Do Your Carpets Need To Be Cleaned?

Figuring out if your carpet needs to be cleaned is not always easy. Sometimes it may be difficult to tell whether we are looking at a relatively clean surface or an evenly dispersed layer of dirt throughout. If nothing catches our eye such as a spot or stain, we probably won’t give our floors’ cleanliness a second thought. But is appearance a good indicator of a carpets’ cleanliness? Is dirt the only thing we should be concerned about? According to scientific studies, maybe not.

The Studies Show…

In a study done by The University of Arizona, they looked at bacteria levels on the bottom and inside of people’s shoes. They found the sole of the average person’s shoe has about 421,000 bacteria. The inside of their shoe has about 2,887. In the words of Professor Kelly Reynolds, “We walk through things like bird droppings, dog waste, and germs on public restroom floors, all of which are sources for Ecoli.” What the researchers also found was that, out of those 421,000 units of bacteria, 90% of them ended up on the floor of people’s homes. Because the pathogens remain on the underside of the shoe, it’s almost like walking through a public restroom then right onto your living room floor! If we walk around our house just 4 times in a day, in 365 days we will have made 1,460 trips through the house. Giving dirt and bacteria 1,460 chances to spread throughout our home. And for each additional person, this number increases. Pets also contribute to bacteria levels by walking on fecal matter outside the house or in their own litterbox inside the home. 

There was a study done by two scientists; Dr. Robyn C. Miranda, a microbiologist and food safety expert and Dr. Donald W. Schaffner, a microbiologist and former W.H.O committee member. They tested the 4 most common household surfaces to see how quickly bacteria transferred from the contaminated surface to food. The scientists took several samples of wood, tile, carpet, and stainless steel. They disinfected them and then applied bacteria to each sample. Food was dropped from varying heights onto the contaminated samples. The scientists then tested how many bacteria transferred from the floor samples to the food. They found that bacteria transferred onto food instantly. They also found that the longer the food was on the surface the more bacteria transferred onto it. However, out of the 4 samples, the carpet did a better job of retaining bacteria than the others. The scientists saw drastically lower transfer rates from carpet to food as opposed to the hard surfaces. This means that when contaminated, carpets do a better job of keeping those contaminates off of other surfaces. 

They state: “We observed lower transfer rates (∼0.2%) when the transfer was from carpet to food. Carpet may promote less bacterial transfer because of bacterial attachment to or infiltration of absorbent carpet fibers.” Therefore; since carpet is absorbent it can hold more dirt and bacteria than a hard surface can without showing it or causing a problem. Because of this, carpet can be cleaned less frequently than other floor surfaces.

How Often Should You Clean Your Carpets?

With so many ways for bacteria to get into our homes, should we be concerned? Perhaps not, so long as we keep them clean. According to the leading carpet manufacturer Shaw Industries; carpets should be cleaned (depending on the amount of traffic in your home) on average once every 12 to 18 months. They say at the very minimum carpets should be cleaned once every 24 months. MOHAWK also states in their warranty “once every 18 months”. The CRI (Carpet and Rug Institute) which is a trade association dedicated to the scientific study of carpeted flooring and its effect on the environment, advises carpet to be cleaned professionally every 12 to 18 months as well. 

For general upkeep, the CRI advises vacuuming at least once a week. Be sure to go slowly in order to remove all the dirt and debris. Vacuuming should be a slow and methodic process. It may not feel like much, but it makes a tremendous difference. For spots and stains, blot with a clean white rag. If a cleaning product is used it should first be CRI certified and tested for colorfastness in an inconspicuous area. Small handheld machines such as the SpotBot are a great option for spot cleaning as long as sufficient time is taken to extract and ensure proper drying. However, the CRI says that the smaller machines are not a substitute for periodic deep cleaning. Professional cleaning services once every 18 months are still needed to ensure that the carpets stay thoroughly cleaned!


The take away from this is that regardless of appearance, carpets still retain an abundance of unwanted matter. In a year’s time, carpets will have been traveled across thousands of times and have accumulated millions of bacteria in addition to dirt and allergens. Even if it doesn’t look dirty, it should still be cleaned to ensure proper cleanliness and good health for everyone living in your home.

At ALL CLEAN!, LLC, we cannot promise that you or your family members won’t become ill. There are so many other factors that contribute to the health and wellbeing of you and your family. But we can promise that our hot water extraction method is capable of killing and removing dirt and bacteria that are found deep within your carpet fibers. Give us a call today. We look forward to hearing from you.