Inspection Prévention Moisissures

Mold requires moisture. Identify and eliminate all moisture sources: leaks, condensation, groundwater, and high humidity areas.

1. Check for plumbing leaks under all sinks, behind toilets, and at water heater

2. Inspect roof for leaks — check attic for water stains

3. Check windows for condensation — persistent condensation indicates humidity problem

4. Inspect basement walls and floor for moisture or efflorescence

5. Check HVAC condensate drain — should be clear and draining

6. Look behind furniture on exterior walls (hidden mold growth area)

7. Inspect crawl space for moisture, standing water, or soil moisture

8. Check exterior grading — should slope away from foundation

- Slow plumbing leaks hidden behind walls

- Roof leaks dripping into wall cavities

- Condensation on cold surfaces (windows, pipes, exterior walls)

- Groundwater seeping into basement

- HVAC condensate not draining properly

- Moisture trapped behind furniture on exterior walls

Indoor humidity should stay below 60%, ideally 30-50%. Bathrooms, kitchens, and laundry rooms need exhaust ventilation.

1. Check indoor humidity level with a hygrometer — should be 30-50%

2. Verify bathroom exhaust fans are functional and ducted to exterior

3. Check kitchen range hood — should exhaust to exterior

4. Verify dryer vents to exterior

5. Check HVAC system — AC helps dehumidify in summer

6. If using a dehumidifier: verify it drains properly and is sized for the space

7. Check for adequate air circulation in closets and behind furniture (leave gap from exterior walls)

- Indoor humidity consistently above 60%

- Exhaust fans not ducted to exterior (blow moisture into attic)

- No exhaust fan in bathroom

- Dryer vented indoors

- Poor air circulation in closets and corners

- HVAC oversized (short cycles, doesn't dehumidify)

Common mold locations: bathrooms, basements, attics, crawl spaces, around windows, under sinks, and behind appliances.

1. Inspect bathroom caulk and grout — look for black or dark spots

2. Check under sinks and around toilets for musty smell

3. Inspect attic — look for mold on roof sheathing (especially north-facing)

4. Check basement walls and corners — especially where walls meet floor

5. Inspect around windows — look for mold on frames and sills

6. Check behind washer and dryer

7. Inspect HVAC ducts and air handler — open access panel and look inside

8. Smell test — musty odor indicates hidden mold

- Black mold on bathroom caulk and grout

- Musty smell from HVAC system (mold on coils or in ducts)

- Mold on attic sheathing (from exhausting into attic or inadequate ventilation)

- Hidden mold behind drywall from slow leaks

- Mold around windows from persistent condensation

- Mold in crawl space from exposed soil moisture