Customers often inquire about the reasons behind loose or hollow tiles. There are multiple contributing factors, many of which stem from on-site construction issues that may not be immediately apparent to clients. Examples include: inadequate cleaning of the wall substrate; insufficient wetting of the wall surface, which reduces the bonding strength of the mortar; dust or debris left on the back of the tiles, weakening adhesion; and improper application of mortar, which can also lead to tile instability.
Beyond construction-related causes, certain product quality issues may also play a role, such as:
1. Substandard Tile Water Absorption Rate
If the water absorption rate is too high, the ceramic body tends to be porous and overly absorbent. This makes the tile prone to expansion and contraction with temperature changes, potentially resulting in surface cracks or even complete detachment. Conversely, if the water absorption rate is too low—particularly for wall tiles—the tile cannot adequately absorb moisture from the cement mortar, preventing a strong bond from forming and significantly increasing the risk of tile failure.
2. Incorrect Cement Grade Selection
The grade of cement mortar indirectly influences its curing performance and bonding effectiveness with tiles. If the grade is too low, adhesion will be poor. If the grade is excessively high, rapid hydration heat release and accelerated water evaporation—especially under significant ambient temperature fluctuations—may cause cracks to develop. Weak bonding in such cases can lead to tiles loosening or detaching.
3. Improper Cement Mortar Mix Ratio
Conventional tile installation often relies on site-mixed cement and sand as the bonding agent. The moisture within the cement paste is absorbed by the tiles, facilitating curing and creating a mechanical grip on the wall. The success of this method depends heavily on the correct ratio of cement to sand. An imbalanced mix—excessive sand content, omission of redispersible polymer powder (RDP), or insufficient additive quantity—can prevent the mortar from properly adhering to the tiles. Moreover, if too much water is added to the mix, the mortar may gradually separate from the tiles during the drying process. This is precisely why #Mixeon engineers exercise meticulous care when adjusting water content in formulations—often starting with an initial addition of 200 grams, followed by incremental adjustments of 20 grams, and sometimes even fine-tuning with as little as 5 grams.
4. Poor Quality or Improperly Graded Sand
Low-quality sand can compromise the structural strength of cement mortar, eventually contributing to hollow spots or tile detachment. Sand selection also involves considerations of particle size distribution (grading). Ideally, sand with moderately uniform particle size should be used as the sole aggregate. If a blend of sands with varying coarseness is employed, the proportion must be carefully controlled. Proper grading—mixing sands of different fineness to fill voids between particles—enhances the density and overall integrity of the mortar.
