How steam cleaning works
A steam cleaner heats water to well above 100°C in a sealed tank and releases it as low-moisture steam through a nozzle or attachment. The heat loosens grease and grime and can kill many bacteria and dust mites on contact, particularly when the nozzle is held close for a few seconds. Because the steam is relatively dry, surfaces dry quickly.
Domestic steam cleaners range from handheld units for small jobs to cylinder steam cleaners with a range of tools, and steam mops designed for floors.
What steam cleaning is good for
Steam works best on hard, sealed, heat-tolerant surfaces:
- Ceramic and porcelain tiles and grout in bathrooms and kitchens
- Sealed vinyl and tiled floors
- Hobs, oven doors (outside) and extractor hoods
- Toilets, basins, taps and shower trays
- uPVC window frames, tracks and sills
- Mattresses and upholstery that tolerate moisture, to freshen and reduce dust mites
- Bins, high chairs, pet crates and children's plastic toys
What not to steam clean
The heat and moisture that make steam effective can also cause lasting damage. Avoid steam on unsealed wood and laminate flooring, which can swell, warp and lose their finish – many laminate manufacturers specifically say not to use steam. Oiled and waxed wood, delicate fabrics such as silk and viscose, and leather can be damaged too.
Don't steam natural stone such as marble or limestone without checking, as heat can damage sealers and polish. Keep steam away from sockets and electronics, wallpaper (unless you're stripping it), and anything glued, such as vinyl-wrapped kitchen doors, which can delaminate.
Steam cleaning grout and tiles
Grout is where steam really shines. A narrow nozzle with a small brush attachment, held close and moved slowly along the grout line, lifts grime that's otherwise hard to scrub out. Wipe away the loosened dirt with a microfibre cloth as you go. Steam won't remove deep staining or mould that has grown into the grout, and it won't fix damaged grout – our grout cleaning guide covers the alternatives.
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Steam cleaning upholstery and mattresses
Many fabric sofas and mattresses can be freshened with a steam cleaner, which helps reduce dust mites and odours. Check the cleaning code on the label first – 'W' or 'W/S' codes usually tolerate water-based cleaning, while 'S' means solvent only and 'X' means vacuum only. Use steam sparingly, keep the nozzle moving and let the item dry fully before using it.
Steam freshens but doesn't extract dirt. For a real clean of carpets and upholstery, professional hot water extraction rinses dirt out and removes it – see hot water extraction vs dry carpet cleaning.
Does steam disinfect?
High-temperature steam can kill many bacteria, viruses and dust mites on contact, but the temperature drops quickly once steam leaves the nozzle, and results depend on how long it's held on the surface. Domestic steam cleaners are useful for hygiene but aren't a guaranteed disinfectant in the same way as a product tested to a recognised standard. Our guide to cleaning vs disinfecting explains the difference.
Steam cleaning by professionals
Some professional cleaners use commercial steam machines, particularly for kitchens, bathrooms and grout in deep cleans and end of tenancy cleans. In carpet cleaning, 'steam cleaning' is often used loosely to describe hot water extraction, which is a different process. If a company offers steam carpet cleaning, ask exactly what equipment they use.
