The short answer
Mold remediation means returning an indoor environment to normal fungal ecology and fixing the moisture that allowed growth. It is not the elimination of all mould, which is not achievable indoors. Containment, not area, sets the cost floor.
Mould work is the most regulated part of this trade in some states and entirely unregulated in others, and the published guidance about which is which is frequently wrong. It is also the area where property owners are most exposed to alarmist marketing.
Two facts do most of the practical work. Remediation without fixing the moisture source is temporary. And containment, negative air and decontamination cost roughly the same whether the affected area is small or large, which is why small jobs carry a minimum charge and why per-square-foot rates fall as jobs grow.
In this section
The mold remediation process, step by step
Eight steps in a fixed order, and why reordering them spreads contamination.
Mold remediation cost, and what actually drives it
$10 to $30 per square foot, and why containment is the cost floor.
What is happening in this area
The widely repeated 10 square foot threshold is EPA guidance aimed at homeowners, not a regulatory limit. Florida separately sets a 10 square foot threshold in statute for when licensed services are required, which is a different thing with different force.
Several states deliberately separate assessment from remediation to remove the conflict of interest in having the same company diagnose and treat. Florida’s licence file, which we pulled in September 2026, showed 3,310 assessors against 3,192 remediators, an almost one-to-one split that reflects exactly that rule.
This section summary is maintained rather than written once. It was last reviewed on 23 September 2026. If something here is out of date or wrong, tell us.