Leaks and damp walls are the most common complaints in new homes. Learn where waterproofing is needed, which systems work, and when it must be done.
Water is the slow enemy of every building. Waterproofing done right during construction costs far less than fixing leaks later.
Where waterproofing is essential
- Terrace and roof slab
- Bathrooms, toilets and utility areas
- Balconies and sunshades
- Underground sump and overhead water tanks
- Basement and retaining walls
- External walls facing heavy rain
Common systems
- Cementitious coatings — for bathrooms, tanks and sumps.
- Liquid-applied membranes (polyurethane, acrylic) — flexible, good for terraces.
- APP/SBS bituminous membranes — heavy-duty protection for roofs and basements.
- Integral waterproofing compound mixed into concrete and plaster.
- Brick-bat coba with slope — the traditional terrace method, still effective when done well.
Getting it right
- Do it at the right stage: bathrooms before tiling, terrace before the final screed.
- Give terraces a proper slope towards outlets and rounded corners (fillets) at wall junctions.
- Seal pipe penetrations carefully — most leaks start there.
- Do a water ponding test for 24–48 hours before covering.
