What's actually on your shower glass
Soap scum is the dull, slightly greasy film left by soap, shampoo and body oils. Water marks are the white spots minerals leave behind when drops dry on the glass. Mould is the black that grows along the silicone seals, in the corners and in the grout next to the screen.
Each one shifts with something different, so look closely before you start. A cloudy film that comes off on your fingernail is scum; spots that stay put are usually minerals.
Check the shower glass coating before any product
Some shower screens come with a factory coating that helps water run off. If yours has one, the manufacturer's care sheet says what's safe on it, and abrasive scourers or harsh cleaners can wear it away. On any glass, skip steel wool and scouring powders: they scratch, and a scratched screen holds grime faster.
How to clean shower glass, step by step
Air the room
Open the window or turn on the extractor fan before you start, and keep it going until the bathroom is dry.
Wet it warm
Rinse the glass with warm water from the shower head to soften the film.
Apply a mild cleaner
A little dishwashing liquid in warm water lifts soap scum. For water marks on plain glass, white vinegar diluted with water softens the minerals. Let it sit briefly.
Work it with a soft sponge
Use the non-scratch side of a sponge in small circles, top to bottom. An old toothbrush gets into the frame, the hinges and the track along the bottom.
Rinse well
Wash everything off with clean water, so no cleaner dries into a fresh film.
Dry it
Pull a squeegee down the glass in overlapping strokes, then buff the edges with a microfibre cloth.
Mould on the shower seals and grout
Small black spots on silicone and grout can be cleaned as they appear, and Tenancy Services points to white vinegar for mould. Wear gloves and eye protection, and wipe it rather than scrubbing it dry: Consumer NZ warns against dry-brushing mould, because it can release spores into the air.
If the black is deep in the silicone and won't shift, it's probably in there for good. Consumer NZ says mould in grout and silicone is almost impossible to remove once it gets in, so the seal may need replacing or the grout redoing. For large areas of mould, Health New Zealand says to get advice from a mould removal specialist.
The two shower products that never go together
If a mould spray contains bleach, don't use vinegar or an acid cleaner on the same surface: Consumer NZ warns that bleach and vinegar create toxic chlorine gas, and bleach must not be mixed with ammonia or other cleaners either. Use one product, rinse it off completely, and keep the window open or the fan running. If someone feels unwell after breathing fumes or swallowing a cleaner, the National Poisons Centre is on 0800 764 766; in an emergency, call 111.
Keep shower glass clear for longer
The habit that does the most is a squeegee after every shower. It takes the water off before the minerals can dry onto the glass.
Then deal with the steam. Consumer NZ suggests running the extractor fan while you shower and for about 10 minutes afterwards, and wiping water off the walls. In a rental, the healthy homes standards mean the bathroom should have an extractor fan venting outside, so use it.
Shower glass you can manage, and glass to hand over
Worth doing yourself
- A squeegee after every shower.
- A weekly wipe with dishwashing liquid and warm water.
- Diluted vinegar on light water marks on plain glass.
- Small mould spots on the seals as soon as they show.
Where a cleaning business earns its keep
- Months of soap scum and mineral build-up across a whole screen.
- Shower glass as part of a deep or end of tenancy clean, along with the grout and tiles.
- Tracks and frames packed with grime.
- A bathroom where you'd rather not handle strong products yourself.
Our advice on cleaning shower glass for good
Clean it once properly, then keep a squeegee hanging in the shower and use it every time; that habit does more than any product. If the screen has years of build-up or the seals have gone black right through, send it as part of a deep clean, and plan to replace the silicone rather than expecting anyone to scrub it white.