Causes and Prevention of Water Spots on Carrara Tile Mosaic
Causes of Water Spots
Water spots on Carrara tile mosaic are primarily caused by the cement mortar used in wet construction methods. This happens because:
- Cement contains 1%–2% sodium hydroxide, which strongly absorbs water.
- In humid conditions with temperatures exceeding 35°C, sodium carbonate solution forms, which is corrosive.
- The crystal water content fluctuates with temperature changes but never fully evaporates, causing persistent wet marks.
Methods of Prevention
To prevent water spots, it is essential to protect the Carrara tile mosaic and reduce exposure to moisture from cement and the environment. Key preventive measures include:
1. Waterproofing Treatment
- Apply a high-quality marble mosaic protective agent on all six sides of the tile before installation.
- Pay special attention to the bottom layer protection.
2. Modify the Installation Method
- Avoid using cement for installing marble mosaics whenever possible.
- If cement mortar is necessary:
- Monitor moisture content in the mix.
- Use semi-dry cement mortar instead of wet mortar.
- Apply the bottom squeegee method rather than pouring semi-dry mortar over the leveling layer.
3. Ensure Proper Ventilation
- Design and reserve water vapor channels during installation.
- Pay close attention to caulking the Carrara tile mosaic joints to prevent water penetration.
