Black mould growth is generally not very nice, it is unpleasant to have it in your home, it is embarrassing to have friends and relatives see mould growing across your walls and ceilings and it will affect your health.
Many people think that it is caused through dampness. However, there are 14 different types of dampness according to the Building Research Establishment ranging through from rising damp, penetrating damp, bursts, leaks, floods, spillage, seepage, built in water, etc.
However, 80-85% of mould problems are attributed to one specific type of dampness – condensation – which is man made dampness. Only 15-20% of mould problems arise from true damp.
Condensation is most prevalent at certain times of the year although with the right conditions, can occur at any time of the year. Homes are most susceptible during the renown ‘Condensation Season’ – October through until April when it is a common sight to see condensation on windows, usually in the mornings in kitchens and bathrooms.
The air within your home contains water vapour – the amount depends on the temperature in your home. The warmer it is the more moisture that can be held, however, when moist air comes into contact with either colder air or a cold surface, it is unable to retain the same amount of moisture and the water is released to form condensation
The average family can produce up to 15 litres of water vapour in a day through normal activities of washing, bathing, cooking, clothes drying and breathing. That’s an awful lot of condensation and it has to go somewhere.
Older properties, particularly solid wall – solid brick, solid stone, solid concrete are much more prone to condensation and mould problems because the walls are much colder than modern properties with cavity walls and good insulation.
Fifty years ago most houses had high natural ventilation with sash windows and open fireplaces and the level of insulation was low. In recent times natural ventilation has been greatly reduced by the introduction of double glazing, draught excluders, fitted carpets the removal of open fireplaces and the introduction of central heating. Homes have now become sealed boxes and created the perfect condition for condensation and mould to occur.
The effectiveness of MGC products has been proven from over four and a half decades of successful application in social and private sector housing and also shown by tests carried out by the BRE, PRA and several other independent laboratories.
Even in warm, well ventilated houses condensation will occur in some form in the colder winter months. However, in poorly heated or inadequately ventilated dwellings, condensation can be serious and persistent and will lead to extensive mould contamination.
Homes which have insufficient insulation on the walls and loft space or properties which are of solid wall construction i.e. solid brick, stone or concrete are particularly susceptible to condensation. Certain types of construction and construction faults such as cold bridging exacerbate mould problems.
The incidence of condensation problems have increased tenfold in the past decade, a very high proportion are due to improvements that have been made to old homes or the style of construction for new build properties. Fifty years ago homes had natural ventilation with sash windows and open fires.
In the 21st century open fires are virtually unheard of, unless you live in the country and traditional sash windows have been replaced with varieties made from modern materials which has made homes virtually draught free. Furthermore, there has been great emphasis on insulating properties and the astronomical cost of heating ensures that nobody opens any windows for fear of losing their expensive heat.
That type of environment alone is unhealthy, however, when black mould takes hold even in small concentrations, it is a serious health risk which can result in asthma, bronchial complaints and other upper respiratory diseases.
It is estimated that a mould affected dwelling may contain between 3-7000 spores per cubic metre/1000 litres. There are several thousand species of mould that may occur in domestic dwellings, however, the most common are usually coloured black, green or white and are known as Aspergillus Niger, Penicillium spp and Cladosporium spp respectively.
Environmental Health Professional Practice. Mould Fungal Spores 1985 refers. The Royal Institute of Public Health and Hygiene 1993. Dampness, Mould Growth and Children’s Health. The British Medical Journal report Damp Housing Mould Growth and Symptomatic Health State 1989 confirms that active spores, even in small concentrations, are detrimental to the well being of adults and children. Mould also attacks foodstuffs resulting in dangerous toxins which in turn can give rise to food poisoning.
Mould is classified as a statutory nuisance under Section 82 of the Environmental Protection Act 1990. Under the Health and Housing Safety Rating Scheme 2006 (HHSRS) issued by DCLG, mould is a Category 1 hazard.