A shower usually leaks for one of a handful of reasons: perished silicone, cracked or missing grout, failed waterproofing, a leaking base or hob, a leaking screen, or a plumbing problem behind the wall. The tricky part is that they can all look the same from the outside — water on the floor, a stain on the ceiling, or mould that won’t quit. This guide runs through each cause, how to spot it, and how it’s fixed, so you know what you’re dealing with.

Want it diagnosed properly? Book a leak inspection and we’ll find the exact source — usually without removing a single tile.

1. Perished or cracked silicone

The most common cause. The silicone seals around the base, corners and screen perish over time — they shrink, crack and lift away from the tiles, letting water seep behind them. If your silicone is cracked, peeling or permanently mouldy, it’s likely the culprit. The fix is usually a reseal, or a careful re-silicone of the joints. Recurring mould on the silicone is a classic warning sign — see black mould in the shower.

2. Cracked or missing grout

Grout is porous and moves with the building, so it cracks and crumbles over time. Once it fails, water tracks behind the tiles and keeps the wall damp. Missing or crumbling grout is a frequent leak source — more in can missing grout cause leaks. The fix is usually regrouting combined with resealing (grout alone rarely stops a leak).

3. Failed waterproofing membrane

Behind your tiles sits a waterproof membrane that’s meant to keep water off the structure. When it fails — through age, movement or a poor original installation — water gets past it and into the wall, floor and rooms beyond. This is the most serious cause, because surface repairs won’t hold. See our shower waterproofing guide. The fix is a rebuild and re-waterproofing to standard.

4. A leaking shower base or hob

The base takes the most punishment and is where water pools before it drains. A cracked base, a failed seal at the floor-to-wall junction, or a poor seal around the drain all let water escape at the lowest point. See leaking shower base. Depending on the cause, this is a reseal, a repair, or a rebuild.

5. A leaking shower screen

Water can escape past a screen through worn seals, cracked silicone or gaps from a dropped or misaligned screen — pooling on the floor outside. See shower screen leaking. New seals and silicone often fix it, but a screen leak and a shower leak can look identical, so it’s worth confirming the source.

6. A plumbing leak

Not every “shower leak” is the shower. A leaking waste pipe, drain connection or supply line behind or beneath the shower sends water into the wall or ceiling too — and that’s a plumber’s job, not a resealer’s. A quick clue: a leak that appears only while showering points to the shower; one that continues when it’s not in use points to plumbing.

How the source is found

Because water travels and appears away from where it escapes, pinpointing a leak takes the right approach rather than guesswork — a close inspection of the seals, grout, base and screen, flood testing to reproduce the leak, and moisture meters to map where water is sitting. More in our guide to shower leak detection. Once the source is confirmed, you know whether you need a reseal, a rebuild, or a plumber.

The reassuring part

Most leaking showers — the large majority we see — are caused by failed silicone or grout with the waterproofing still intact, which means they can be resealed without removing tiles, in a day, for a fraction of a renovation. Only when the waterproofing itself has failed is a rebuild needed. Either way, the leak won’t fix itself, and it gets more expensive the longer it runs.

Get your leak diagnosed

Don’t guess which of these it is — get it confirmed. Book a leak inspection with Leaky Showers across Brisbane, the Gold Coast and Logan, and we’ll find the source and tell you exactly what it needs.

Frequently asked questions

Why is my shower leaking?

Usually one of six causes: perished silicone, cracked or missing grout, failed waterproofing, a leaking base or hob, a leaking screen, or a plumbing leak. They can look identical from the outside, so the source needs to be diagnosed.

How do I find where my shower is leaking from?

A specialist inspects the seals, grout, base and screen, flood tests to reproduce the leak, and uses moisture meters to map where water is sitting. This locates the source without removing tiles.

Is my shower leaking or is it a plumbing problem?

A leak that appears only while showering and stops afterwards usually points to the shower seal or waterproofing. One that continues when the shower isn’t in use points more to a plumbing pipe. Detection confirms which.

Can a leaking shower be fixed without removing the tiles?

In most cases, yes. If the leak is from failed silicone or grout and the waterproofing is intact, a reseal fixes it with no tiles removed. A rebuild is only needed when the waterproofing membrane has failed.

Will a leaking shower get worse?

Yes. Water reaching the structure causes rot and damage that compounds over time, so the repair only grows more expensive the longer it’s left.