A smell, a stain or a change in a surface usually comes before any visible growth when there is mold in your Denver, CO home. Because mold needs moisture, look first for water: a leak, humidity or condensation. Work through the checklist below, and if you want an assessment, use Call Now and an independent provider serving 66 ZIP codes around Denver will answer.
What mold looks and smells like
- Water stains on ceilings and walls, even if they look dry
- Warped, soft or swollen drywall, baseboards and flooring
- A musty, earthy or damp odor, often stronger when the air is still
- Bubbling, peeling or discolored paint and wallpaper
- Spots or patches that are black, green, gray, white or orange on walls, ceilings, grout or wood
Where to look first
- In basements, crawl spaces and attics
- Around the air handler, drain pan and registers
- Around windows, in corners and on exterior walls
- Under sinks, behind toilets and around tubs and showers
- Behind furniture pushed against cold walls
Clues that point to moisture
- Humidity above about 50 percent on a hygrometer
- Recent leaks, floods, roof damage or plumbing repairs
- Dripping, hissing or running water noises
- Higher than normal water bills
- Condensation on windows and cold pipes
Health symptoms and what to do
Some people react to mold with sneezing, irritation or breathing difficulty. These symptoms can have many causes, and this website does not diagnose them. If someone is unwell, talk to a doctor, and let the provider know about any health concern so the work can be planned safely.
What to do when you find it
- Keep the area closed and avoid blowing air across it
- Do not disturb it, scrub it dry or paint over it
- Find and fix the water source if it is safe to do so
- Call a provider for an assessment if it is larger than a small patch
- Take photos and note the date and location
A checklist for this week
- Check under sinks, around the water heater and behind toilets for leaks
- Look at the attic and crawl space for stains or damp insulation
- Take photos of any stain you find and note the date
- Run bath and kitchen fans and check they vent outside
- Clean gutters and extend downspouts
Myths and facts
- Myth: if you cannot see it, it is not there. Fact: hidden mold can show up as smell or stains.
- Myth: painting over mold seals it. Fact: growth continues underneath.
- Myth: a dehumidifier cures mold. Fact: it helps control humidity but does not remove existing growth.
- Myth: bleach solves mold. Fact: EPA does not recommend it routinely and it does not fix moisture.
- Myth: black mold is always the most dangerous. Fact: color does not identify mold, and the response is the same.
Why the first 48 hours matter
Drying wet materials within 24 to 48 hours is the advice in many guidelines, since after that mold can begin to grow on drywall paper, wood and insulation. The chance of growth falls with fast extraction, dehumidification and removal of materials that cannot be dried.
Mold and moisture terms explained
- HEPA: a high-efficiency filter that captures very small particles
- Moisture source: the leak, humidity or condensation that keeps materials wet
- Negative air machine: a fan with a HEPA filter that pulls air out of containment
- Relative humidity: the amount of water vapor in the air as a percentage; many guides aim for under about 50 percent
- Containment: plastic barriers and an airlock that keep spores in the work area
- IICRC S520: the standard for professional mold remediation
- Antimicrobial or biocide: a chemical product that EPA does not recommend as routine for mold cleanup
What shapes the written scope
Jobs that look similar can differ greatly in scope. A written scope should state which of these factors applied to your property and what each of them added to or took out of the work.
Ask the provider to separate the assessment, the removal, the drying and the rebuild, and to say who is responsible for finding and repairing the water source.
- Size of the affected area and how many rooms or levels it touches
- Containment needs, access and occupants who are sensitive or at risk
- Whether sampling or independent verification is wanted or required by a lender, insurer or landlord
- The moisture source and whether it has been repaired
- Materials involved: drywall, insulation, wood framing, carpet, ductwork
Safety, health and what the standards say
Moisture in the building is the root of any mold problem. EPA guidance on mold in homes calls for fixing the moisture problem, cleaning or removing contaminated material and drying the area, while the IICRC S520 standard sets out professional remediation practices such as containment and verification. This website reports what those sources recommend; it makes no medical claims and promises no health outcomes.
Anyone with allergies, asthma, weakened immunity or another health concern should speak to their doctor and stay out of the work area. The area is isolated from the rest of the home, and workers wear respirators, gloves and eye protection.
Questions to ask a mold remediation company
- How will you dry the structure and what readings show it is dry?
- Who will verify the result, and is that person independent of the work?
- What will you contain, remove and clean, and what stays?
- Where is the moisture coming from, and who fixes it?
- What is in the written scope, and what is excluded?
- How will you control spores and dust in the rest of the house?
When to call a professional
Get in touch when the affected area is bigger than roughly ten square feet, when mold is in the HVAC system or inside walls, when the water source is unknown, when contaminated water flooded the area or when anyone in the home has health concerns. Call Now at the top of the page puts you through once you describe what you found: an independent remediation company covering your ZIP code confirms your address and assesses the property in person.
What this means for a home in Denver
Denver's semi-arid climate means mold usually comes from a specific moisture source (leaks, flooding, ice dams, condensation, basement seepage) rather than constant humidity. Older brick bungalows and Denver Square homes often have basements and crawl spaces with window-well leaks.
Evaporative (swamp) coolers in older homes can add indoor moisture. Spring snowmelt, summer hail on the Front Range, and winter ice dams are common sources of roof leaks. Use these local details when you compare advice, and ask any provider how they apply to your house.
Getting help in Denver and nearby cities
Mold Remediation Denver connects you with independent mold remediation companies covering 66 ZIP codes in Denver, Colorado: 80201, 80202, 80203, 80204, 80205, 80206, 80207, 80208, 80209, 80210. Requests also reach providers serving Wheat Ridge, Commerce City, Englewood, Arvada and Westminster. Coverage is confirmed address by address.
Describe what you found through Call Now, at the top of the page. The provider confirms your address, assesses the moisture and writes the scope down for you.
Keep reading
Related pages for Denver homeowners: Mold Testing: When It Helps and When It Does Not; How to Prevent Mold: Humidity and Moisture Control; Does Bleach Kill Mold?; Mold and Home Insurance: Questions to Ask. For the area list, see the service areas page.
Common questions about signs of mold in your denver home
How can I tell if it is mold?
Look for musty smell, stains and a damp area. A professional can confirm and find the source.
Is mold always visible?
No. It can grow inside walls, under floors and in attics, and show up as smell or stains.
Should I test it?
Often the priority is fixing moisture. Testing helps in specific situations.
What humidity prevents mold?
It helps to keep indoor humidity under about 50 percent.
Can I clean it myself?
Small surface patches on hard materials, following EPA guidance. Larger or porous areas need a professional.
How fast does mold spread?
It can start within a day or two on wet materials.