How often should I inspect condensation & fogging?
Inspect condensation & fogging at the manufacturer or authority interval, after severe weather or unusual operation, and whenever a documented condition changes.
What this means
Condensation & fogging covers interior moisture, between-pane fogging, frost, and humidity. Relevant observations include Condensation forms inside, Fog is trapped between panes, Ice forms on the inside, Only one room has wet windows, Window trim shows mould-like spots. The correct response depends on age, design, climate, usage, installation, recent work, and the exact manufacturer instructions; these observations narrow next steps but do not prove a failed part.
Safe checks
- Use the exact manual, warranty, local authority, and service history to set the interval for condensation & fogging.
- Add a check after severe weather, renovation, long vacancy, or unusual operation.
- Shorten the interval when a condition is changing or has recurred.
Stop and get help if
- Leave or isolate the area for fire, gas, carbon monoxide, electrical exposure, collapse, sewage, or rapidly spreading water.
- Get qualified assessment when a hidden, growing, recurring, or structural condition is suspected.
Which professional to call
Use a qualified building-envelope specialist when the condition exceeds safe user access or the visible checks do not explain it.
Find the relevant tradeSource and method
This answer combines HomeSOS's structured triage with safety boundaries supported by a public source. It does not replace inspection.
Health Canada: Home safetyReviewed August 12, 2026