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Pasadena (91101–91107) & Altadena (91001) • San Gabriel Valley

Mold Inspection in Pasadena & Altadena, CA

Independent, certified professional mold inspectors serving the Pasadena, CA 91101, 91103, 91104, 91105, 91106, 91107 and Altadena, CA 91001 communities. Test-only — we never sell remediation to ensure unbiased recommendations.


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Your Friendly Test Only Inspector - Tanjun Mold Inspections

Pasadena & Altadena Mold Inspection & Testing Professionals

Check your historic or modern Pasadena (91101–91107) or Altadena (91001) home for mold, moisture, and air quality issues. Schedule your Test-Only inspection.

Call Your Test-Only Inspector (818) 964-1533

Local Housing & Environmental Insights • 91101–91107 & 91001

Pasadena & Altadena Housing Trends & Mold Risk Factors

Historic Craftsman Homes, Foothill Geography & Aging Envelopes

Characterized by historic architectural treasures and unique foothill geography, Pasadena and Altadena present distinct moisture challenges compared to newer Southern California developments. While residents enjoy the timeless charm of Pasadena’s Bungalow Heaven or Altadena’s sweeping mountain views, the aging infrastructure of many local properties creates specific vulnerabilities to moisture retention, wood decay, and indoor air quality issues.

A primary concern across the 91101–91107 and 91001 zip codes is structural aging and material fatigue. Many iconic Craftsman, Victorian, and mid-century ranch homes built between the late 1800s and 1960s lack modern vapor barriers, sub-slab membranes, and contemporary waterproofing systems. Over decades, settling foundations and weathered exteriors can develop micro-fissures that allow seasonal moisture to penetrate deep into wall cavities.

Post-Fire Environmental Changes (2025 Eaton Fire) Properties in the foothill zones continue to adjust to structural and environmental changes following the January 2025 Eaton Fire. Near the burn perimeter, water deployed during structural firefighting or containment efforts may have pooled in unvented crawl spaces or saturated subfloors, occasionally acting as a catalyst for hidden microbial growth.
Altered Watershed Runoff & Hydrostatic Pressure The 2025 wildfire stripped stabilizing vegetation along the San Gabriel Mountain slopes, causing winter rainstorms to shed water down hillsides more aggressively. This increased surface runoff elevates hydrostatic pressure against older concrete foundations, driving moisture through porous basement walls and historic stone retaining slabs.
Undetected Structural & Roof Envelope Compromises Wind-driven embers from previous fire events can cause subtle micro-damage to roofing membranes, flashing seals, and attic vents — allowing subsequent rainwater to leak into attic insulation and slowly saturate plaster ceilings.
Historic Plumbing Vulnerabilities Established neighborhoods like the Arroyo Seco or Garfield Heights frequently feature original galvanized, brass, or early copper plumbing systems that can develop minor pinhole leaks behind dense lath-and-plaster walls.
Substandard Crawl Space Ventilation Many classic Pasadena raised-foundation homes feature early wooden crawl space vents that have been painted over or blocked over time, restricting airflow and trapping earth-borne humidity beneath historic floorboards.
Dense Historic Tree Canopy Impact Mature oak, deodar cedar, and jacaranda trees provide shade but limit sunlight hitting rooftops and exterior siding, extending drying times after rain events and promoting localized moss, rot, or mold growth.
Arroyo Seco & Canyon Microclimates Properties situated near the Arroyo Seco, Eaton Canyon, or Millard Canyon experience higher evening humidity and longer dew-point windows than the open plains of the Los Angeles basin.
Hidden Wall Cavity Growth (Lath & Plaster) Unlike modern drywall which shows water stains relatively quickly, dense historic lath-and-plaster walls can conceal interior moisture and mold colonies for extended periods before visible staining breaks through to the surface.
Subfloor Wood Decay Unmitigated moisture trapped within unsealed crawl spaces breeds wood-destroying fungi, potentially leading to structural dry rot in original floor joists and buckling historic hardwood flooring.
Basement & Cellar Efflorescence Common in older Pasadena estates, white powdery mineral deposits on subterranean brick or concrete walls indicate that moisture is actively migrating inward from the surrounding soil.
Kitchen & Antique Bathroom Venting Failures Early 20th-century floor plans rarely included mechanical exhaust fans in bathrooms or laundry nooks, forcing steam to settle on ceilings or collect behind heavy wooden cabinetry.
Window Frame & Sill Rot Original wood-framed windows are highly susceptible to moisture trapping when exterior paint seals fail, allowing rainwater to soak into the frame and degrade surrounding structural wood.

Check your historic Pasadena or Altadena home from fire-suppression water damage and environmental moisture risks.

Your Friendly Technical Interpreter. Test-Only

Mold Inspection & Testing Services in Pasadena & Altadena

Home Mold Inspections

Mold Inspections

Visual inspections that may include moisture content readings, humidity measurements, and checking common areas where moisture intrusion is often a risk. Includes a detailed written report with findings and recommendations.

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Air & Surface Lab Testing

Lab Testing

Our professional mold samples are analyzed by an AIHA-accredited laboratory, with standard results typically available within 2 business days. Rush processing, including next-business-day reporting, is available for an additional fee.

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Indoor Air Quality Testing

Indoor Air Quality Testing

Evaluate airborne mold spores, species detected, and ambient air quality. When appropriate, wall cavity air sampling may also be performed.

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Post-Remediation Clearance

Post Remediation Clearance Testing

PRV (Post Remediation Verification) or Clearance Testing services involve independent verification and testing to ensure mold remediation was successfully completed.

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Real Estate Mold Inspections

Pre-Sale Home Inspections

A vital aspect for performing due diligence during real estate transactions, Tanjun Mold Inspections offers pre-purchase and pre-sale inspections for buyers, sellers, and agents in Pasadena, Altadena, and nearby communities.

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Water Damage & Moisture

Water Damage Assessments

Promptly identify hidden moisture and potential mold growth after leaks, floods, or plumbing failures to minimize damage.

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Residential Inspection & Testing - Starting Prices

Prompt turnaround times, detailed reports, and friendly, easy-to-understand explanations.

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Standard Home Mold Inspection

$350+

Base fee starting at $350 for homes up to 1,500 sq. ft.

AIHA Lab Testing Samples

$95

Per air or surface sample analyzed by an AIHA-accredited lab.

Indoor Air Quality (IAQ) Only

$440+

Starting at $440 for targeted air quality only visit & lab report.

Post Remediation Clearance

$550+

Starting at $550 for independent PRV visual, moisture & air testing.

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Schedule Your Pasadena & Altadena Mold Inspection

If you’re buying a home, noticing a musty odor, or dealing with past water damage or fire-suppression moisture, a professional mold inspection can help you make informed decisions.

Professional mold inspections and Indoor Air Quality Testing in Pasadena & Altadena, CA can help you identify potential risks early on to maintain a healthy indoor environment — with accurate, reliable results you can trust.

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EDUCATOR. NEIGHBOR. SPECIALIST.

Why Customers Choose
Tanjun Mold Inspections

Educator

Your Friendly Tech Interpreter

Your Friendly Test Only Inspector - Tanjun Mold Inspections

"Takes Time to Teach..."

We take time — to provide a friendly and understandable explanation of the inspection findings and the technical details of the report to customers — who are not lab techs.

Neighbor

Your Local Small Business

Your Friendly Small Business - Tanjun Mold Inspections

"Opposite of Corporate..."

Since we're not a chain or franchise — we are not under pressure to meet corporate sales quotas. Instead, we invest in the time and personal attention needed for each unique job.

Specialist

Your Certified Lab Service

Your Certified Lab Service - Tanjun Mold Inspections

AIHA Certified

All air and surface samples are logged and processed utilizing trusted, independent AIHA-accredited laboratories with secure chain-of-custody protocols. Reliable data — means informed decisions.

AIHA LAP Accredited Laboratory Logo Badge

Samples are sent to an AIHA (American Industrial Hygiene Association) accredited laboratory that specializes in environmental microbiology.

ENVIRONMENTAL MICROBIOLOGY


Lab Reports

What Kind of Information is Contained in Lab Reports?

They provide very technical and detailed information that we analyze and summarize so that it is more friendly and useful to our customers.

The lab analysis will report on any mold found, the amount and the mold types detected (such as Aspergillus/Penicillium, Stachybotrys, Chaetomium, Ulocladium). We determine whether the sample indicates:

  • NORMAL FUNGAL ECOLOGY An indoor environment that reflects a normal fungal ecology
  • SETTLED SPORES An indoor environment that is contaminated with some settled spores
  • ACTUAL GROWTH An indoor environment that is contaminated with actual mold growth and associated spores
FUNGAL DICTIONARY

What are common mold types found indoors?

Select a mold genus below to review its environmental characteristics and common indoor substrates.

Lab technician holding petri dish with mold growth analysis
Alternaria

Alternaria is one of the most common molds and is abundant worldwide. This genus contains around 40 to 50 different species, only a few of which are commonly found indoors. Alternaria spores are easily dispersed through the air by wind. Alternaria can grow on a variety of substrates indoors when moisture is present.

Cladosporium

Cladosporium is an abundant mold worldwide and is normally one of the most abundant spore types present in both indoor or outdoor air samples. This genus contains around 20 - 30 different species. Cladosporium produces dry spores that are formed in branching chains. Spores are released by twisting of the spore-bearing hyphae as they dry. Thus, the spores are most abundant in dry weather. Cladosporium can be found anywhere indoors, including textiles, bathroom tiles, wood, moist windowsills, and any wet areas in a home. Some species of Cladosporium grow at temperatures near or below 0(C) / 32(F) and can often be found on refrigerated foodstuffs and even frozen meat.

Penicillium / Aspergillus

Penicillium / Aspergillus are two separate genera of molds that are so visually similar that they are commonly discussed together as a group. Together, there are approximately 400 different species of Penicillium / Aspergillus. Penicillium / Aspergillus produce dry spore types that are easily dispersed through the air by wind. These fungi serve as a food source for mites, and therefore can be dispersed by mites and various insects as well. Penicillium / Aspergillus are found throughout the home. They are common in house dust, growing on wallpaper, wallpaper glue, decaying fabrics, wallboard, moist chipboards, and behind paint. They have also been isolated from blue rot in apples, dried foodstuffs, cheeses, fresh herbs, spices, dry cereals, nuts, onions, and oranges.

Chaetomium

Chaetomium is a common mold worldwide. This genus contains around 80 - 90 different species. Chaetomium spores are formed inside fruiting bodies. The spores are released by being forced out through a small opening in the fruiting body. The spores are then dispersed by wind, water drops, or insects. Chaetomium can grow in a variety of areas indoors, but is usually found on cellulosebased or woody materials in the home. It is very common on sheetrock paper that is or has been wet.

Stachybotrys

Stachybotrys is ubiquitous in nature. This genus contains about 15 species. Stachybotrys produces wet slimy spores and is commonly dispersed through water flow, droplets, or insect transport, less commonly through the air. Stachybotrys is common indoors on wet materials containing cellulose such as wallboard, jute, wicker, straw baskets, and other paper materials.

Pasadena (91101–91107) & Altadena (91001) • Local Mold Insights

Pasadena & Altadena Mold Inspection FAQ

Why are older Pasadena and Altadena homes more susceptible to mold?

Many Pasadena and Altadena homes built before the 1970s lack modern vapor barriers and use lath-and-plaster construction, which can trap moisture from aging galvanized pipes or original window seals, leading to hidden mold growth.

How does canyon runoff affect Pasadena and Altadena properties?

Properties near Eaton Canyon or Millard Canyon face higher hydrostatic pressure from hillside runoff. During winter rains, this water can seep into crawl spaces, basements, or through older concrete slabs that lack contemporary moisture mitigation.

Can the morning condensation in Pasadena and Altadena cause mold?

Condensation has the potential to contribute to mold growth. Pasadena and Altadena's foothill geography traps cold air at night, leading to heavy morning condensation on single-pane windows. This localized moisture can cause mold colonization on wooden sills and drywall casings.

FAQ

Mold Frequently Asked Questions

Our Credentials


MICRO Certified Mold Inspector CMI # 86294

InterNACHI (International Association of Certified Home Inspectors) Certified Mold Inspector

Member # NACHI25081826  |  Certificate # 1755634505

IAC2 Certified, IAC2 Mold Certified (International Association of Certified Indoor Air Consultants)

Certification ID: IAC2-95070

Friendly Communications. Lab Backed Data.

Our Process

Tanjun Mold Inspections performing- Professional Performing Visual Inspections

Visual Inspections

We start with performing a visual inspection of the property, focusing on areas where there may be water damage, moisture issues or suspected mold growth.

Tanjun Mold Inspections - Advanced Tools for Taking Environmental Measurements

Environment Readings

With the help of specialized tools we may take environmental readings such as Moisture Content (MC) or humidity levels in order to identify any potential issues.

Tanjun Mold Inspections - Lab Analysis for Mold Samples

Lab Testing & Analysis

Surface and Air samples may be recommended depending on the inspection findings or customer concerns. Such samples are sent to an AIHA Accredited Lab that specializes in identifying and analyzing mold.

Tanjun Mold Inspections Providing a Comprehensive Findings and Recommendations Report

Findings & Recommendations

Once all of the data is collected, we provide a report of our findings. If a mold growth problem is identified, a Remediation Protocol is outlined.

CONTACT US

Our Process - Advanced Tools for Taking Environmental Measurements

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PHONE Call (818) 964-1533

EMAIL tanjunmold@gmail.com

SERVICE AREAS

Los Angeles County, CA

Ventura County, CA



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