A cracked or leaking shower base means water is escaping at the lowest point of your shower — where the floor meets the walls and the drain — and it’s one of the most common hidden leak sources in a bathroom. Whether it can be repaired or needs replacing depends on the type of base and what’s gone wrong underneath. This guide covers the causes, your options, rough costs, and how a leaking base ties back to your waterproofing.

If you’ve noticed water escaping the base of your shower, or a stain appearing nearby, book an inspection before it works into the floor structure.

How shower bases fail

The base takes more punishment than any other part of the shower — it carries your weight, holds standing water, and sits over the drain. Over time it fails in a few common ways:

  • Cracked base or hob. Movement, flexing underfoot or a knock can crack a base or the raised hob at the front, letting water straight through.
  • Failed seal at the floor-to-wall junction. The silicone where the base meets the walls perishes, and water tracks into the corners.
  • Drain problems. A poor seal around the waste, or the base pulling away from the drain, lets water escape under the floor.
  • Movement in the substrate. If the base isn’t fully supported underneath, it flexes and cracks the surface or the seal above it.

Cracked base vs leaking base — what’s the difference?

They often go together, but they’re not the same problem. A cracked base is a visible break in the surface — you can sometimes see the hairline, or the base flexes when you stand on it. A leaking base means water is getting out, which may be through a crack, or through failed silicone and grout at the junctions and drain with no obvious crack at all. That’s why a leak can be hard to pin down from the surface: the base can look fine while water escapes at a joint you can’t see. (Cracked tiles on the base tell a similar story — see why cracked tiles in your shower are a bad sign.)

Tiled vs acrylic and fibreglass bases

How your base is built changes the fix:

  • Tiled bases are waterproofed with a membrane under the tiles, then finished with grout and silicone. Most tiled-base leaks come from failed seals or a failed membrane rather than the tiles themselves — which often means a reseal, or a rebuild if the membrane has gone.
  • Acrylic and fibreglass bases are a single moulded tray. These can crack or craze with age and movement, and a cracked tray usually needs repair or replacement rather than resealing.

Knowing which you have is the first step in working out whether it’s a quick fix or a bigger job.

Repair or replace: which do you need?

The right call comes down to the cause and the extent of the damage:

  • Reseal — if the base is sound and the leak is from perished silicone or grout at the junctions and drain, a reseal stops it, usually with no tiles or tray removed. The most common and most affordable outcome.
  • Repair — a cracked acrylic or fibreglass tray can sometimes be repaired, depending on the location and severity of the crack.
  • Rebuild or replace — if the waterproofing under a tiled base has failed, or there’s structural damage, the shower base needs to be rebuilt and re-waterproofed to standard. See our shower rebuilds service.

You can’t always tell which from the surface, which is exactly what an inspection is for.

How much does it cost to fix a shower base?

Cost depends entirely on the cause. A reseal of the base junctions is one of the more affordable shower repairs — far less than a rebuild. Repairing a cracked tray sits in the middle. Rebuilding a tiled base where the waterproofing has failed is the most involved, because the base has to be stripped, re-waterproofed and re-tiled.

The biggest factor in the final bill is how long the base has been leaking. Caught early, it’s often a reseal. Left to run, water gets into the floor structure and you’re paying to repair rot and framing as well. Fixing a base leak early is one of the cheapest ways to protect the floor beneath your bathroom.

How a leaking base ties back to your waterproofing

The base is where waterproofing works hardest, because water pools there before it drains. When the membrane or the seals at the base fail, water doesn’t just sit — it runs into the floor, the wall frame and, in two-storey homes, the ceiling below. That’s why a “small” base leak is worth taking seriously: it’s the part of the shower most likely to cause structural damage if it’s ignored.

Don’t let a base leak reach the floor

A leaking shower base only gets more expensive the longer it runs. Get a shower base inspection and quote from Leaky Showers and we’ll tell you whether it’s a reseal, a repair, or a rebuild.

Frequently asked questions

Can a cracked shower base be repaired, or does it need replacing?

It depends on the base. A cracked acrylic or fibreglass tray can sometimes be repaired depending on where and how bad the crack is. A tiled base that’s leaking because the waterproofing has failed usually needs rebuilding. An inspection confirms which applies.

Why is my shower base leaking but I can’t see a crack?

Many base leaks aren’t through a visible crack at all — they’re through perished silicone or grout at the floor-to-wall junctions or around the drain. Water escapes at a joint you can’t easily see while the base looks fine.

How much does it cost to fix a leaking shower base?

Resealing the base junctions is one of the cheaper repairs; repairing a cracked tray costs more; rebuilding a tiled base where the waterproofing has failed costs the most. The longer it’s left, the higher the cost, because water damage to the floor gets added in.

Is a leaking shower base serious?

It can be. The base is where water pools, so a leak there is one of the most likely to reach the floor structure, wall frame and the ceiling below in two-storey homes. It’s worth fixing early.

Can a leaking shower base be fixed without removing the tiles?

Often, yes. If the base is sound and the leak is from failed silicone or grout, a reseal fixes it without removing tiles. If the waterproofing under the base has failed, a rebuild is needed.