Water dripping from your ceiling — especially below a bathroom — is a problem that needs urgent attention. The longer you wait, the worse the damage gets. Here’s what’s likely causing it and what you should do.

What to Do Right Now

If you notice water coming through the ceiling:

1. Stop using the shower until the cause is found
2. Place a bucket under the drip to catch water
3. Turn off the water supply to the bathroom if the leak is significant
4. Check for electrical hazards — if water is near light fittings, turn off the power to that circuit at the switchboard
5. Don’t poke holes in the ceiling — this can make things worse and spread the damage
6. Call a plumber — ceiling leaks from bathrooms rarely fix themselves

Common Causes

1. Failed Shower Waterproofing

The most common cause. Every shower recess has a waterproof membrane beneath the tiles. Over time, this membrane can fail due to:

• Age and deterioration
• Ground movement cracking tiles and grout
• Poor original installation
• Water finding its way through cracked grout or silicone

When the membrane fails, water passes through the floor and into the ceiling below.

How to tell: The leak happens during or shortly after showering, and stops when the shower isn’t used.

2. Leaking Shower Mixer or Taps

The connections behind the wall where the shower mixer or taps are mounted can develop leaks. These are hidden inside the wall cavity and can drip for a long time before becoming visible.

How to tell: The leak may be constant (even when the shower isn’t in use) if the fault is on the supply side.

3. Leaking Drain

The shower drain connection can fail where it meets the floor waste or the pipe below. Grout or silicone around the drain grate can also deteriorate.

How to tell: Water appears directly below the shower drain location.

4. Cracked or Loose Tiles

Cracked tiles or deteriorated grout let water penetrate behind the tile surface. Over time, water finds its way through to the substrate and ceiling below.

5. Leaking Pipe in the Wall or Floor

A pipe inside the wall cavity or floor slab can develop a leak independent of the shower itself. This could be a supply pipe, waste pipe, or even a pipe serving a different fixture.

How to tell: The leak may be constant and not related to shower use.

How Serious Is It?

Very. A shower leaking through the ceiling can cause:

• Structural damage — Waterlogged timber framing can rot and weaken
• Mould growth — Hidden moisture behind walls and ceilings breeds dangerous mould
• Ceiling collapse — Saturated plasterboard can sag and eventually fall
• Electrical hazards — Water near wiring and light fittings is dangerous
• Damage to rooms below — Furniture, flooring, and belongings can be ruined

The damage you can see is usually just a fraction of the total damage.

How a Plumber Diagnoses the Problem

Finding the exact source of a shower leak can be tricky because water travels along surfaces before dripping through. A plumber will:

1. Inspect the shower — Check tiles, grout, silicone, drain, and fixtures for visible faults
2. Perform a flood test — Block the drain and fill the shower base with water to test the membrane
3. Test the plumbing — Check supply pipes and connections for leaks
4. Use moisture detection — Moisture meters and thermal imaging can locate hidden water
5. Access the ceiling below — If needed, to inspect from underneath

Repair Options

Depending on the cause:

• Regrout and reseal — If grout and silicone are the only issue, this may be sufficient
• Shower base repair — Specialist waterproofing products can repair minor membrane failures without removing tiles
• Full shower renovation — For serious membrane failure, tiles may need to come off so the membrane can be replaced
• Pipe repair — Fixing leaking supply or waste pipes
• Drain repair — Reseating or replacing the shower drain connection

Don’t Wait

Every day a shower leak continues, the damage spreads. What starts as a small water stain can become a major repair job involving ceiling replacement, mould remediation, and structural work.

If you notice any signs of a shower leak — water stains, bubbling paint, damp patches, or drips — call Hankook Plumbing on 0407 756 172 for a professional diagnosis.