Using a steam mop on a carpet
We've all seen the adverts on TV. Lightweight steam mops that the presenter whizzes round the kitchen floor with and the dirt just vanishes. Then they show you the various attachements and microfibre covers and tell you that they are good to use on your carpets.
Steam mops and similar steam cleaning devices certainly have their uses, but on your expensive carpet is not one of them.
There are two main reasons why they are not suitable:
Too much heat can damage your carpet
The first is the amount of heat they generate. Quite simply they are way too hot for carpets and can easily damage the carpet fibres. A high proportion of modern carpets are either synthetic or a mix of wool and synthetic fibres such as Polyproylene, Nylon or Acrylic. The high heat from a steam mop can actually melt these synthetic fibres and cause permanent damage. It's not good for wool fibres either.
I had a desperate call from a customer a while ago saying that his wife had used a steam mop on the high traffic area on the lounge carpet but it had gone black and hard where she had used it - right in the middle of the room. The reason for this was simply the synthetic fibres had melted and fused together forming tiny hard plastic-like beads and trapping the dirt inside. There was nothing that could be done to salvage the carpet and it would have to be replaced. A very expensive mistake.
The cleaning method recommended by most carpet manufacturers is the "Hot Water Extraction" (HWE) method as used by Powerclean Carpets in most cases. This method involves injecting pressurised water into the carpet fibres and immediately extracting it with a powerful vacuum a fraction of a second later. The water is usually heated and contains a PH balanced rinse agent to neutralise any cleaning solutions previously applied. Although the water is heated it is generally to a maximum of 60 degrees. When injected at high pressure into the carpet it sounds like pressurised steam. The spray can also look like steam as it comes put of the pressure nozzles and the process is sometimes mistakenly described as steam cleaning.
Too much water can damage your carpet
The second reason steam mops are unsuitable for carpets is the quantity of moisture they produce. If your carpet is lucky enough to survive the high heat it then has to cope with the deluge of moisture. With steam mops there is no extraction method to immediately remove the significant moisture created by the steam. The microfibre pads do a superficial job of soaking up some moisture and some surface soiling but they become saturated and ineffective in a matter of seconds.
The steam quickly becomes hot water as it cools slightly and it loosens the dirt from the carpet fibres. Gravity then does its work and the resultant dirty water ends up soaking the carpet deep down into the pile (where more accumulated dirt will reside, out of reach of your vacuum cleaner) - and the backing - and the underlay - and the floor. The water simply has nowhere to go.
This now leads on to three more potential problems.
Excessive moisture could lead to shrinkage as the carpet dries - particularly with wool carpets and particularly with hessian backed carpets.
If the carpet remains wet for a long time, especially if the room is poorly ventilated, mould can develop. Mould is not only unsightly but it's a real health hazard.
As the carpet fibres dry they can draw up the dirty water that had pooled underneath. This is known as capillary action or "wicking" and it's a bit like how a lit candle draws molten wax up the wick. The dirty water can rise back up the carpet fibres where it will stay when the carpet eventually dries. It can easily look worse afterwards than before you started due to bringing the hidden layer of dirt up to the surface.
Don't be put off using a steam mop and accessories for other jobs around the house, they can do a great job on some hard surfaces - just not on your carpets!