cement will hydrate when it comes into contact with water (the hydration of cement will continue to occur within 20 years), causing the cement mortar to continuously shrink and solidify. , in the long run, the ceramic tiles will become hollow and cracked. In addition, sand has poor water retention and is easily robbed of moisture by the base surface, causing the tiles to become hollow and weakly adhered.
It can be seen that there are great hidden dangers in using cement mortar to paste ceramic tiles, especially wall tiles, which can easily cause hollowing and falling off. In recent years, incidents of falling and injuring people from exterior wall bricks have occurred frequently, which has had a great impact on social stability. Prohibiting the use of cement mortar to paste exterior wall bricks can further prevent potential accidents and reduce construction safety risks.
Although the cement mortar pasting process is prohibited from being used in the construction of exterior wall tiles, this process can still be used in the paving of interior wall tiles and floor tiles in ordinary home improvement projects.
Tile adhesive may be fully popular
With the advancement of paving technology, cement mortar is no longer the only choice for pasting ceramic tiles. The emergence of new adhesives such as premixed materials and tile adhesives has made it easier to pave ceramic tiles with tape. Come for more choices. In the ceramic tile laying process, ceramic tile adhesive has gradually been popularized in recent years and is often used in home decoration projects. It has the potential to replace cement mortar.
Tile adhesive is a kind of adhesive for pasting ceramic tiles, tiles, floor tiles and other decorative materials. It is composed of cement, quartz sand and a variety of additives. It iscompared to traditional cement mortar It has better adhesiveness and anti-falling ability, and also has excellent impermeability, anti-aging properties and good water resistance, temperature resistance and freeze-thaw resistance. Different from cement mortar, the bonding principle of ceramic tile adhesive is to produce a substance with adhesive force through the composite reaction of inorganic materials and organic materials to tightly bond the substrate and ceramic tiles.
Compared with cement mortar that requires on-site proportioning and mixing, tile adhesive is scientifically proportioned by the manufacturer. The product formula is consistent and the bonding force is more stable. It is very suitable for the currently popular low water absorption rate. and large format tiles. At the same time, the process of pasting tiles using tile adhesive is simpler, and steps such as wet walls and soaked tiles can be omitted.
Generally speaking, tile adhesive uses a thin paste method to adhere tiles. When paving, first mix water according to the proportion to form a paste, then use a toothed scraper to scrape a layer on the wall and the back of the tiles to ensure uniform stripes on the surface, and finally press the tiles onto the wall. The thickness of the thin-laying method is about 3-5mm, but the bonding strength is 3-4 times that of traditional cement mortar.
What other tile laying techniques are there?
If you want to lay the ceramic tiles well, the ceramic tile laying technology and auxiliary materials are crucial. In addition to the cement mortar and tile adhesive mentioned earlier, people have also developed auxiliary materials and tools to enhance bonding strength and paving techniques with better bonding effects, such asTile backing adhesive, wall roughening, and wet hanging. , dry hanging, etc.
Tile adhesiveAlthough the name is similar to tile adhesive, its functions are completely different. Tile adhesive is a tile adhesive, and tile back glue is an auxiliary material that improves the bonding strength between tiles and adhesives. The method of use is to use a brush to apply an even layer on the back of the tiles. After the adhesive is completely dry, use an adhesive (cement mortar or tile adhesive) to lay the tiles.
Wall roughening has a similar function to ceramic tile adhesive. It is a method that improves adhesion by increasing the friction between the wall and the adhesive. The construction technology with knotty effect. The specific operation is to mix the interface agent into the cement mortar, then apply it on the waterproof layer of the wall, and finally use a scraper to scrape out burrs on the mortar layer to make the roughened layer bumpy. The interface agent can make the cement mortar layer better bond to the waterproof layer.
Wet hanging is to bond copper wire on the back of the tile, then nail steel nails on the wall, and finally wrap the copper wire around the steel nails to increase the Adhesion, and use cement mortar as a bonding material to bond the tiles and the wall together. Dry hanging of ceramic tiles is also a new technology for laying ceramic tiles. It is a construction method that drills holes above and below the wall tiles and uses a certain amount of steel as a support to fix the wall tiles. Compared with the use of adhesives, the dry-hanging process is convenient to construct, safe and environmentally friendly, and the performance of the tiles itself can also be better protected, making it less prone to deformation, hollowing, etc.
