Shower seal broken — what to do? Diagnosis & fix

Almost everyone knows the symptom

You step out of the shower and the bathroom is half flooded. Or the door no longer closes properly and gapes. Or you spot black dots on the rubber. In 9 out of 10 cases, these three symptoms mean the same thing: the shower seal has given up.

The good news: replacing a shower seal is the easiest bathroom repair there is. You need neither tools nor prior knowledge — provided you know which seal you need.

That's exactly what this article is for. We walk through the three most common defect patterns, show you how to recognise them, and guide you to the right replacement seal.

The three most common defect patterns

1. Water drips out at the bottom of the glass

Symptom: after every shower there's a puddle in front of the cabin. Water runs down the lower glass edge and drips onto the bathroom floor.

Diagnosis: the floor seal is worn — usually a lip that has hardened and no longer hugs the glass edge. On walk-in showers it is normally the water deflector.

Fix: replace the floor seal or water deflector. It takes 5 minutes — pull off the old one, click in the new one.

→ View floor seals → View water deflectors

2. Door no longer closes properly or gapes

Symptom: the door swings back slightly when released. Or it does close, but a visible 1–2 mm gap remains between door and fixed panel. Water leaks out sideways.

Diagnosis: the magnetic seal has lost magnetic force or has warped. Door magnets typically last 5–7 years, then attraction noticeably drops.

Test: hold a steel spoon against the inner door edge. Does it stick? Then the magnet is still OK. Does it fall straight off or hang loosely? → replace the magnetic seal.

→ View magnetic seals

By the way: even if the magnetic force is still good, the seal can be warped (heat, pressure). In that case, only replacement helps.

3. Black dots or stripes on the rubber

Symptom: black, sometimes greenish dots or stripes on the white seal. The dots cannot be wiped away.

Diagnosis: mould. It has eaten into the material — surface cleaning no longer works.

Fix: you can try a mould remover, but at this point the seal is usually already porous and should be replaced. In our shower seal mould guide we explain the causes and how to prevent reinfection.

Which seal goes with which defect?

Quick overview:

| Symptom | Likely defective profile | Service life | |---|---|---| | Water at the bottom | Floor seal / water deflector | 3–5 years | | Door doesn't close | Magnetic seal | 5–7 years | | Water leaking sideways | Lip seal at fixed panel or wall abutment | 3–5 years | | Water at the corner | Corner seal 90° | 5–7 years | | Black dots | Material is porous — replace | — |

Why do shower seals fail?

Three main causes:

1. Material fatigue. PVC and TPE harden over time. They lose elasticity and no longer hug the glass. Silicone seals last longer but are more expensive.
2. Cleaning agents. Aggressive bathroom cleaners (especially acidic limescale removers) attack the seal. Milder agents based on vinegar or citric acid are gentler on seals.
3. Mechanical stress. Doors are sometimes slammed with momentum. Magnets handle that, but lips warp over time.

Pro tip: when you replace one seal, replace all seals on the same glass at the same time. They are usually about the same age, and the effort for the second seal is minimal.

What you should do now

1. Identify the defect (table above)
2. Measure the glass thickness — see Determine glass thickness
3. Order the seal or use the configurator to assemble a matching set
4. Replace it following our step-by-step guide

With a bit of luck you'll be done in 30 minutes.

When is it worth calling a pro?

In three cases we would advise against DIY:

• Glass wobbles or hinge is broken. This is no longer a seal problem but a safety-relevant repair — call a glazier or plumber.
• You can't find the original profile shape. On very old or rare brand showers, sometimes only manufacturer-original parts are available — and only via the manufacturer's service.
• Level-floor shower with sealing damage. When not just the seal but the floor-to-wall waterproofing fails, you need a tiler.

In all other cases: go ahead. Replacing a shower seal is the easiest DIY task there is.