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Don't Ignore Mould in the Home

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By EnviroVent Nov 14, 2016

Damp and mould are caused by excess moisture. Moisture in buildings can be caused by leaking pipes, rising damp in basements or ground floors, or rain seeping in because of damage to the roof or around window frames. In a newly built home damp can occur if the water used when the house was built is still drying out. Additionally, If your house has poor insulation, this can encourage mould growth, including on the ceiling. The effect of cold air on the outside of walls and warm air on the inside can cause condensation. When warmer, more humid air meets the cold wall, condensation forms, contributing to mould problems.

Inhaling mould fragments or spores can inflame the airways, causing nasal congestion, wheezing, chest tightness, coughing and throat irritation. Prolonged exposure to high levels of indoor dampness can reduce lung function and cause chronic health problems such as asthma.

Occupants of damp or mouldy buildings are at increased risk of experiencing health problems such as respiratory symptoms, respiratory infections, allergic rhinitis and asthma. Some people are more sensitive to mould than others, and some groups are especially vulnerable.

Mould is a fungus that breaks down dead material. It grows in our homes because they offer the ideal conditions for it to grow – namely moisture, warm air, and materials to feed on, such as wood, carpet and dust. It will continue to develop until it’s cleaned and removed. However, dead spores can be just as harmful to our health, so it’s important that you take care when getting rid of it. 

Considering the volume of rain that the average UK home has to deal with each year it’s no wonder that occasionally some homes will suffer from damp and mould problems on their internal walls. All mould need to thrive is humidity. Due to their high levels of moisture, bathrooms and basements are the most likely rooms in a home to harbour mould or mildew, but mould can grow anyway - including your bedroom. When mould reproduces, it forms spores that travel through the air, enabling mould to spread throughout the area. 

Mildew is the name for the most common type of black mould on walls, characterised by spots that can then spread over larger areas if left untreated. To find out if you have mildew on your walls, apply some bleach onto the affected area with a cloth. If the dark colour fades after a few minutes, it's mildew.

The causes damp walls and mould on walls can include broken or breached damp proof courses, cracked or missing roof tiles, guttering problems, cracks in mortar and joints, problems with lead flashing, compromised or ineffective drains, and a number of other factors. 

Of course this doesn't attack the source of the mould and you need to investigate why you had a mould problem in the first place, otherwise it will just come back. The most common causes of mould and mildew are high humidity, condensation and water leaks (which are often hidden). Mould is a common household problem. It can be caused by poor ventilation, leaking pipes and moisture in the air, which causes condensation. 

When you combine on or more of these problems with poor ventilation, then internal walls will struggle to fully dry out, even if the original source of water ingress has been repaired, leading to mould problems. Damp and condensation can cause black mould on your internal walls and window frames. If you experience black mould the first thing to do is identify the source of the moisture.

How mould can affect your health 

Exposure to damp and mouldy environments may cause a variety of health effects, or none at all. Some people are sensitive to moulds. For these people, moulds can cause nasal stuffiness, throat irritation, coughing or wheezing, eye irritation, or, in some cases, skin irritation. People with mould allergies may have more severe reactions. Immune-compromised people and people with chronic lung illnesses, such as obstructive lung disease, may get serious infections in their lungs when they are exposed to mould. These people should stay away from areas that are likely to have mould, such as compost piles, cut grass, and wooded areas.

Mycotoxins can kill neurones in the brain, which directly affects our mental capacity and can alter our psychological makeup. Some of the neurological symptoms of the ingestion of mycotoxins include confusion, dizziness, a ‘foggy’ brain, hallucinations, seizures and trembling.

Other important symptoms to look out for, relating to respiratory, circulatory and other conditions, are difficulty breathing; bleeding gums; nose bleeds; cold and flu symptoms; vomiting blood; wounds that won’t heal; blurred vision; nausea; and jaundice. Infection from damp and mould is very serious so it is imperative that if you notice any of the above symptoms you seek medical attention. 

There is also evidence that mycotoxins are carcinogenic, which can lead to the growth of cancers.

What is the Difference Between Mould and Mildew?

Mildew usually turns black or brown over time whereas mould is usually fuzzy or slimy in appearance. It appears as irregularly shaped spots that can have different colours – blue, green, yellow, brown, grey, black, or white. Oftentimes, surfaces that are covered in mould begin to rot.

Everyday activities such as bathing, cleaning, cooking and even fish tanks and indoor plants can cause dampness in the air, leading to condensation and eventually mould. Even new built homes can be affected, if water was used in the building process it could still be drying out something which is made more difficult when coupled with those everyday household tasks. 

Rooms like kitchens and bathrooms are optimum environments for mould and mildew, as bathrooms are usually wet, damp moist and often dark. Mould can grow on a mixture of materials in a bathroom; tiles, walls, wood and blinds/curtains. You will often see mould growing on bathroom walls stretching from the floor of the wall up to the ceiling. Mould on the bedroom ceiling can be especially alarming, as it has such a detrimental affect on your respiratory function it's very important to remove the mould as soon as possible. It is very difficult to keep on top of mould in bathrooms as the biggest prevention is ventilation which is something that can be hard to create and maintain in bathrooms and kitchens. 

Insulation can be a reservoir for mould. Any insulation which you can see exposed in your home should be checked thoroughly for mould, especially if there was once a water problem in that particular room, or if there was once mould growth anywhere in the room. Even if the insulation looks clean at first glance make sure to thoroughly examine and inspect it.

If you do end up finding any mould in the insulation inside your home you will have to remove and replace the affected insulation as it will be impossible to completely clean all the mould out from it.

Mould can develop anywhere that is a moist or humid environment. Depending on the climate where you live, the quality of insulation in your home, and even the location of your bedroom within your home (basement-level bedrooms are most at risk), your bedroom may be more or less likely to develop mould.

Mould spores can also enter from outside your home, through an open window, or by traveling inside on your clothing or your pets.

Mould can also develop on your mattress, due to moisture from your sweat. Mattresses include soft, porous materials in their construction, such as cotton covers or foam comfort layers. Any of these can absorb moisture and cause your mattress to develop mould.

If you have found mould in one area of your bedroom, do a thorough sweep to ensure it’s not anywhere else in your home, as mould can spread easily. Did you know mould in the bedroom can actually affect your health? According to this article mould can affect your breathing, which in turn affects your sleep. 

Mould on Walls - A Health Hazard

Exposure to damp and mouldy environments may cause a variety of health effects, or none at all. For these people, moulds can cause nasal stuffiness, throat irritation, coughing or wheezing, eye irritation, or, in some cases, skin irritation. People with mould allergies may have more severe reactions.

Untreated, mould can cause allergies and respiratory problems, so it is important to ventilate your home well, keeping the moisture levels to a miminimum and looking out for potential problems.

Originally, toxic effects from mould were thought to be the result of exposure to the mycotoxins of some mould species, such as Stachybotrys chartarum. However, studies are suggesting that the so-called toxic effects are actually the result of chronic activation of the immune system, leading to chronic inflammation.

The World Health Organisation (WHO) reported that about 12% of new childhood asthma in Europe can be attributed to indoor mould exposure, which represents approximately 55 842 potentially avoidable Disability-Adjusted Life Years and 83 potentially avoidable deaths per year. So it's crucial that if you see any mould or mildew in your home treat it, kill it and cure it as quickly as possible. 


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The different types of mould most found in the home

There are many different varieties of mould that grow in an array of colours such as green, black, white, orange and blue. Some strains of mould are more harmful than others, and one particular strain of mould can grow in a variety of colours, depending on different circumstances. This makes it difficult to identify exactly which strain of mould is growing in your home, and therefore it is hard to determine whether or not you should be worried. Generally, it is best to get rid of all kinds of mould, before it spreads and either you or your family members become ill.

The most common types of mould that grow in the home are the black and green varieties.

Green mould

Green mould may be indicative of Cladosporium, Aspergillus or Penicillium mould. Not only does mould look unsightly, but it can eat away at your paint and damage it while releasing potentially hazardous spores into the air. Kill green mould on your wall to eliminate these cosmetic, structural and respiratory risks.

Green mould is very common in many houses in the UK and typically belongs to the aspergillus, cladosporium or penicillium families. Green mould can usually look 'fluffy' in appearance and can often be found growing on damp walls, inside cupboards and carpets and on damp fabrics and mattresses. 

Penicillium can cause sinus infections and inflammation of the lungs, whereas other strains of green mould can cause bronchitis and even pneumonia if left untreated.

White Mould

Likewise, white mould is often described as almost furry in look especially when found on damp wood. White mould is often found in cool, damp environments such as in basements, cellars and usually growing up a wall. White mould is often overlook as it can look like efflorescence.

Efflorescence is a crystalline deposit of salts often seen on the surface of concrete or brick work. It occurs when water leaves behind salt deposits you can differentiate the two by spraying water on the surface. If the residue doesn’t dissolve it is white mould. Efflorescence occurs when water moves through a masonry structure, bringing unbounded salts to the surface. When the water evaporates, a white, fluffy structure is left behind. This growth, while harmless, can appear very similar to white mould growth.

Blue Mould 

Blue mould is another common household mould that usually appears in wetter rooms like bathrooms and again usually on walls rising up to ceilings. Steam from showers and bathing is the optimum moist environment for mould to grow. 

Black Mould

All kinds of mould can be harmful to health, however, black mould is famously the one to watch out for. Most black moulds are fairly common and often come from the same strain as green mould. They can be treated with normal treatment methods, and are not to be a cause of great concern. Stachybotrys chartarum, also known as black mould or toxic black mould, is a variety of microfungus that produces its conidia in slime heads. It is sometimes found in soil and grain, but the mould is most often detected in cellulose-rich building materials from damp or water-damaged buildings.

There is, however, a particularly difficult type of black mould known as ‘toxic black mould’ or ‘stachybotrys’, which can have much more serious implications on your health.

How to identify black mould on walls

The growth of black mould growth on bathroom ceilings and walls is a sign of condensation, and in bathrooms there is generally plenty of that! The warm, air laden with moisture comes into contact with a cold surface and that cools the air so that it can no longer hold the moisture which then condenses on that surface. This is why condensation is typically found on windows and other colder areas.

Bathroom ceilings covered in mould have long been a source of concern for our users. There are three ways to stop the condensation and therefore the likelihood of mould growth:

  • Reduce the moisture that is created and circulates in the air.
  • Ventilate to remove the moist air before the moisture can condense and cause problems.
  • Heat and insulate your home so that there are less cold surfaces and the air is kept warm enough to hold the moisture so reducing the amount of condensation.

There is no avoiding the moist air in a bathroom so it is virtually impossible to reduce the moisture content in the air. Ventilation can be effective and an efficient extractor fan will help reduce condensation enormously and therefore the likelihood of mould growth. Other ventilation such as opening a window may not be practical especially in winter when it will make the bathroom very uncomfortable. Improving heating and insulation may be expensive and potentially unaffordable in the circumstances, but they are an option.

This means that condensation and black mould are most often found in bathrooms, particularly those that are poorly heated and ventilated and especially when insulation properties are poor making the ceiling a particularly cold surface. When this is the case and mould has started to grow it is very difficult to stop it.

Toxic black mould and less harmful black mould look very similar, which can make the degree of severity of your problem difficult to ascertain. Toxic black mould tends to be a greenish-black and is often slimy, however, it can also become dry and powdery over time.

It requires a high cellulose and low nitrogen compositional surface on which to grow, and also requires more moisture than other strains of mould. It is often found in and around particularly damp areas and is a particular problem in areas which have sprung leaks that are hidden from view, such as inside walls or in floors and ceilings. Deformed walls and peeling patches of paint are key things to look out for, as they are indicators of internal dampness.

If you discover an area of mould in your home that suspect may be toxic, the only way to properly identify it is to enlist a professional mould inspector, who will look at it using a microscope. 

Cleaning Mould from Walls

There is no one cure for mould due to the variety and level of severity the mould is and some require professional removal. For example if you have a problem with toxic mould, then you need to seek professional treatment in order to ensure that your home is a safe environment for you and your family. If you find a colony of toxic mould, it is very important that you do not disturb it. Touching or moving the mould can cause an enormous amount of harmful spores to be released in the air, to the detriment of you and the people you share your home with.

For other, more common strains of mould, there is a wide variety of mould treatments available that clean the mould, which are easy to use on your own.

First, you must thoroughly clean your walls before getting rid of the black mould located on it. To do this, you'll need to use warm water with a mild soap brand. Next, pour the mixture into a spray bottle and apply it to the walls containing the mould. Use a sponge or a scrub brush to clean the walls completely.

A simple solution for removing non-toxic mould from your home is to clean it using a non-toxic, mould cleaning solution. When the mould has been eradicated, it is important to dry the surface thoroughly, in order to prevent the mould from returning.

Another simple yet short-term solution is to kill the mould and nasty marks on your walls with bleach. If you do wish to try this tactic remember to wear thick clothes (you don't mind getting ruined), rubber gloves and a face guard as both the mould and bleach fumes can be dangerous to inhale. To clean mould off your walls, follow these steps -

  • Simply mix one part bleach to four parts water.
  • Using a damp cloth gently scrub until the mould is gone.
  • Once finished, dry the area well with a soft cloth.

Remember however, this is not a long term solution and you really need to tackle the cause of the mould to ensure it doesn't come back. If the mould is as a result of sewage or floodwater you should not remove this yourself as it can be harmful to your health. It is best to seek a professional as the area will need to be treated and disinfected. 

How to remove mould from exterior walls

Removing mould from an exterior wall is different to an interior as you are often dealing with exposed brickwork or plaster outside whilst inside most walls will be wallpapered or painted. 

Firstly, shoot down the wall with a pressure washer's fan spray. Use smooth, even strokes to cover the entirety of the wall, not just the area on which you notice mould growth. This forcefully removes most of the mould spores from your wall's paint and crevices. If you don't have a pressure washer, use a garden hose with a sprayer attachment to rinse the wall as best you can.

Next, create a mould-killing solution. Pour a gallon of warm water into a plastic bucket. Mix in 1/2 cup of household bleach and 1/4 cup of standard powdered laundry detergent. Stir thoroughly. Mix in 1/2 cup of trisodium phosphate, a cleaning agent available at many hardware stores.

Sponge the solution onto the green mould growth. If the mould growth is widespread, you may wish to use a garden sprayer, such as the type used to spray herbicides or liquid fertilisers. Allow the solution to soak on the wall for 15 minutes, during which time the bleach will sterilise the surface and kill the mould.

Scrub the wall with a sponge. While the mould may be dead, some staining and mould growth may still be visible. The trisodium phosphate and laundry detergent will help loosen any mould stains.

Rinse the wall by shooting it down with a water hose. Let the wall dry thoroughly, which may take 24 hours or more depending on your climate.

How to remove black mould in the bathroom 

There are various ways of identifying mould in your bathroom. Remember, mould forms from the inside out, so if you can see it, the issue may already be severe and will need fixing as soon as possible. Below are tell-tale signs of mould forming in your bathroom:

  • Smell: A constant damp smell, even when your bathroom looks completely dry and clean, is a sign of mould forming. This can be down a hidden leak in a pipe or a build-up of moisture.
  • Dark Appearance: If your wall or tiles look brown and muddy with a damp and slimy looking appearance, this could be black mould growing.
  • Damaged Walls: Crumbling plaster, off-coloured walls, blistered paint or cracked tiles, or warped walls may mean that moisture has got into the walls, causing mould to grow.
  • Unstable Floors: If your flooring feels soft and spongy - perhaps under tiling - you may have moisture underneath, result in mould forming.

Bathroom mould isn’t always obvious. Check out hidden areas, such as under sinks, access doors to shower and bath fixtures, around exhaust fans, even in crawl spaces and basements underneath bathrooms.

To remove mould from a bathroom -

  • Strip away and replace any caulking or sealant that has mould growth.
  • Clean your bathroom with mould-killing products, such as bleach, vinegar, or hydrogen peroxide. Just don't mix those products; mixing can cause toxic reactions.
  • Open windows and doors while cleaning to provide fresh air and help dry out the mould.

Removing mould in a wardrobe 

When dealing with bathroom mould, bleach products such as Domestos, are the best removal methods. However, when it comes to wardrobes, bleach may not be appropriate for a particular material, or for a delicate wood or finish. Even when diluted, bleach is a very strong substance, and it could eat away at the protective gloss on your wardrobe, create damage to the wood, or cause discolouration. For wooden surfaces and vulnerable materials, it’s always best to use as gentle a cleaning solution as possible. This is why preventing mould in wardrobes takes a little extra care.

Mould in wardrobes derives from two main factors: condensation and damp clothing. The first step in stopping mould is removing any mould that is already present in your wardrobe. An alternative to using bleach on wooden surfaces is to use white vinegar. Always test any product in a small area first before continuing.

  • Treat with a 50/50 mixture of vinegar and water. This will remove the very outer layer of the mould, removing any black residue. 
  • Dip a cloth into the solution and wipe over the affected surfaces. It may now look as if the mould has completely gone, but there may still be spores remaining deeper down. 
  • This should be treated with undiluted vinegar, and left to dry. 
  • The surfaces of your wardrobe can then be rinsed with cold water, and towel-dried. This should kill off all mould that’s already growing inside the wardrobe.

Now, you’ll want to employ some simple prevention tactics:

  • Move your wardrobe out a few centimetres from the wall to prevent condensation from seeping into the cupboards.
  • Never hang damp clothing in your wardrobe. Always ensure that it is completely dry before putting it away.
  • Don’t overfill your wardrobe. If clothes are tight up against each other, mould can grow from the fibres of one item to another, encouraging the spread of spores.

What causes black mould?

Many black moulds are toxigenic, meaning that they release toxins that can be irritating or even harmful for people who have preexisting conditions. Called mycotoxins, they're produced as mould spores eat, grow, and form colonies with other spores.

The majority of moulds found in the home are caused by excess moisture, usually this is due to high humidity levels in the property but it could also be caused by leaking pipes, rising damp, rain seeping in due to a damaged roof or window frame. In new build properties you may start to notice excess moisture and even mould due to the property not drying out yet. It is important to remove the mould problems in your home as soon as possible as left untreated it can soon become a health risks to those living in the property.

Toxic black mould

Stachybotrys, or toxic black mould, is harmful in the home because it produces mycotoxins. Mycotoxins are invisible to the human eye but can enter the human body through inhalation, ingestion and even through the eyes. These mycotoxins are very dangerous and can cause problems with the reproductive system, vision, skin, the circulatory and respiratory systems and can even have psychological and neurological effects.

Some mycotoxins cause immune system responses that vary considerably, depending on the individual. The duration of exposure, the frequency of exposure and the concentration of the insult (exposure) are elements in triggering immune system response.If you are experiencing worrying symptoms and cannot identify the cause, it is important to check your house for signs of black mould.

Mould mites

If your home has experienced damp you are quite likely to have, unfortunately suffered with mould mites. Mould mites are closely related to dust mites, like dust mites they can be difficult to see with the naked eye. Mould mites feed on mould and love damp conditions, if you are experiencing any issues with damp you are likely to fid an infestation of mites soon after. 

Although mould mites can't bite or cause grievous harm they can cause an allergic reaction or worsen some-one who is already susceptible to allergies and irritants. They multiple quickly so you need to act fast to remove them. Most importantly is to remove all mould from your home, depending on the severity you may need professional help. Then ensure your property has been properly deep cleaned and all traces of mould such as; soft furnishings or bedding has been removed. 

Once removed you need to ensure your home stays mould free, in order to keep the mites away. The best way to do this is to adequately ventilate your home at all times, you can also use anti-allergy bedding to protect mattresses, duvets and pillows from mould spores and mites.

Treating an allergic reaction to mould

There's no complete cure for allergic rhinitis caused by a mould allergy, however there are a number of medications can ease your symptoms. For example; 

  • Nasal corticosteroids. Nasal sprays help prevent and treat inflammation caused by a mould allergy. 
  • Antihistamines. These medications  help with itching, sneezing and runny nose, these can be taken as a tablet or nasal spray. 
  • Oral decongestants

How to treat toxic black mould

If you are experiencing symptoms due to toxic black mould, the only way to treat it is by removing either the mould or yourself from the environment. Over time, your symptoms should begin to disappear, however, some damage can be permanent, which is why it is important to monitor any changes in your home especially on the walls and ceilings. Then if you notice any changes, treat the mould as soon as possible.

Seven mould prevention tips

In addition to ventilation and heat retention products, it is also important to ensure that your home is well cared for in other ways, in order to prevent unnecessary moisture which causes mould and mildew to appear in the first place.

1) Check to see if your windows are allowing rain to seep in and if the sealant around them is damaged. Additionally check there is no damage to your roof as this could also allow rain to seep in and damage the interior of your property. 

2) Always make sure that you dry wet areas immediately. Wipe up spillages and make sure to dry floors and walls after you take a bath or shower. If possible, dry wet clothes outside or in a dryer rather than on radiators, as the moisture from your clothes travels straight into the air. Never leave wet clothes in the washing machine and replace water-damaged carpets and fabrics immediately.

3) There are a lot of products available to aid with mould prevention, such as mould sprays and mould prevention paint. If you are having building work completed in your home, it is possible to obtain mould-resistant drywall or gypsum board, which is designed to prevent moisture within the structure of your home.

4) A good way to monitor humidity in your home is through a moisture meter, which can be bought from most good DIY stores. Ideally, humidity should be between 30 and 60 percent.

5) Although indoor plants improve the air quality of your home, moist soil and leaves also provide the perfect breeding ground for mould. Make sure you clean and move your plants around regularly, in order to prevent a build-up of mould.

6) Leaks are commonly caused by broken gutters or drainpipes. Make sure to inspect the exterior of your house regularly, in order to prevent a simply cracked drainpipe from becoming a larger and more expensive problem.

7) Finally, it is important to let air circulate through your home. Keep internal doors open as much as possible and move the furniture away from walls. Open windows on dry days to let fresh air blow into your home, which will reduce moisture and therefore help to prevent mould.

The Best Way to Prevent Mould

Once you have treated your mould or mildew, it is important to make some changes to the way your room is ventilated, in order to prevent further outbreaks.

At EnviroVent, we have a range of products that can help to keep your home well-ventilated and mould free. For badly-ventilated kitchens and bathrooms, it is definitely worth installing an extractor fan, such as our Cyclone 7. It effectively tracks and detects water vapour in the atmosphere and comes with a 7-year guarantee, so you can relax in the knowledge that your home is a safe and spore-free environment.

We also have a range of condensation control units to suit your individual needs. Our whole house ventilation systems remove moisture and dampness from the air caused by cold in the winter, and will also work to cool rooms down in the summer, preventing water vapour caused by humidity. We have condensation control units specifically designed for loft spaces and flats and apartments, as well as more traditional houses.

If you want to improve the indoor air quality in your home, we recommend our single room heat recovery unit. Using state-of-the-art technology, it simultaneously retains heat within your home and provides fresh air from outside through internal tubes, meaning that you can feel the benefits of opening your windows without increasing your chances of condensation.

All of our products are energy efficient and make your home a more eco-friendly place by utilising the air up to 75% more than under ordinary circumstances.

Need help with condensation, mould or damp problems?

Arrange a FREE Home Survey now

One of our local experts will contact you to learn more about your problems, offer free expert advice and make recommendations for a permanent solution.

During the free survey we will:

  • Assess any condensation, damp or mould problems in your property
  • Take readings of the relative humidity levels
  • Identify any underlying problems and make recommendations for a permanent solution