Drips, white staining and drummy tiles usually point to the same few causes. How to read the signs and what a proper repair involves.
Water always finds the weakest point. On balconies, podiums and planter boxes, the damage often shows up a floor below, or years after the leak started.
Signs to look for
- White crystalline staining (efflorescence) on soffits, walls or grout lines.
- Drips or damp patches on the ceiling below after rain.
- Tiles that sound hollow when tapped, lift or crack.
- Rust stains or spalling concrete near edges and drainage outlets.
- Mould or a musty smell in rooms beside the area.
Common causes
- Membrane not turned up high enough at walls, doors and hobs.
- Poorly detailed drains with no proper connection to the membrane.
- Not enough fall, so water sits instead of draining.
- Cracks in the substrate that have torn through the membrane.
- Failed sealant at junctions, balustrade fixings and penetrations.
Fixing it properly
Surface treatments and new grout can buy time, but if the membrane underneath has failed, the lasting fix is to remove the finishes, repair the substrate and install a new membrane system detailed at every edge, drain and penetration. External membranes should follow AS 4654.2.
Start with an inspection. Photos of the problem area and the space below are enough for us to give you an idea of the likely scope before we visit.