Mould Prevention, Mould Treatment, Mould Removal
We specialise in the eradication and prevention of Condensation Mould and & Mould Growth
The most common cause of dampness in buildings is condensation, which often leads to an attack of mould growth. The presence of moisture/humidity in the air can condense on walls, ceilings and other cold surfaces, leading to Black spot mould growth. Living conditions of a large proportion of the population are adversely affected by condensation. Its occurrence together with the subsequent mould growth has been the largest single complaint received by local authorities during the past twenty years.
The problem of condensation, particularly in houses, usually results from a combination of relatively simple, conditions, and is directly related to lifestyle and standards/methods of heating, ventilation and insulation of buildings. Condensation on walls and ceilings provides an ideal damp environment for mould to grow.
What is Condensation?
Air contains water vapour in varying quantities depending on its temperature - warm air holding more moisture than cold air. Air is saturated when it cannot contain any more water vapour at it's existing temperature whih is a relative humidity (RH) of 100%. If the temperature of the air falls when it is at saturation point - perhaps by coming into contact with a cooler surface, it cannot hold the moisture any more - this lower temperature surface brings the moist air below what is known as the dew point. Any fall in temperature causes the moisture to be forced to condense out as liquid water. The amount of water vapour condensing out will be the equivalent to the amount of vapour excess of 100% RH in the air at its new temperature. Therefore, when warm air comes into contact with either colder air or a cold surface the warm air is cooled, to a level at which it can no longer contain all the water vapour and some of it is releaseded as condensation or liquid water, this can often be seen on windows for example when warm moist internal air is reduced in temperature by the colder glass of the window.
Condensation can also form within voids or gaps in walls, chimneys or floors etc. This is known as Interstitial Condensation. This is rather more complex than surface condensation and the resulting hidden high moisture content can go unnoticed for long periods until serious structural damage can develop such as wet or dry rot.This interstitial condensation moisture can also affect any insulation (such as cavity wall insulation)where it occurs.
Conditions for Condensation
Condensation in domestic homes is mainly a winter problem particularly where warm moist air is generated in living areas and then affected by colder parts of the building.
Water vapour can be produced in quite large quantities through lifestyle and common tasks. It can also rise from damp ground beneath properties and in some cases penetrate timber floors and pass freely up the cavities of brick walls into roof space. The severity and effects of condensation will then depend on the type and style of construction of the building.
The build up of roofs can increase the occurrence of condensation, especially in the winter. In a flat or decked roof construction the waterproof roof membrane is also a vapour barrier. The water vapour is then prevented from escaping causing condensation to occur within the voids and to condense under the roof sheeting or sarking felt and drip from it.
Condensation can also occur in cavity walls where moist air in the construction and external cold air are able to circulate in a confined space. The temperature of the moist air is lowered, reaching the dew point and moisture is released to the coldest nearby surface.
Condensation will also occur under suspended floors where the temperature of humid air in the floor space is lowered by cold air moving in through ventilators and water is then condensed on the underside of floor. This can often induce timber decay to the wooden floor.
Mould growth can establish on any damp surface within the home such as plaster, wallpaper and timber. Mould can appear in many forms and various colours - greens, yellows, pinks, black, grey or white), often has an odour (musty and damp), and has health and hygiene considerations. Moulds are simple fungi where spores are produced and realeased to find a moisture source in an area with suitable temperature and food requirements.
Different materials have different susceptibility to mould growth. It has been demonstrated that mould will develop on cheese and leather at 76% RH. It will not develop on wood below 85% RH or on cotton or glass below 96% RH. The longer surfaces are under conditions of high moisture or local high humidity the greater the probability of mould growth developing.
There are approximately one hundred species of fungi detected and recorded in domestic homes. Species commonly encountered are Penicillium, Cladosporium, Rhizopus, Mucor. Fungi specifically encountered on paint and plaster were for example Cladosporium cladosporioides, Aspergillus niger, Penicillium purpurogenum and Mucor plumbeus.
The appearance of mould growth in buildings often suggests poor standards of property maintenance and/or domestic activities encouraging condensation. Prolonged exposure to mould growth will cause disintegration and disruption of certain painted surfaces. Paper and certain fibre building fabrics may also be softened and deteriorate as some mould species are capable of digesting cellulose.
The Cost of Unchecked Condensation
A paper in the British Medical Journal, Vol. 298, June 1989, stressed the higher incidence of ill health in damp buildings with accompanying mould growth and it is now accepted that air pollution is a major reason for the huge increase in asthma sufferers of whom children are often the most vulnerable.
The direct cost of a condensation and mould growth problem where only one room has to have mould cleaning or redecorating is at least £250 per year, and in many cases can be more than this, If for example more than one room is involved. Sometimes window frames need to be repainted and repaired, or even replaced.The occupants’ clothes and other belongings may go mouldy and need to be replaced. we have been told of some cases where the occupant has taken their Landlord to the Courts and compensation payments of several thousand pounds have resulted.
In addition these direct costs, there is a substantial ‘hidden’ cost which relates to administration. In the case of Local Authorities and Housing Associations for instance, a Surveyors time is consumed in repeatedly being subjected to the Tenants complaints. In some instances Surveyors productivity is impaired by this disruption and aggravation.
Condensation and black mould are a serious hazard to health. The Environmental Protection Act 1990 puts the onus on all landlords to ensure that their properties are designed and maintained to a standard that prevents conditions arising which can lead to any defect causing damage to the health or personal property of the tenant. Condensation and black mould fall very much into this category.
Under the Act, Landlords also have a Duty of Care to their tenants, to ensure that the premises are constructed and maintained free from defects which might cause personal injury or damage to the property of the occupant.
It is a proven medical fact that black mould can cause respiratory problems and condensation and dampness can aggravate asthma suffering as well as causing mental distress. It is therefore vital that black mould is cleaned off and condensation problems eradicated as quickly as possible.
Mould growth and condensation can be prevented by a combination of:
Reduction of humidity
Or you can of course eliminate the source of the dampness.
Eliminate harmful allergens and mould growths in your home. Ring our specialist team, for reliable mould and mildew prevention, treatment and removal.