How do I know if a carpet cleaner is good?

Tell one — do they look before they quote

A walk-through before any equipment comes off the truck is not a formality. Fiber identification decides the chemistry, and a burn test or a close look at the pile tells whether it is nylon, polyester, olefin or wool — each takes different handling.

On any home with pets, a blacklight in a darkened room maps what is actually there. Quoting urine work without finding the deposits first is quoting a guess, and it is usually a guess in the company's favour.

The other half of looking first is being told what will not come out. A cleaner who tells you at the start which spots are staying is more useful than one who discovers it after you have paid.

Tell two — can they name their own process

Most companies describe their work in adjectives. Deep. Powerful. Advanced. Those are not a process and they give you nothing to compare.

The IICRC S100 standard describes soil removal as a sequence — dry soil removal, suspension, extraction, drying — with suspension governed by four variables that trade against each other: chemical action, heat, agitation and time.

A company that works to that can tell you where it sits on each of those dials. One that cannot has not decided, which means the decision gets made differently on every job by whoever showed up.

Tell three — the rinse and the dry time

Alkaline chemistry is what releases the oil. Alkalinity left in the pile is residue, and residue is sticky, so the carpet resoils in weeks and the owner blames the cleaning.

The acid rinse is the step that prevents that, and it is the first thing cut on a job priced by speed — because a rinsed and an unrinsed carpet look identical in the driveway. Ask directly whether the rinse is included and what pH the carpet is left at.

Then ask how long it stays damp. Four to eight hours is normal for properly extracted carpet. A carpet still wet the next day was not recovered properly, and that is the condition in which a musty smell develops.

What the price tells you, and what it does not

A very low advertised per-room figure usually covers a fast surface pass with minimal pre-treatment and no dwell time, with the real number arriving once somebody is standing in your living room.

The protection is not paying more. It is getting the complete number before anybody starts, in writing, covering everything you asked for — and asking what the definition of a room is, in feet.