How Saguenay is built
- Before 1961 26%
- 1961–1990 49%
- 1991–2000 9%
- 2001 or later 16%
Why mold shows up in Saguenay homes
Saguenay gets about 5,343 heating degree-days a year and has a winter design temperature of −28.9°C, according to NRCan's HOT2000 climate data for Jonquière. On cold days, exterior corners, closets on outside walls and window frames get cold enough for condensation, which is where mold usually starts in Saguenay houses.
Of Saguenay's 48,955 houses (single-detached, semi-detached, row houses and duplexes), 26% were built before 1961 and 75% before 1991, according to the 2021 Census. Older basements without a moisture barrier and houses that were air-sealed without adding ventilation are common trouble spots.
When sampling is worth it
- You smell mustiness but can't find the source.
- After a leak or flood, to check that cleanup worked.
- Before buying an older house with signs of past water damage.
If you can see mould, you usually don't need a test to know it's there; you need to fix the moisture and clean it up properly.
Quebec has a voluntary standard for handling mould in homes (BNQ 3009-600, 2020); no province has a mandatory residential mould standard.
Choosing a tester and lab
Ask any Saguenay tester which lab analyzes their samples, and look for one accredited under AIHA's EMLAP program for environmental microbiology. Pair sampling with a ventilation and humidity assessment, which finds the cause.
Ventilation and humidity assessments in Saguenay · Our mold and indoor air quality guide
Mold and air quality testing in Saguenay: common questions
How much does mold testing cost in Saguenay?
Plan on about $300–$600 for a typical sampling visit (a September 2026 planning range); lab fees for extra samples add to that.
Do I need a test if I can see mould?
Usually not. Visible mould needs cleanup and a fix for the moisture source. Testing helps most when you suspect mould you can't see.
Is there a legal mould limit for homes in Canada?
No. Health Canada sets no numerical limit; its guidance is to control moisture and clean up mould. Quebec has a voluntary handling standard.