Grout fills tile joints but is not the entire waterproofing system. Open joints can make it easier for water to reach the substrate.
Signs renewal may be needed
- Cracking or crumbling grout
- Open corners
- Darkening again soon after cleaning
- Movement or a hollow sound in tiles
- Damp marks below the area
Grout or silicone?
Moving corners and junctions usually require a suitable silicone or flexible product. Filling every junction with rigid grout can lead to renewed cracking.
Check the substrate
If tiles move or moisture reaches another area, surface renewal alone may not be enough; the substrate and waterproofing should be assessed.
