Rug Steam Cleaning

Steam cleaning a rug is an efficient way to remove dirt, embedded debris and unsightly spots. The name itself, however, is somewhat of a misnomer. Many professionals refer to "steam cleaning" by the more accurate, hot-water extraction (HWE).
A basic steam-cleaning machine consists of a water-based cleaning solution pumped through a thin hose to a spray nozzle that directs the solution onto a carpet or rug. The mixture reacts quickly, dislodging soil from the carpet fibers. The water and dirt are vacuumed away a brief moment later.

Prepping the Room

Before any carpet cleaning can occur, the room must be ready. Contrary to what many think, the room does not have to be empty. Some pieces of furniture do not need to be moved at all. Computer desks with lots of wires should be left alone; the same holds true for television wall units with DVRs, sound systems and other gadgets. Pianos and china closets full of dishes fall into the same category.
Move furniture like the dining room table and chairs to one side of the room while the other side is cleaned. Then, move the furniture to the other side of the room while the opposite side is cleaned. This will save a lot of unnecessary crowding in another room.

Pre-Spray and Spot Clean

Traffic lanes are the areas that see the most feet. Entryways are an easy target, as is the area in front of the couch. Using a pressure sprayer, mist (don't soak) these areas with a traffic-lane cleaner.
Carpet-cleaning suppliers offer a variety of solutions for the various carpets on the market. Enzyme cleaners are popular for greasy areas (such as by the kitchen door in restaurants).
Spot clean heavy spots that need extra help, such as gum. Solvents are good for removing gum, but must be rinsed from the carpet--which is why it makes sense to spot clean them before the steam machine comes along.

The Basics

Once the carpet is prepped, it is time to perform the actual steam cleaning (or hot water extraction). Mix the steam-cleaning concentrate with hot tap water in a bucket before pouring it into the machine; this is especially important if using a powder concentrate.
Start with the furthest spot in the room and work backwards toward the door. Make sure to overlap the wand strokes, since the spray may not reach the full distance across the wand head. Continue until the entire rug has been cleaned.

Wand Technique

If the steam machine has a separate wand (as opposed to an all-in-one-unit), there are a couple of tricks that can be done with the wand for more efficient cleaning.
If the rug is relatively clean, extend the wand away from you. Press the trigger to release solution and pull the wand toward yourself. When the wand is back to its starting spot, stop spraying. Take a dry pass over the same area by pushing the wand away. When the wand is at the top of the stroke, move it over to the right or left for the next cleaning stroke. Overlap about 2 inches with the previous stroke. When an area of about 10 square feet is completed, take a few dry passes over the carpet.
For heavily-soiled carpets (such as traffic lane areas), start the stroke at the bottom, pushing the wand away. Begin spraying immediately. When the wand is at the top of the stroke, pull back while still spraying. This will use more solution, but will also give extra cleaning power. When about 10 square feet is completed, give several dry passes to extract the extra moisture.

Quick Tips

An easy mistake to make while steam cleaning is to over-wet the carpet or rug. Never hold the wand in the air to "spray down a section."
Dump the waste tank water in a toilet, rather than in a sink (as carpet fibers can clog the pipe), and never in a storm drain, as it is bad for the environment.

Re-Setting the Room

When the steam cleaning is finished, replace the furniture. Place a square of aluminum foil under wooden and metal furniture. This prevents furniture stain from seeping into the carpet, and prevents moisture from warping the wood; for metal, the foil prevents rust stains from penetrating the carpet fibers. Place long strips of aluminum foil under furniture that sits flush to the floor.
Plastic, such as the wheels on a desk chair, will not harm the carpet and does not need any protection.
Do not place mats or carpets of any kind on top of a wet carpet. This will hold moisture against the carpet and cause mildew to grow.