Where mould grows · 1 min read
Where mould grows in commercial buildings
The rooms, systems and building details that produce mould most reliably — and why HVAC is usually part of the story.
Mould needs moisture, a food source and time. Commercial buildings supply all three in predictable places.
The usual suspects
HVAC systems. Condensate trays, cooling coils and insulated ductwork stay damp and dark. Once growth starts, the system distributes spores to every room it serves.
Wet areas. Bathrooms, showers, kitchens and laundries with light-duty extraction fans that cannot keep up with use.
External walls. Cold surfaces in heated rooms attract condensation, particularly behind furniture and joinery where air does not move.
Ceiling voids and plenums. Roof leaks, sweating pipes and condensation above tiled ceilings go unnoticed for months.
Below grade. Basements, car parks and ground floors on slabs with moisture issues.
Vacant or closed spaces. Rooms left closed with the air-conditioning off over a holiday period.
Why it matters for treatment
Surface cleaning addresses what can be seen. Airborne diffusion reaches into voids, plenums and ductwork where the source often sits. In most buildings the two are needed together.