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The Menace of Mould in Housing: Causes, Health Risks, and Solutions

Mould and damp are an unfortunate reality in many homes and rental properties across the UK, a state of affairs resulting from issues ranging from dampness caused by the lack of proper insulation in window frames or heaters, often evident on window sills, to problems with the roof. These issues navigate us to a complex situation in which the structure of the accommodation itself, from the plaster on the walls to the roof overhead, can sometimes become compromised. Needless to say, the signs are not always visible initially. The situation often escalates due to impaired airflow, leading to stagnant damp air in enclosed spaces. The numbers tell a grim story with recent estimates suggesting up to 1 in 5 households are affected by some level of mould growth.

What Causes Mould Growth Indoors?

Left unchecked, a small patch of mould can rapidly take over entire rooms or properties in a multitude of ways, hence, owners and renters need a guide to handle this issue effectively. This not only destroys the aesthetics of a home but also puts occupants’ belongings, particularly those in a tenancy agreement, at risk of developing respiratory conditions or allergic reactions. Depending on the circumstances, the health implications can be as grave as death.

To understand what causes mould to thrive inside houses, and what are renters’ and homeowners’ responsibilities when it comes to inspection, reporting and remediation, this article explores the science behind mould in housing and provides practical advice and services for prevention and removal. In this course, anyone, whether a tenant living in shared baths or a homeowner, can gain knowledge and experience in handling such unfortunate situations.

Mould is a type of fungus that produces a number of microscopic spores to reproduce. A good surveyor would note it thrives in damp, humid environments with little air circulation. This makes areas such as basements, attics, and bathrooms prime targets, along with window frames, especially those with window sills, that may suffer from mould problems due to poor insulation or heating systems. However, mould can colonize any part of a building with the right conditions:

Moisture – From leaky roofs and pipes and faulty window structures to flood damage, excess moisture enables mould growth. High indoor humidity also plays a role.

Poor ventilation – Lack of adequate airflow prevents evaporation, creating an artificially damp environment that allows surfaces to remain damp for longer.

Health Risks From Indoor Mould

Porosity – Porous materials like drywall, carpet and wood provide the nutrients mould can feed on.

Warm temperatures – Most mould grows best between 40-100°F.

To combat these things, controlling relative humidity below 50% inhibits most mould types [2]. Proper ventilation, for example through window opening, is also critical – this can be achieved by installing bathroom/kitchen fans and using dehumidifiers or air conditioning.

  • From a health perspective, expert advice, inspection and testing services are vital to confirm the health risks of mould spores and particles which can irritate lungs and trigger allergic responses or asthma attacks.
  • Coughing/wheezing
  • Sore throat
  • Runny nose
  • Eye irritation
  • Rashes
  • Headaches

Landlord Responsibilities for Mould in Rented Property

Those with compromised immune systems – such as infants, elderly and chronically ill people – face heightened reactions. If such an issue arises, a free inspection by a professional mould removal expert could prove to be a vital step in confirming the presence of mould and initiating the process of removal. Letting agents, landlords and councils have clear legal duties regarding the condition of their properties, including addressing condensation problems. They are responsible for maintaining the structure of the property, including the integrity of its windows and roof tiles. If tenants discover an issue, such as mould growth around window frames, problematic installation of bricks, or issues with roof tiles, they should report this for immediate attention. Specifically, reporting it to the local council environmental health teams is the right action as they have the capacity to provide efficient investigation and results.

Tenants have certain obligations too, namely in maintaining the cleanliness of the property, including taking adequate care of the guttering to prevent damp and promptly reporting any issues of damp or mould they might discover during their tenancy. Ensuring the bricks of the exterior structure are in good condition is also crucial in preventing mould propagation.

Renter’s Rights and Responsibilities

Tenants have certain obligations too, namely in maintaining the cleanliness of the property, including taking adequate care of the guttering to prevent damp and promptly reporting any issues of damp, mould, or condensation problems they might discover during their tenancy. Ensuring the bricks and roof tiles of the exterior structure are in good condition is also crucial in preventing mould propagation.

  • For homeowners and tenants living in flats, who are struggling with persistent mould, the problem may often lie with initial construction flaws, such as defective guttering, incorrect installation of bricks, or poorly fitted roof tiles. This issue raises questions of liability, including who is responsible for mould in a new house, and provides guidance to human habitation in such areas where the health of inhabitants might be at harm. Overlooking such issues at the construction stage can inevitably lead to detrimental results in the future.
  • In England and Wales, Section 38 of the Building Act 1984 requires all works to comply with building regulations. If initial structure conditions, problems with the bricks’ installation, window frames, roof tiles or guttering, lead to mould problems, owners can pursue civil claims against builders, developers, and councils, perhaps even involving their legal team to understand better the effects of such defects. In addition to that, you generally have 6 years from completion to file court action.
  • Promptly report any damp, mould or condensation problems to the landlord/agent
  • Provide access for inspection/repairs
  • Take reasonable steps to prevent moisture build-up through proper heating, ventilation and cleaning
  • Take reasonable steps to prevent moisture build-up through proper heating, ventilation and cleaning

Specific defects like leaking roofs, cracked tanking, or inadequate insulation in one’s resident should be addressed urgently. Adverse results from overlooking such issues – like the compromised installation of bricks – must be remedied under warranty. It is only through detailed examination and decisive action that such unwelcome guests as mould and dampness can be evicted from your home. Most builders provide cover lasting 10 years for structural elements pertaining to such work. For new properties, the government, as well as housing associations, encourages owners to thoroughly check for faults in the guttering and document any damp or mould issues from the outset. Providing this essential information at an early stage, in well-documented cases, is paramount as it prevents enormous health problems down the line

With vigilant exactness, households can keep problems with mould in housing at bay and protect health. However, if mould growth seems out of control, professional help may be needed.

In the world of regulations, there are no federal limits on mould spores indoors. Preventing such a problem may have to begin with changes from the initial installation of materials, including bricks, which can impact the overall health of a property’s structure and its occupants as a consequence of preventing or promoting mould.But the informative body known as the Institute of Medicine suggests keeping levels below 50 spores/cubic metre to prevent allergic reactions, particularly in homes meeting the decent homes standard. Those with asthma or compromised immunity may react at much lower concentrations, including mould appearing on ceilings. Any visible sign of mould warrants inspection and removal, not just for the well-being of individuals, but for the wider health of communities.

Practical Tips to Limit Mould Growth

  • Open windows regularly to circulate air and reduce condensation build-up in key areas such as ceilings. This simple action can significantly reduce the proliferation of bacteria associated with mould growth.
  • Use extractor fans when cooking and showering. This prevents moisture buildup, which is essentially the mortar that holds together the conditions for bacterial growth and the subsequent development of mould, particularly in communities with many homes close together.
  • Run dehumidifiers in damp rooms, especially in homes where the quality of infrastructure like ceilings and home mortar, might make them more susceptible to mould. This can help cut off the symptoms experienced from exposure to mould, reducing the overall bacterial load in the space.
  • So-called ‘toxic black mould’ refers to the species Stachybotrys chartarum. At very high levels, which can go undetected in ceilings or other out-of-sight areas due to mortar’s limitations, it can produce harmful mycotoxins that can pose risks to individuals and communities. Stachybotrys is relatively rare indoors, but any visible sign of mould should prompt immediate action to maintain a decent homes standard.
  • Maintain consistent indoor temperatures above 15°C, a step towards a decent home and reducing bacteria borne mould growth. This would act as a proactive process in maintaining a healthy mixture of your indoor air and mortar, and to help reduce mould-related symptoms as well.
  • Avoid blocking radiators with furniture, an excellent habit for adults in all communities to prevent mortar dampening and mould accumulation, particularly on ceilings.
  • Open internal doors to circulate warm air throughout the home, an aspect of the decent homes standard often overlooked. This circulation can help obstruct the conditions that bacteria love, reducing mould symptoms.
  • Dry wet ceilings and other surfaces like tiles and windows to discourage mould as part of the wider decent homes standard. This act not only maintains the integrity of your home’s mortar but also keeps bacterial growth at bay, subsequently reducing mould symptoms.
  • Prevent condensation build-up on ceilings by wiping down cold glass surfaces. This acts as a prevention against inviting bacteria to grow and preventing any health symptoms associated with mould.
  • Clean bathrooms/kitchens with anti-mould products to ensure all ingredients for mould growth are removed. This effective approach controls bacterial growth, preserves the quality of your home’s mortar and prevents mould-induced symptoms.
  • Cover pots when boiling food to reduce steam, an important ingredient in mould growth, particularly on ceilings. This basic practice safeguards mortar and helps keep bacterial counts under control thereby preventing mould symptoms.
  • Dry laundry outdoors when possible to minimize moisture buildup in homes, which can lead to the development of mould, particularly on ceilings. This is an additional way to combat bacteria from thriving and causing possible health symptoms.
  • Check pipework and seals for any leakage as part of a holistic approach to maintaining a decent homes standard in all communities. Any water leakage can degrade mortar and create a conducive environment for bacteria to multiply, eventually leading to mould growth and associated symptoms.

Getting Help From Home Disrepair Experts

Inspection – Trained specialists conduct thorough visual examinations of various spaces, including any available inch of the ceilings, to identify moisture issues and map out mold spread. This is done in an incessant effort to maintain the decent homes standard. To identify less visible problems within walls or building cavities accurately, which are often difficult due to the limited amount of visible area, individuals skilled in the field utilize specialized tools such as moisture meters, borescope cameras, and air quality tests.

Testing – Surface and air samples are carefully analyzed to determine mold types present, spore counts, and potential toxicity. This crucial information, gathered from a predetermined amount of gathered samples, informs appropriate remediation methods tailored to the specific needs of individuals living or working in the affected space.

Remediation – From minor leaks to major flood damage, individual disrepair experts handle the necessary repairs to rectify moisture sources. They employ specialized equipment to kill and safely remove mold from porous materials it has colonized, irrespective of the amount of damage.


Tenants can make disrepair claims against landlords if issues like leaky pipes, cracked foundations, faulty ventilation etc. lead to mold growth that impacts health. This is especially significant for individuals sensitive to mold exposure, who require a mold-free space for their wellbeing.

To support a claim, tenants as individuals need to provide evidence clearly linking the disrepair to mold development and subsequent illness/injury. This involves demonstrating the amount of fungal growth and how it has proliferated in their living space.

Proper containment procedures are meticulously implemented to prevent spore spread during works. Post-project clearance testing then confirms mold eradication and air quality safety, ensuring conditions are safe for individuals to re-enter decontaminated spaces.

For new build homes with construction defects enabling mould, disrepair teams can provide expert testimony regarding negligence. All aspects of inspection, testing and reporting help support legal claims against developers or builders, particularly when individual residents lodge a complaint.

By leveraging the technical skills of home disrepair services, both tenants and owners, as individuals, can tackle mold issues. The expertise of these individuals traces root causes, documents extent of spread, mitigates health risks, and prevents recurrence, thus paving the way for a swift resolution of any complaint brought forward.

Claims fall under personal injury law and can seek damages for individual medical costs, lost income, decreased quality of life etc. Photographic evidence, speaking volumes about individual situations, helps prove negligence.

For the purpose of backing legal claims, disrepair experts like individual surveyors can step in and provide detailed inspection reports. Their professional testimony shed light on issues, mold spread and required repairs.


How much mould is dangerous?

Left unchecked, mould infestations can render properties uninhabitable and severely impact health. If it gets to the point of eviction due to mould, the problems have certainly heightened and so could the bills related to the situation. All occupants have a shared duty to control moisture levels. But landlords and housing associations bear particular responsibility for properly constructing, maintaining and repairing housing. The importance of addressing something as seemingly insignificant as cracks in the brickwork cannot be overstated as they can allow moisture to infiltrate the structure. By following best practices, the growth of this menacing issue can be arrested.

Can I break my lease due to mould issues?

Mold growth dramatically slows below temperatures of 40°F. Brief exposure to extreme heat above 140°F can destroy mold but does not penetrate porous materials to reach root structures and spores. Sustained heat treatment by professional remediators using temperatures above 120°F for hours is needed to fully kill mold, which could ultimately save on potential health-related bills and maintenance costs. This further emphasises the importance of a person’s role in maintaining safety within the property.

Is black mould more toxic than other varieties?

No, mold, including those growing in hidden patches on your carpets or creeping along the exterior, cannot and will not disappear without proper remediation. Since this type of fungi continually produces spores as part of its life cycle, infestations will keep worsening, causing concern especially with respect to potential infections and subsequent medical bills, if moisture sources are not eliminated. Trying to simply remove surface mould without addressing cracks or other defects allowing water ingress, or fixing the underlying water problems, a requirement for effectual control, will also cause new growth.

Should I paint over mould?

Mold does not stop growing on its own as long as moisture and organic matter are present, on the ground or within buildings. Even if visible mold is removed, colonies can continue spreading out of sight in building cavities, potentially causing structural damage and increasing repair bills.Over time, unchecked mold can consume drywall, wood and other materials, leading to extensive damage. Regular inspections including landlord access and moisture control, possibly with the use of a dehumidifier, are required to prevent exponential growth. It’s also necessary to promptly address the first sign of such a complaint made by the occupants.

Can I claim compensation for health issues from landlord’s mouldy property?

Certain natural products have anti-fungal properties that can help prevent mold growth when used properly. These include white vinegar, hydrogen peroxide, essential tea tree oils, grapefruit seed extract and boric acid powder. However, these agents alone cannot substitute for fixing moisture issues, cracks, or professional mold remediation. Their effectiveness also largely depends on the person administering the treatment, making it more crucial to pay attention to any complaints about potential mold issues.

Does renter’s insurance cover mould damage to possessions?

To date no scientific evidence conclusively links indoor mold exposure to cancer or brain injuries. Certain molds like Stachybotrys release toxins that can damage cells over time. But extensive research, taking into account factors such as allergies, exposure time, and any complaint made about health issues, would be needed to directly correlate mycotoxins with tumor formation or neurological decline. Those with mold sensitivities do face higher risks for respiratory illness.