Why do tiles change color?

The house that just moved in suddenly changed color, and the chief culprit was tile, floor and wallpaper. It turns out that these three pieces are naturally "chameleons", but experts have listed the matters needing attention in the process of purchase, paving and use. If you are prepared in advance, it will effectively reduce discoloration. Case: Zhu Xiao still remembers that after staying for one month, the wall tiles in his bathroom began to change color. The original opalescent glazed tiles are incongruous gray, and the deeper they look down, the deeper the color becomes. He found a shop selling wall tiles, and the factory sent people to watch it for half an hour. Before he left, he told Zhu Xiao, "This is not the quality problem of the tile itself, but the problem in the process of pasting, so we need to find a decoration company." So, Zhu Xiao found the company that decorated him at that time, and the company also sent a mason to see it. The mason didn't study it very much, and told Zhu Xiao directly: "The moisture content of these bricks is too high, and they will change color when they absorb water." This time, Zhu Xiao was completely confused. Which party should bear the responsibility for discoloration? In the market, we found Mr. Wang who has been engaged in ceramic tile sales for many years. In his view, the probability of color change or color difference of wall tiles is not high. Generally speaking, as long as the tiles are genuine, there will be no discoloration or chromatic aberration, while the antique tiles are relatively prone to chromatic aberration due to the firing and glazing process. However, he also recognized the mason's statement: "The discoloration of tiles is indeed related to water absorption." So when you buy wall and floor tiles, you must pay attention to their water absorption and glaze crack resistance. Bricks with good quality have low water absorption and good glaze crack resistance, while bricks with thin and uneven glaze will change color as long as the surface is stained with water. Teacher Wang demonstrated a simple and effective test method on the spot. He picked up a brick, dropped a drop of water on the back of the brick, and then observed the speed at which the water penetrated into the brick. He said that if seepage velocity is slow, it means that the water absorption rate is low. In addition, Mr. Wang said that it is best to go to an agent shop or a direct store to buy bricks. These stores usually only make bricks of one brand, and the purchase channels are formal, and the quality is relatively guaranteed: "Be careful when you meet stores that sell several brands of bricks at the same time, and you may encounter bricks with unknown sources, or sell big-name defective bricks and defective bricks as genuine products." Farewell to Mr. Wang, let's go to Maifeng Decoration to verify another question: Will sticking bricks lead to brick discoloration? Master Cheng, who works in a decoration company, also gave a positive answer: "It has an impact." According to the situation of Zhu Xiao's family, he suggested that Zhu Xiao take a closer look at whether the floor tiles have changed color. If so, it means that waterproofing was not done well at the beginning, and now it may be that there is leakage on the wall and ground. Many years of construction experience made Master Cheng feel: "The toilet should be waterproof at least twice, and the experiment time of rising water should be no less than 48 hours." But in another case, only the wall tiles change color, and the floor tiles have no effect at all. Master Cheng thinks that it may be that the bricklayer is lazy and sticks the bricks that have not been soaked in water or not soaked enough to the wall, which causes the bricks to absorb the water in the cement and then change color. Finally, when buying, the owner had better remember to ask whether this brick is suitable for acidic or alkaline cleaning agent. If the wrong cleaner is used, it will destroy the glaze and eventually lead to discoloration.