Most mold starts as a small moisture problem nobody noticed. Short answer: inspect your home once a year, ideally before winter or after the spring thaw, and check the roof, attic, crawlspace, doors and windows, vents, HVAC filter area, and sinks. Fix the source of any moisture before repairing the damage. Oregon State University Extension recommends an annual moisture inspection for exactly this reason. Here are 8 places to look.
1. Roof, Flashing, and Pipe Boots
These are the most common places leaks start.
Missing or damaged shingles
Cracked or lifted flashing
Worn rubber pipe boots
2. Gutters and Downspouts
The EPA recommends keeping gutters clean and repaired.
Clogs and overflow
Leaks at joints
Downspouts that dump near the foundation
Check them during rain or snowmelt to catch problems in action.
3. Attic Sheathing, Insulation, and Venting
Wet spots in the attic usually point to a roof leak.
Dark stains on the roof deck
Damp or compressed insulation
Bath fans venting into the attic
A musty attic is covered in Why Your Attic Smells Musty.
4. Crawlspace Pipes, Insulation, and Vapor Barrier
Crawlspaces are a common trouble spot in the Inland Northwest.
Drips and condensation on pipes
Insulation that’s loose or wet
Torn or shifted ground cover
More in why crawlspaces are a mold hotspot.
Questions about your home? Call Us Now: 509.936.3567
5. Exterior Doors, Windows, and Weatherstripping
Gaps let water in and stain the trim.
Soft or stained trim
Failed seals
Condensation between panes
6. Vents and Connections
Dryer, bath, and kitchen exhaust should discharge outside.
Loose connections
Disconnected ducts
Vents ending in the attic
The Department of Energy suggests running a bath fan about 15 extra minutes after a shower.
7. HVAC Filter Area
Mold and dust can build up around filters.
Visible growth
Musty air from vents
Damp filter housings
8. Under Sinks and Vanities
One of the most common hidden leak spots.
Drips at supply lines
Gaps around pipes
Warped cabinet bottoms
Keep indoor humidity below 60%, ideally 30 to 50%, per the EPA.
Frequently Asked Questions
How often should I inspect my home for moisture?
Once a year is a good baseline, according to Oregon State University Extension. Older homes and homes with past water damage may need checks more often, and it helps to look after major storms or snowmelt.
What is the best time of year for a mold prevention check?
Before winter and after the spring thaw. Cold weather brings condensation and ice dams, and thaw is when leaks tend to show up.
What humidity level should I keep inside my home?
The EPA suggests keeping indoor humidity below 60 percent, ideally between 30 and 50 percent.
What are the first signs of a moisture problem?
Musty smells, damp or stained materials, peeling paint, condensation on windows, and visible mold. Wet spots in the attic often point to a roof leak, and drips under sinks point to plumbing.
Want a Professional Home Wellness Check?
A professional check makes sense when you can’t safely reach the roof, attic, or crawlspace, when you’re buying or selling, after a storm or roof repair, or if you notice a musty smell. If you find mold, the EPA says most people can clean about 10 square feet or less themselves. Larger areas go to a professional. See our Home Wellness Check, or ask about the Mold Prevention Membership to put these checks on a schedule.
Our team handles:
Mold inspections and moisture mapping
Mold air testing with laboratory analysis
Crawlspace and attic evaluations
Emergency mold remediation
Mold prevention and protective treatments
Fast action can save your home from extensive mold growth and expensive repairs. Call Us Now: 509.936.3567
Serving: Spokane County, Spokane Valley, Liberty Lake, Post Falls, Rathdrum, Hayden, and Coeur d’Alene
