Mould & Moisture Consulting - Microbiology Services

What is Mould & What causes it ?

Mould are part of a large number of fungal species , that grows on plant or animal matter .

It commonly forms a downy or furry coating in a variety of colours on the surface it grows on, this makes it easily identifiable to the human eye.

Mould produce spores profusely which can give it a dusty texture, and causes it to spread quickly and readily throughout the property as spores become airborne

The Worst Offenders

Poor ventilation

Un-flued gas heaters

Drying washing inside

Rising Damp

Unvented Clothes dryer

Absence of Extractor Fans in Bathrooms & Kitchens

Disabling (or refusing to use) Ventilation systems (HVAC)

Lack of Natural Light


Health Implications?

Some species can cause upper respiratory tract symptoms, including a wheezing cough and asthma like symptoms, in sensitised people.

It is also important to note that not all mould species are toxic to human health.

Immunocompromised is the key word here – not everyone will get sick!

Tenant vs Landlord – Who must do what ?

  • Tenants must keep the property clean and tidy including keeping the property in a condition that doesn’t encourage mould and damp. This includes keeping the house well aired, and removing mould as soon as it appears.
  • Landlords – All properties must be in a reasonable state of cleanliness before being rented out.  This includes being free from mould and dampness.
  • Landlords are generally responsible for damp if it’s caused by structural defects or leaky pipes.
  • Landlords should also consider options that allow a tenant to ventilate the house while keeping it safe and secure

Best Practice

  • Firstly, not all black mould is toxic black mould- many species have a black appearance
  • Its imperative that ALL Occupants are well informed about the causes of dampness and mould in houses (lifestyle factors included)
  • Guidance should be provided to prevent situations where mould has grown out of control
    • Keeping the property ventilated
    • Remove mould when it appears
    • Determine if the source of dampness is due to gas heaters, cooking (or other lifestyle factors)
  • Occupants MUST understand that all homes can have small amounts of mould, it is everywhere and cannot be eliminated completely.
  • When a mould issue persists in the property it is prudent to investigate to determine if lifestyle factors are the cause or if there is a underlying issue such as a water leak at the property
  • Don’t do Nothing – The critical aspect is to be able to demonstrate and follow an appropriate process when an issued is raised, being able to identify if it’s harmful, understand what are the contributing factors and of course how to deal with it.

Mould Testing Auckland, Christchurch & Northland

All Clear provide comprehensive on-site mould testing in Auckland, Christchurch, Whangarei and Northland. Our scientific team are experts in helping to diagnose severity and next steps. We offer an impartial mould testing & analysis service, and are committed to providing independent and pragmatic advice.

Help is just a phone call or email away on 093920000 or 

Frequently Asked Questions

  • Just because mould is black, does not mean it is toxic black mould (Stachybotrys). There are over 100000 types of mould, many of them do have a black appearance.
  • The most well-known toxic black mould species is Stachybotrys, it produces toxins that can have carcinogenic and immunosuppressive effects on your health.
  • Some mould species such as Chaetomium, Penicillium, Aspergillus and Cladosporium are known to cause a variety of health effects ranging from allergic reactions, triggering asthma or causing pulmonary diseases.
  • The key component to remember is that typically only people that are susceptible to disease or immunocompromised are more likely to be affected than healthy adults. Not everyone will get sick from mould.

Mould needs a variety of factors to grow in your house when they are combined, it creates an ideal environment for mould growth.

These factors are:

  • Moisture
  • Mould needs moisture to grow. Look at the causes for increased moisture in your home. These causes can be, a lack of ventilation, water leaks, unvented dryers, gas heaters water leaks etc.
  • Darkness
  • Mould cannot grow under UV light (sunlight). Keeping curtains closed, and the house dark will allow mould to grow
  • Warmth
  • Most mould species needs 20°C to grow. Heating up your home increases mould growth.
  • Oxygen
  • Mould will not grow in areas that lack oxygen.
  • Food Source
  • Mould will feed of organic materials in your home such as gib, wood, carpet and even paint.

Have a look around in your home, do you have a situation where all of these factors are at play?

  • Vinegar, a basic household product is effective to remove mould. Dilute the vinegar as it can damage paint and spray it on the affected area, leave it for a couple of hours and clean up.
  • Do not make use of bleach, as bleach only kills the surface mould, the remaining mould growth will return over time.
  • The only way to identify the mould species is by laboratory testing.
  • Sometimes we make small changes in our homes, that may enhance the condition for mould growth. Such as not opening windows up often anymore, using a gas heater you haven’t before, using your dryer more often etc.

Our Service Offering

Expert help and advice is just a phone call away 093920000 or email