What Are the Signs of Mold in a Newly Purchased Home?
Last updated October 25, 2026
The short answer
Visible Signs of Mold
Mold often appears as black, green, or white patches on surfaces. Look closely at bathrooms, basements, and areas around windows. Mold can grow behind wallpaper, under carpets, and inside walls, so a small spot may indicate a larger problem.
Water stains or discoloration on ceilings or walls are common clues. Peeling or bubbling paint often means moisture is trapped underneath. Warped wood, such as baseboards or window frames, can also point to ongoing dampness that supports mold growth.
- Black spots on grout or caulk
- Green or gray patches on drywall
- White fuzzy growth on wood or fabric
- Dark streaks on ceilings near vents
- Stains that reappear after cleaning
Musty Odors and Air Quality
A persistent musty smell is one of the strongest indicators of hidden mold. Even if you cannot see mold, a damp, earthy odor means moisture is present. The smell often intensifies in closed rooms or after rain.
If you notice a musty scent, try to locate the source. Check under sinks, around toilets, and in crawl spaces. Sometimes the odor comes from the HVAC system, where mold can grow on coils or in ducts. A professional inspection can help find the exact source.
- Musty smell in closets or storage areas
- Odor that returns after airing out the room
- Damp smell near windows or exterior walls
- Scent coming from vents or air registers
Health Symptoms You Might Notice
Mold exposure can cause sneezing, coughing, watery eyes, or skin irritation. If you or your family feel unwell after moving in, mold might be the culprit. Headaches, fatigue, or trouble breathing can also be related to indoor mold.
These symptoms may be worse in certain rooms or when the heating or cooling runs. Keep track of when symptoms appear. If they persist, see a doctor. A medical professional can determine if your symptoms are linked to mold or another cause.
- Sneezing or runny nose
- Itchy or red eyes
- Coughing or wheezing
- Skin rash or dry patches
- Headaches or dizziness
When to Call a Professional
If you see visible mold, smell a musty odor, or notice health symptoms, act quickly. Small patches you can clean yourself, but larger areas or hidden mold need professional help. The pros can identify the type of mold and the moisture source.
For a thorough assessment, a water damage inspection can map out moisture issues. If mold is widespread, structural drying and dehumidification may be necessary. Local water damage pros in Detroit can guide you through the process. Policies vary, and your insurer decides what is covered.
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Call (313) 766-2970 any time, day or night, and describe what happened.
Call Now (313) 766-2970Frequently asked questions
Can I clean mold myself?
Small patches on hard surfaces can be cleaned with soap and water. Wear gloves and a mask. If the area is larger than a few feet or if mold is in drywall, call the pros. Never mix cleaning products.
How do I know if mold is toxic?
Any mold can trigger allergies, but black mold is often a concern. A mold professional can test samples to identify the species. If you feel unwell, see a doctor. Testing is not always necessary for cleanup.
Will mold go away on its own?
No. Mold will keep growing as long as moisture is present. You must fix the water source and dry the area. Without that, cleaning only removes surface mold. A professional can help address the root cause.