Dry time and mildew risk

What is actually happening

Extraction is a separate stage from cleaning, and it is the stage that decides this. Solution going in suspends the soil; vacuum coming back out takes it away and most of the moisture with it. Weak recovery leaves two problems at once — suspended soil drying back into the fibre, and a pad that stays wet long enough for damp organic material at room temperature to sour. It is also why furniture is never set back down on damp carpet: a sofa blocks airflow completely, and what grows underneath is mildew.

How you prevent it

Airflow is the variable you control after the truck leaves. Ceiling fans and cracked windows bring an eight-hour dry closer to four. If carpet is still wet the next day, say so, because that is a recovery problem rather than a normal outcome.

Because moisture trapped in the padding is where musty odour and mildew begin. Proper extraction pulls most of the water back out in the same pass, leaving carpet damp rather than soaked and drying in four to eight hours. Carpet still wet a day or two later signals weak recovery.