Common indoor species
- Penicillium thrives on water-damaged drywall and fabrics.
- Aspergillus spreads quickly through ducts and HVAC equipment.
- Cladosporium often shows up on damp wood, carpet, and upholstery.
Mold detection at a glance
Quick reference points to confirm mold faster and avoid costly damage.
Where growth accelerates
- Moisture + humidity + organic material gives mold everything it needs.
- Watch drywall seams, attic sheathing, crawl spaces, and basements first.
- Condensation on windows or ductwork can fuel hidden colonies.
Testing toolkit
- Air sampling measures airborne spore levels and indoor air quality.
- Swab and tape lifts confirm the species on visible growth.
- Dust sampling captures a longer history of exposure inside the home.
Start with these detection essentials
Use these guideposts to confirm what you are facing and choose the right course of action.
Common Mold Types
Pictures, colors, and health considerations for the species most often found indoors.
Read guideMold Testing Methods
When to use air, swab, ERMI, or dust sampling—and how to read the results.
Read guideWhere Mold Hides
Identify growth on drywall, insulation, carpets, HVAC systems, and more.
Read guideMold in Rental Homes
Document issues, communicate with landlords, and protect your rights as a tenant.
Read guideBrowse detection topics
Dive into detailed walkthroughs for specific detection scenarios, surfaces, and questions.
Common Types of Mold Found In Your Home
Many different mold types can grow in your home, and they can cause different health issues. Types of mold found in homes, health issues caused by each type, ...
Open pageMold Testing Methods
Learn about the different types of mold testing including air sampling, swabs, ERMI, tape, dust, and wall cavity testing. Know which is right for your home.
Open pageMold on Common Building Materials
Learn how to identify mold on drywall, baseboards, insulation, windows, and other common materials inside your home. Expert advice from Lookmold.
Open pageMold in a Rental Property: What You Can (and Should) Do
Learn how to identify, document, and address mold in a rental unit. Expert tips for both tenants and landlords on prevention, communication, and cleanup—without legal confusion.
Open pageNext steps after detection
Move from confirmation to action with remediation, prevention, and local resources.
Mold Remediation Guide
Learn when DIY is safe, how pros remove mold, and what a complete remediation includes.
Plan remediationMold Prevention Tips
Control moisture, ventilation, and maintenance tasks to keep mold from coming back.
Prevent future moldMold Remediation by State
Check your state's mold laws, insurance rules, and vetted cleanup specialists.
Find local infoTop Moldiest States
See how climate and housing factors create hotspots—and what to do if you live in one.
View rankingsIn-depth guide: Mold Detection
Prefer the full walkthrough? Read the comprehensive article below.
To detect mold in your home, look for visible signs (discoloration, fuzzy growth), musty odors, and moisture problems like water stains or condensation. Common locations include bathrooms, basements, crawlspaces, attics, and areas around HVAC systems. Professional mold testing methods include air sampling, surface swabs, tape lifts, and ERMI dust analysis. If you suspect hidden mold behind walls or in ductwork, a licensed mold inspector can use moisture meters and thermal imaging to locate it. The EPA recommends testing whenever you smell mold but can’t see it, or after water damage events.
FAQ: Mold Detection
How do I know if I have mold in my house?
Look for visible discoloration on walls, ceilings, and floors, musty or earthy odors, and signs of moisture such as water stains, peeling paint, or condensation. Mold often hides behind drywall, under carpets, and inside HVAC systems. A professional mold inspection with air sampling can detect hidden mold you cannot see.
Can you smell mold without seeing it?
Yes. Mold produces microbial volatile organic compounds (MVOCs) that create a distinctive musty, earthy smell. If you can smell mold but cannot find visible growth, it may be hidden behind walls, under flooring, or inside ductwork. The EPA recommends professional testing whenever you detect a mold odor without a visible source.
Do I need a professional mold inspection?
You should hire a licensed mold inspector if the affected area exceeds 10 square feet, if you smell mold but cannot locate it, after any significant water damage event, during real estate transactions, or if occupants are experiencing unexplained respiratory symptoms. Professional inspectors use moisture meters, thermal imaging, and lab-analyzed air samples for accurate results.
How much does mold testing cost?
Professional mold testing typically costs $200 to $600 depending on the number of samples taken and the size of your home. A basic visual inspection with 2-3 air samples runs around $300-$400. ERMI dust testing and more comprehensive multi-room sampling can cost $500 or more. Home test kits cost $10-$50 but are significantly less accurate.
What should I do if I find mold?
For small areas under 10 square feet on non-porous surfaces, you can clean with white vinegar or hydrogen peroxide while wearing an N95 mask and gloves. For larger areas, mold on porous materials like drywall or carpet, or any suspected toxic mold, hire a licensed mold remediation professional. Always identify and fix the moisture source first to prevent regrowth.
Don’t guess. Detect. Small leaks, humidity spikes, or musty odors can snowball into a major remediation project. If you notice signs of black mold, document what you find and bring in a licensed inspector when you need expert confirmation.