A carpet is the biggest filter in your home. Every day it catches what comes in on shoes, paws and the air: skin scales, pollen, pet dander, bacteria and the house dust mites that live on all of it. Vacuuming clears the surface. A professional hot-water clean flushes out the load that has settled deep in the pile, which is the part that matters if anyone in the house has allergies or asthma.
What actually builds up in a carpet
The main culprit is the house dust mite. Allergy UK describes them as tiny creatures about a quarter of a millimetre across that live on the flakes of dead skin we all shed, and they do well in warm, humid homes. They settle in bedding, carpets, soft furnishings and clothing. It is not the mite itself that sets people off; it is their droppings, which dry to a fine dust and lift into the air when the carpet is disturbed. Alongside them the pile collects pet dander, pollen walked in from outside, mould spores and ordinary bacteria. A carpet can hold a surprising weight of dust before it even looks dirty.
- House dust mite
- A microscopic relative of the spider, around 0.25mm long, that feeds on shed human skin and lives in carpets, mattresses and soft furnishings.
- The allergen
- Not the mite but its droppings. These dry to a fine powder that becomes airborne and triggers allergy and asthma symptoms when breathed in.
- High-filtration vacuum
- A vacuum with a HEPA or sealed filter that traps the fine allergen dust instead of blowing it straight back out into the room.
Why it affects your breathing
House dust mite allergen is one of the most common indoor triggers there is. The NHS lists dust mites, pets and mould among the usual causes of allergic rhinitis, the sneezing, blocked nose and itchy eyes that a lot of people mistake for a cold that never clears. For anyone with asthma or eczema, the same allergen can flare the symptoms, and the effect tends to run all year rather than with the seasons. If your hay-fever feeling never quite lifts in winter, the carpet and the bed are the first two places to look.
How a professional clean removes the load
Hot-water extraction works by flushing. We inject hot water and a cleaning solution into the pile under pressure, then draw it straight back out with a strong vacuum, and the mites, the droppings, the skin scales they feed on and the trapped allergens come out with the water. Allergy UK notes that washing at 60°C or above kills dust mites, which is why bedding goes on a hot wash. You cannot put a fitted carpet through the machine, but lifting out the mites and the food source they depend on cuts the living population right back. And because the carpet is rinsed rather than shampooed, no sticky residue is left to grab the next round of dust.
Lifting out the mites and the food source they depend on cuts the living population right back.
Carpet or no carpet, if you have allergies
Here is the honest version. For a serious dust-mite allergy, Allergy UK suggests reducing carpet in the bedroom and laying a washable hard floor, because no amount of cleaning makes a carpet completely mite-proof. For most homes, though, a carpet is fine, and arguably helpful: it traps particles and holds them down, out of the air you breathe, as long as you empty that filter often enough. In practice that means vacuuming with a high-filtration machine through the week and a professional deep clean once or twice a year. Doing one without the other is half a job.
How often it is worth it
For most homes, every 12 to 18 months, the interval the Carpet and Rug Institute recommends. Bring it forward to every 6 to 12 months if someone has allergies or asthma, if you have pets, or if there is a baby or toddler spending the day down on the floor, nose to the pile. They are the ones who breathe in most of what the carpet gives back, so they are the reason to keep on top of it.
Common questions
Can dirty carpets make allergies worse?
Yes. Carpets hold house dust mites and their droppings, a leading indoor allergen the NHS links to allergic rhinitis and to worse asthma. The allergen lifts into the air when the carpet is walked on or vacuumed. Clearing the load with a professional deep clean reduces what you end up breathing in.
Does carpet cleaning kill dust mites?
It removes most of them. Hot-water extraction flushes the mites, their droppings and the skin scales they live on out of the pile. Allergy UK notes that 60°C kills mites, so the heat and the physical extraction together knock the population right back, though no clean leaves a carpet permanently mite-free.
How often should I clean carpets if someone has asthma?
Every 6 to 12 months for a professional clean, rather than the usual 12 to 18, with regular high-filtration vacuuming in between. Keeping indoor humidity down helps as well, since dust mites need moisture in the air to thrive.
Is having a carpet bad for allergies?
Not necessarily. A carpet traps allergens and holds them out of the air, which can help, but only if you clean it properly and regularly. For a severe dust-mite allergy, Allergy UK suggests a washable hard floor in the bedroom. For most people, regular cleaning is enough.
We clean carpets for plenty of London homes with allergy and asthma sufferers in them. See how hot-water extraction works, read the wider benefits of keeping carpets clean, or get a free quote for your home.
