Hot-water extraction, sometimes called steam cleaning, is the deep-clean method most carpet makers recommend. We inject hot water and a cleaning solution into the pile under pressure, then pull it straight back out with a powerful vacuum, lifting the dirt that has worked its way down to the base. Our machine extracts about 95% of the moisture, and the rest dries off within 6 to 7 hours, depending on ventilation.
What hot-water extraction is
Hot-water extraction is a deep clean in four steps: vacuum, pre-spray, agitate, then rinse and extract. We vacuum the carpet dry first to pull out grit and loose soil. Next we spray a pH-balanced pre-treatment onto the traffic lanes and any stains, work it into the pile, and let it dwell so it can break down the oils and ground-in dirt. Then the machine injects hot water under pressure and draws it straight back out, along with the soil it has loosened. The ANSI/IICRC S100 standard, the industry rulebook for cleaning textile floor coverings, classes this as restorative cleaning: the deep one, not the quick surface tidy.
- Hot-water extraction
- Hot water and detergent injected into the pile under pressure and vacuumed straight back out. The deep-clean method, despite the “steam cleaning” nickname; no actual steam touches the carpet.
- The pile
- The upright tufts of fibre you walk on. Most of the dirt in a carpet sits low in the pile, near the backing, where a vacuum cannot reach.
- Pre-spray
- The cleaning solution sprayed on before extraction to loosen oils and ground-in soil, so the rinse can flush them out.
Why it reaches dirt other methods miss
Most of the grime in a carpet is not on top. It is down at the base of the pile, walked there by foot traffic over months. Surface methods, a quick bonnet buff or a supermarket foam, lift the top layer and leave the rest. Hot-water extraction flushes the base, which is why a carpet looks and feels properly clean afterwards rather than just looking better for a fortnight. The Carpet and Rug Institute puts it plainly: extraction removes the oils, embedded dirt and allergens that vacuuming cannot.
Most of the grime in a carpet is not on top. It is down at the base of the pile, walked there over months.
No sticky residue, and fast drying
The old way was to shampoo a carpet and leave it. The problem is the soap. Any detergent left behind stays tacky, and a tacky carpet grabs dirt faster than before, so it greys up again within weeks. Because extraction rinses rather than shampoos, there is no film left to attract soil. We also pull most of the water back out as we go, so the pile is left damp, not soaked. That is the difference between a carpet that is dry by the evening and one that stays wet for a day or more. Over-wetting is the fault we see most often after a DIY job, and it is the one that causes browning and shrinkage.
How often your carpet needs it
For an average home, every 12 to 18 months. That is the interval the Carpet and Rug Institute recommends, and most manufacturers say much the same: Shaw, one of the largest, advises professional extraction every 6 to 18 months depending on traffic. A busy hallway, pets or small children push it to the shorter end. Here is the part people miss. Most carpet warranties require proof of professional extraction cleaning at that interval, so letting it slide can void the cover if a fault ever shows up. Keep the receipt.
When we use a different method
Hot-water extraction is the default, not the only tool in the van. Wool and viscose can shrink or brown if they get over-wetted, so for those we switch to low-moisture dry cleaning, which uses far less water and a different chemistry. The same goes for a job that needs same-day use, an office that cannot shut overnight, say. We match the method to the fibre and the situation, which is the bit a hired machine cannot do for you. If you are not sure what your carpet is made of, we will tell you when we see it.
- Low-moisture cleaning
- A clean that uses much less water than extraction, so wool, viscose and same-day jobs dry in under an hour with no risk of shrinkage.
- Browning
- Brown tide marks that appear when a carpet is left too wet and old dyes or a jute backing wick up to the surface as it slowly dries.
Common questions
Is hot-water extraction the same as steam cleaning?
In everyday speech, yes. “Steam cleaning” is just the common nickname. Technically no steam touches the carpet: the machine heats water and injects it as hot liquid under pressure, then vacuums it back out. The heat helps the detergent work, but your carpet is rinsed with hot water, not steamed.
How long does a carpet take to dry?
For us, 6 to 7 hours, so a morning clean is dry by the evening. We pull most of the moisture back out as we clean, so the pile is left damp rather than wet. Good airflow speeds it along, so we will open a window or leave a fan running on a still day.
Will hot-water extraction damage my carpet?
Not on a normal synthetic carpet. Extraction is the method the makers themselves recommend. The risk is over-wetting on delicate fibres like wool or viscose, which is why we check the fibre first and switch to a low-moisture clean when it is needed. A trained cleaner controls the water; a hired machine left running does not.
Can I just hire a machine and do it myself?
You can, but the National Carpet Cleaners Association advises against it, warning that shop-bought and hired kit carries a real risk of irreversible damage. Hire machines also run cooler and extract less water than ours, which is how DIY jobs end up shrunk, browned or smelling musty. We go into it in professional cleaning versus a hired machine.
Hot-water extraction is what we do most days, across all 33 London boroughs. See our carpet cleaning service, read why regular cleaning protects your carpet’s lifespan, or get a free quote.
