Waterproofing & tiling
Waterproofing is one of the most common defects in Australian residential construction, and it sits underneath the tiles, so it cannot be inspected or redone without lifting them. These answers cover what the code requires and how to tell an upsell from a real failure.
16 pages in this topic
Questions
- The tiler says my bathroom needs waterproofing again. Is that real?Usually yes, if tiles are being lifted. The waterproof membrane sits underneath the tiles and screed, so it cannot be inspected or renewed without removing them, which is why the two jobs are quoted together.4 sources cited
- How long should bathroom waterproofing last?A correctly installed membrane should last the life of the bathroom, twenty years or more. Failure inside ten years usually indicates an installation defect rather than wear, and may be a building defect you have rights over.5 sources cited
- What are the signs of a shower leak?Damp or bubbling paint on the other side of a shower wall, drummy tiles, a musty smell that cleaning does not fix, and lifting floorboards nearby. All point to water escaping the wet area.4 sources cited
- Where does a bathroom exhaust fan have to vent to?It should discharge outside the building. Venting into a roof space dumps moist air into an enclosed cavity, which causes condensation, mould and, over time, damage to timber and insulation.4 sources cited
- Why does mould keep coming back in my bathroom?Mould returns because the moisture source is still there. Cleaning treats the symptom, and unless ventilation, a leak or a cold surface is addressed, it will regrow in the same place.4 sources cited
- Should I regrout or reseal my shower, or does it need rewaterproofing?Regrouting fixes deteriorated joints between tiles. It does not fix a failed membrane underneath, and if water is appearing outside the shower, the membrane is the more likely cause.4 sources cited
- How long should bathroom waterproofing last?A correctly installed membrane should last the life of the bathroom, commonly twenty years or more. Early failure is almost always an installation defect rather than the membrane wearing out.5 sources cited
- Why does water pool on my shower floor?The floor does not have enough fall to the waste, or the fall runs the wrong way. It is a screed problem under the tiles, so correcting it properly means lifting the floor.4 sources cited
- Is a hobless shower a good idea?A hobless shower is more accessible and looks better, but it removes the physical barrier that kept water in, so it depends entirely on the fall, the screen detail and the waterproofing being right.4 sources cited
- What does it mean when tiles sound hollow?A hollow or drummy sound means the tile has lost its bond to the substrate. It is not always urgent, but in a wet area it is a path for water and it tends to spread.4 sources cited
- Why does my balcony leak into the room below?Balconies are exposed to weather, movement and ultraviolet light in a way internal wet areas are not, and the usual failure points are the membrane at the door threshold, the drainage outlet and the perimeter junctions.5 sources cited
- Should the joint between wall and floor tiles be grout or silicone?Internal corners and the wall-to-floor junction should be flexible sealant, not grout. Those are movement joints, and grout in them cracks, which is the most common cause of a shower that starts leaking.3 sources cited
- Can you tile over existing tiles?It is possible on some floors and walls with proper preparation, but in a wet area it is usually the wrong call, because it buries the existing waterproofing and adds height at the door and the waste.4 sources cited
- What is efflorescence and is it a problem?Efflorescence is mineral salt left behind when water moves through masonry or a tile bed and evaporates at the surface. The deposit itself is harmless, but it tells you water is moving where it should not be.4 sources cited
- What causes rising damp and how is it fixed?Rising damp is ground moisture drawn up through masonry where the damp proof course is absent, bridged or failed. It is far less common than it is diagnosed, and most persistent low-level damp has another cause.4 sources cited