· Michael Blair
Mould spores are present in every building at background levels. What matters is active growth indoors, which requires a moisture source. Fix the moisture and the growth stops; treat the growth without the moisture and it returns.
Scale determines the approach
Small areas of surface growth on a hard non-porous surface — bathroom grout, a window sill — are cleaning, not remediation.
Larger areas, growth on porous materials such as drywall or insulation, or anything inside a wall cavity, is remediation territory with containment.
Testing, and when it helps
If you can see it, testing usually adds little — you already know you have a problem, and the remedy does not change much with the species.
Testing is useful to confirm suspected hidden growth, to establish a baseline before and after remediation, or in a dispute.
- Visible growth on hard surfaces: clean it
- Porous materials affected: remove them
- Anything above a modest area: professional remediation
- Find and fix the moisture source first, always
- Post-remediation verification if the job was large
The moisture source is the actual job
Remediation that does not identify why the material was wet is incomplete. In Middle Tennessee that source is frequently a crawl space, a bathroom fan venting into an attic, or a slow plumbing leak.
A remediation quote that does not address the cause should be questioned before it is accepted.
What to be sceptical of
Free inspections from companies that also sell remediation, very large quotes generated from an air sample alone, and dramatic language about toxic black mould.
An independent assessor with no remediation to sell is worth the fee when the numbers get large.