Carpet steam cleaning: what to expect

Carpet steam cleaning is not steam, despite the name. The industry term is hot water extraction, and it describes the process much better.

Hot water and a detergent solution are injected into the pile under pressure, agitating the soil away from the fibre. A vacuum head then pulls the water, the detergent and the soil back out in the same pass.

That last part is the whole point. Anything that puts moisture into a carpet without extracting it is shampooing, and shampooing leaves residue that attracts dirt faster than before.

It is the method most leases mean when they require professional carpet cleaning, and the one most manufacturers specify to keep a warranty intact.

A typical visit has five stages, and skipping any of them shows up in the result.

1. Vacuuming first, thoroughly. Dry soil removed now is soil that never turns to mud.

2. Spot treatment of individual stains, matched to what caused them.

3. A pre-spray over traffic lanes, left to dwell for ten minutes.

4. Extraction, in overlapping passes, working back towards the door.

5. A final dry pass over the same area to pull out as much water as the machine will take.

That last dry pass is the one that gets skipped when somebody is running behind, and it is the difference between carpet dry in four hours and carpet damp overnight.

Four to six hours in good conditions, and up to twelve in a closed-up house in winter.

The variables are airflow, humidity and how much water went in. A truck-mounted machine extracts more than a portable one and cuts drying time accordingly.

You can walk on damp carpet in clean socks almost immediately. Keep shoes off, and keep furniture off until it is properly dry.

Open windows and run fans if you have them. A dehumidifier does more than a heater, because warm wet air with nowhere to go simply moves the moisture around.

A stain that disappears and reappears three days later has not been re-stained. It has wicked.

The spill soaked through the pile into the backing and the underlay. Cleaning removed what was in the fibre, and as the carpet dried, the rest travelled back up with the moisture.

It is most common with drinks, pet accidents and anything sugary, and it is not a sign of a bad clean. It usually resolves with a second treatment once the carpet is fully dry.

Tell your cleaner about any spill that soaked in. Knowing what is underneath changes the treatment, and a heavier extraction on that patch usually prevents the wicking outright.

An honest answer here saves everyone a disappointing afternoon.

That last row is the one people find hardest to hear. Wear is not soiling: the fibre no longer reflects light evenly, and no amount of carpet steam cleaning restores it.

A good technician will tell you which of these you have before starting, not after.

Most providers price per room, with a minimum charge covering the first two or three.

Expect $35 to $60 a room, with hallways and stairs quoted separately. Stain treatment and deodorising are usually extras of $30 to $50.

A whole-house booking is cheaper per room than one or two, for the same reason every service is: the setup happens once. Our carpet steam cleaning service lists the current rates.

For an end of lease job, book the carpets and the exit clean together. Carpets are done last, after the property is empty, and one visit is cheaper than two.

Most of what makes a stain permanent happens before a professional is ever called. This is worth putting on the fridge.

SPILL — first 60 seconds

1. BLOT, never rub. Rubbing drives it into the backing
   and frays the fibre. Press, lift, repeat with a dry cloth.

2. Work from the OUTSIDE IN, or you spread the ring.

3. Cold water only. Heat sets protein stains — milk,
   egg, blood — permanently.

4. No supermarket stain spray on wool or a stain you
   cannot identify. Residue attracts dirt and some
   products bleach.

5. Weigh a dry towel down on it and leave it an hour.

6. Tell the cleaner what it was. Treatment depends
   entirely on the substance.

Step one is the one nobody follows. Rubbing feels like effort and is the single most common way a spill becomes a stain that no amount of carpet steam cleaning will lift.

A loose rug needs a different treatment from the floor it is sitting on, and cleaning it in place is usually the wrong answer.

Wool, silk and viscose rugs can shrink, bleed dye or lose their backing under hot water extraction. Viscose in particular marks permanently when it gets wet, and it is sold as "art silk" or "bamboo silk" in a great many rugs.

A good technician will check the fibre before touching it, and will say when a rug needs to go to a specialist for a wash bath instead.

Cleaning a rug in place also traps moisture against the floor underneath. On timber that means cupping, and on carpet it means a damp patch that smells within a week.

Every twelve to eighteen months for an ordinary household, and every six to nine months with pets, children or a smoker in the house.

Most carpet manufacturers require professional cleaning at defined intervals to keep a warranty valid, and many ask for the receipts. It is worth checking yours before deciding to stretch it.

Vacuuming between visits does more for a carpet's life than anything else. Most carpet wear is grit cutting the fibre from underneath rather than staining on top.

A doormat at every external door removes a surprising share of that grit before it ever reaches the pile.

Move what you can. Small furniture, floor lamps, bins, toys and anything on the floor of a wardrobe you want done.

Heavy items are usually cleaned around, or moved and returned onto protective tabs. Ask which, because it changes what is finished at the end.

Point out the stains and say what caused them. "Something red, about a year ago" is genuinely more useful than leaving the technician to guess.

Plan the day so the rooms can be left alone. Carpet steam cleaning is one of the few services that works best when everybody is out of the house until it dries.

A carpet that smells is almost never a carpet problem. The odour is bacterial, and the bacteria are living on something that soaked through the pile into the underlay.

That is why deodorising sprays fail. They mask the smell for a few days and change nothing underneath, and the odour returns with the next humid week.

Pet urine is the usual culprit. It needs an enzyme treatment applied heavily enough to reach the same depth the spill did, then time to work before extraction.

In bad cases the underlay has to be replaced. A technician can usually tell with a moisture meter and a torch, and it is better to know before paying for three cleans that were never going to fix it.

Smoke is the other one. It settles into every soft surface in a room, so treating the carpet alone rarely resolves it.

Most providers offer a protective coating after cleaning, and opinions on it vary more than they should.

What it does is real but modest. It coats the fibre so spills bead rather than soak in, which buys minutes to blot before a spill becomes a stain.

What it does not do is make carpet stain-proof, and it wears off in traffic lanes within a year or two.

It is worth it on a new light-coloured carpet, in a house with children or pets. It is rarely worth it on a rental you are about to leave.

Dry compound cleaning spreads an absorbent powder into the pile and vacuums it out. It is quick, it leaves the carpet usable immediately, and it suits a commercial floor that cannot be closed.

It does not reach the base of the pile, and it is not what a lease means by professional cleaning. For a home, extraction gets more out.

Encapsulation sits in between and is popular for maintaining offices between deeper cleans. It is a maintenance method rather than a restorative one.

For a domestic property once a year, carpet steam cleaning is the method worth paying for. The others have their place, and that place is usually a floor that has to stay open.