Water leaking from the bottom of a shower usually comes from a failed screen or perimeter seal, a cracked or moving base, a leaking waste connection, failed waterproofing or a concealed water-supply leak. Where and when the water appears can indicate the fault, but may not confirm it because water can travel before becoming visible.
Likely causes and clues
| What you observe | Likely fault category |
|---|---|
| Water escapes near the door or screen when spray reaches it | Misaligned screen, worn door seal or failed perimeter silicone |
| Water appears beneath the waste while the shower drains | Failed waste seal, loose connection, damaged trap or drain pipe |
| Water emerges beneath a cracked or flexing base | Damaged base or failed base-to-wall junction |
| Dampness develops after corners or floor-to-wall junctions get wet | Junction defect or possible waterproofing failure |
| Moisture appears while the shower has not been used | Concealed hot- or cold-water supply leak, or another nearby source |
Cracked grout or failed silicone may indicate a problem but does not, by itself, prove that the concealed waterproofing membrane has failed. Grout is a surface finish, not the waterproofing layer. Under the Australian standard for domestic wet area waterproofing, AS 3740, the underlying membrane, puddle flange, and perimeter seals are the true defensive barrier protecting wall framing and subfloors from structural moisture damage.
A shower leaking underneath may also emerge through an adjoining wall, floor or ceiling rather than directly below the fault.
When to stop using the shower
Stop using the shower if:
- water enters a wall, another room or the ceiling below
- the shower base is cracked, moving or unstable
- a ceiling is swollen, sagging or bulging
- moisture is near lights, switches, power points or wiring
- leaking continues while the shower is off.
Keep away from wet electrical fittings and do not touch affected switches, appliances or wiring. Do not stand beneath or puncture a bulging ceiling because saturated material may collapse.
If water continues leaking while the shower is off, close the property’s main water valve only if it is safely accessible. Do not remove the base, open walls, block the waste, repeatedly run the shower or attempt a DIY flood test; these actions can worsen concealed damage.
If the leak is underneath or concealed, our Sydney plumbing team can assess whether it comes from the water supply, waste plumbing, shower base or signs of a waterproofing defect. When you contact us, our team asks a few pre-dispatch questions about whether your bathroom sits on an upper timber level or ground-floor concrete slab, ensuring our technicians arrive with thermal-imaging cameras and non-invasive moisture meters. Fixed Today has supported Sydney homeowners for over 15 years, walking you through every finding with an upfront task breakdown and a $0 call-out fee on approved repairs.