Bathroom Waterproofing in Randburg

Waterproofing is invisible once your bathroom is finished. You can't see it under the tiles. You can't check it's working. And that's exactly why it needs to be done right the first time — because by the time you know it's failed, the damage is already done.

Water finds every gap. A hairline crack in grout, a poorly sealed corner, an uncovered screw penetration in the substrate — any of these can let moisture through. In Randburg's older homes, where bathrooms sit above living areas or on concrete slabs, that moisture travels through the structure, causing damp patches, mould growth, timber rot, and structural weakening that costs far more to repair than the waterproofing would have cost to install properly.

Professional bathroom waterproofing involves several critical steps:

• Surface preparation — the substrate (concrete screed, cement board, or existing slab) must be clean, smooth, and free of cracks before any membrane is applied
• Crack and joint treatment — all cracks, pipe penetrations, wall-floor junctions, and corners are reinforced with fabric tape bedded in membrane
• Membrane application — a liquid-applied or sheet membrane is applied in multiple coats, building up a continuous waterproof barrier across the entire wet area
• Upstand heights — the membrane extends up walls to a minimum of 150mm above the finished floor level (1800mm in shower areas), ensuring splash water cannot bypass it
• Flood testing — the completed membrane is flood-tested for 24 hours before tiling begins, confirming there are zero leaks
• Tiling over membrane — only after the flood test passes do tiles go down, with proper adhesive suitable for bonding to the membrane surface

Every step matters. Skip the flood test and you're gambling. Skip the corner reinforcement and you're guaranteeing a future leak point.

No waterproofing at all: We strip bathrooms in older Fairland and Linden homes and find nothing between the tiles and the slab. The original builders simply tiled over bare concrete. For decades, grout was the only barrier — and grout is not waterproof. These bathrooms have been slowly leaking for years.

Insufficient coverage: Some contractors apply membrane to the shower floor but skip the walls, corners, or areas around the toilet. Water doesn't just fall straight down — it splashes, runs along walls, and finds the lowest unprotected point.

Poor corner and penetration treatment: The most common failure point is where the floor meets the wall. Without reinforced tape and extra membrane at these junctions, movement cracks form and water passes straight through. Pipe penetrations — shower mixers, waste outlets, supply lines — are another weak point that needs proper sealing.

Tiling before testing: Applying tiles before flood-testing the membrane means any failure is hidden until it causes damage elsewhere. We always test before tiling — no exceptions.

If you notice any of these, your waterproofing may have failed or may never have been installed:

• Damp patches on the ceiling below the bathroom — the clearest sign of a shower or floor leak
• Musty smell in or around the bathroom — trapped moisture breeds mould behind tiles and under floors
• Tiles lifting or hollow-sounding — moisture underneath breaks the adhesive bond
• Grout cracking or discolouring — water passing through grout lines darkens and weakens them
• Peeling paint on adjacent walls — moisture migrating through the wall structure pushes paint off
• Swollen or warped skirting boards — water at the base of bathroom walls seeps into adjacent rooms

If you see these signs, a plumber should assess the waterproofing situation before the damage spreads further. The earlier it's caught, the less expensive the repair.

If you're renovating your bathroom, waterproofing is not optional — it's the single most important structural step in the entire project. It protects the concrete slab, the walls, adjacent rooms, and the floor below from water damage for the next 20 to 30 years.

We integrate waterproofing into every bathroom renovation we do. After strip-out and plumbing rough-in, the membrane goes down before anything else. We test it, confirm it holds, and only then do the tilers begin. This sequence is non-negotiable.

Any contractor who suggests skipping waterproofing to save money is saving you nothing — they're setting up a future problem that will cost many times more than the membrane itself.

Not every waterproofing failure requires ripping out the entire bathroom. In some cases, the leak is isolated — a single failed corner joint, a poorly sealed shower screen fixing, or degraded grout in the shower floor.

We start with diagnosis: where is the water coming from, and how is it travelling? Sometimes we can access the failure point by removing a targeted section of tiles, repairing the membrane, and retiling just that area. Other times, the damage is too widespread and a full strip-out is the only reliable fix.

We'll be honest about which approach your situation needs. A patch repair on a bathroom with fundamentally failed waterproofing is a waste of your money — we'll tell you that upfront.

We provide bathroom waterproofing across Randburg and surrounding suburbs:

• Fairland — 1960s-70s homes where original bathrooms often have no waterproofing at all
• Northcliff — multi-level homes where upstairs bathroom leaks damage ceilings below
• Linden — older homes with bathrooms that have been retiled over existing (failed) waterproofing
• Parkhurst — heritage cottages where careful, non-invasive waterproofing techniques matter
• Blairgowrie — 1970s-80s homes where builder-grade waterproofing is reaching end of life
• Greenside, Bordeaux & Ferndale — mixed housing stock with varying waterproofing quality

Based in Randburg, we handle waterproofing as a standalone service or as part of a full bathroom renovation.