Why is mold growing in my home?

Molds are part of the natural environment. Indoors, mold growth should be avoided. Mold is a type of fungus. Molds reproduce by means of tiny spores; the spores are invisible to the naked eye and float through outdoor and indoor air. Mold may begin growing indoors when mold spores land on surfaces that are wet. There are many types of mold, and none of them will grow without water or moisture.

Can mold cause health problems?

Mold spores grow on a wet or damp spot. Molds have the potential to cause health problems. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins). Inhaling or touching mold spores may cause allergic reactions in different individuals. They can be immediate or delayed. These allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis), asthma, irritate the eyes, skin, nose, throat, and lungs of both mold-allergic and non-allergic people. Research on mold and health effects is ongoing.

Where can mold be found?

Indoor mold can be found in several spots in a house e.g.

  • Water damaged areas
  • Crawl spaces
  • Basement
  • Boats
  • Floor joists
  • Attic
  • Automobile
  • Washing machine
  • Walls
  • Drywall
  • Bathroom & showers
  • HVAC
  • Air conditioners
  • Carpet
  • Campers, trailers
  • Painting
  • Mobile homes
  • Clothing
What are the common types of mold?
  • Acremonium
  • Aspergillus
  • Cladosporium
  • Fusarium
  • Mucor
  • Neurospora
  • Penicillium
  • Rhizopus
  • Stachybotrys
  • Trichoderma

* Only testing and analysis will allow you to be sure what strain and type of mold you are dealing with.

How do I get rid of mold?

It is impossible to get rid of all mold and mold spores indoors. The mold spores will not grow if moisture is not present. Indoor mold growth can and should be prevented or controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and fix the water problem. If you clean up the mold, but don’t fix the water problem, then, most likely, the mold problem will come back. If you have health concerns, consult a health professional before starting cleanup.

How can we clean up Mold?
  • Places that are often damp can be hard to maintain completely free of mold. If there’s some mold in the shower or elsewhere in the bathroom that seems to reappear, increasing ventilation (running a fan or opening a window) and cleaning more frequently will usually prevent mold from recurring, or at least keep the mold to a minimum.
  • Fix plumbing leaks as soon as possible.
  • Keep all items completely dry.
  • Scrub off mold from hard surfaces with soapy water and then dry again.
  • It is difficult or sometimes impossible to remove mold from absorbent materials such as ceiling tiles or carpet; as it starts growing in the empty spaces in between the gaps. In such case, it is better to replace the item.
How can I reduce humidity in my home?
  • In case of any leakage, you must respond ASAP. If you can get rid of the issue within 24-48 hours, mold will more than likely not grow on such surfaces.
  • Keep your roof gutters clean.
  • Make sure the ground slopes are away from the building foundation, so that water will not accumulate in and around the foundation.
  • Keep all drain lines unobstructed.
  • Monitor indoor humidity on regular basis and maintain it below 60%.
  • In case of any visible accumulation of moisture on your window, walls or pipes, you must find the source and fix it right away. This condensation is a sign of high humidity level in your house.
  • Use de-humidifiers when needed.
  • Keep your air exhaust systems running while showering, cooking and/or running the dishwasher.
How can I help prevent condensation?
  • Monitor indoor humidity, at an optimum level (30% – 50%)
  • Increase ventilation by keeping your doors and/or windows open
  • Use de-humidifiers or large commercial fans to keep the area dry
  • Cover cold surfaces like pipes with insulation
  • Increase air temperature
What should I do if I suspect hidden mold in my house?

You may suspect mold if the building smells, there has been water damage. It is hard for you to get to the hidden source, as mold may be hidden in places such as back side of dry wall, behind wall paper or paneling, on the other side of the ceiling tiles or under your carpet/ pads, inside walls around pipes, behind furniture, and inside ductwork. If you find it hard to detect the source, it is always a good idea to have a professional do the investigation for you. Often times mold spores are released in the air by disturbing the sites of potential mold growth. If you believe that you may have a hidden mold problem, consider hiring an experienced professional.

What are Biocides?

Biocides are substances that can destroy living organisms. The use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup. Never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia because toxic fumes could be produced. Dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed.

What is Mildew?

Mildew is a growth caused by micro-organisms, whose spores, become molds in a moist and warm environment. They obtain their food from the substances on which they are formed, e.g. the materials of a book. During their growth they produce citric, gluconic, oxalic, or other organic acids, that can damage paper, leather, cloth, etc. Mildews also release color, leading to staining which is difficult to remove. The best way to treat mildew is proper ventilation, relatively low temperature, sunlight, dry circulating air and cleanliness.

What analytical services are provided by NVL Labs for Mold?


  • Fungal ID quantitative – Air-O-Cell, Versa Trap. Bio Cell, Micro 5, Cyclex, Cyclex-D
  • Fungal & Particulates ID Quantification – Air-O-Cell, Versa Trap. Bio Cell, Micro 5, Cyclex, Cyclex-D

Bulk- Non-Viable

  • Fungal ID Tape lift/ Bulk/ Swabs- Direct Exam

Air Viable

  • ID and Quantification of culturable Fungi – *By arrangement only (Min Wait time 7-10 days)

Total Nuisance Dust – NIOSH 500

  • Respirable Dust – NIOSH 600
What Mold Field Services are offered by NVL Labs?
Investigation, Sampling, Services

Do you suspect an indoor air quality (IAQ), mold, or contaminant problem in your building Our staff at NVL Labs is among the most respected and experienced in the Pacific Northwest when it comes to these tough issues. Our investigative approach concentrates on quick problem resolution, common-sense solutions and cost controls. Using industry-accepted sampling and analysis methods, our experienced Industrial Hygienists and Certified Hazardous Materials Manager can tackle your problem and partner with you on solutions.

  • Collect Samples of mold-infected building materials
  • Collect samples of airborne particulate matter
  • Identify (separate) fungi
  • Evaluate environmental factors, including HVAC issues
  • Inspect buildings for water/sewer intrusion using non-invasive moisture detection equipment.
  • Provide inspection report detailing problems, if any, and strategies for resolution
Mold Abatement Management

NVL’s experienced staff can write a protocol for your abatement project that will assist you in preventing the spread of IAQ contamination or exposure to your employees and the public.

  • Present and discuss solution alternatives
  • Provide written Mold Abatement protocols
  • Qualify contractors and assist with bid selection
  • Provide project oversight and quality control evaluations
  • Supply final clearance sampling
Other Indoor Environment Issues
  • NVL also investigates other issues relating to problems with building conditions, and can perform these services and more:
  • Collect samples of standard IAQ gasses (CO, CO2, etc.)
  • Detect levels of formaldehyde (HCHO) in office air from off-gassing lastic and rubber-made office products (for instance, carpet and mastics, and plastic furniture)
  • Determine humidity levels
Unknown Contaminants

NVL often receives calls about unknown causes of worker illness. Many people may have allergies to particulate matter such as animal dander, dust mites and other allergens. Also, other environmental factors, including those surrounding your workplace, may be affecting your employees’ health. NVL can respond quickly, identifying hazards using easy-to-understand terms, and coordinate timely corrective solutions. When scheduling investigations in occupied buildings, NVL can work off-hours or on weekends.

Our Unique background in insurance investigations into unknown contaminants helps us answer questions such as:

  • What is the unknown black particulate on your wall
  • Is the mold damage new, or longstanding
  • Has a contractor contaminated your building with unseen asbestos fibers