Rising Damp - Condensation and Black Mould in Buildings:
Condensation occurs when moisture in the air which can come from a variety of sources condenses onto a cold surface. Typically the surfaces of windows and walls (especially if the walls are painted with a silk finish) will drip with moisture, which will generally collect in corners, window reveals and on the tops of skirting boards.
Sources of moisture in the air.
Cooking & Bathing.
Condensation most commonly occurs in buildings which do not have adequate ventilation. Typically those built after 1920, when cavity walls and concrete floors were introduced and of late double glazing & cavity wall insulation. The lack of ventilation causes dead air spaces to occur in the corners of buildings. Within these spaces moulds and mildew can start to grow on the surfaces of wallpaper and paint.
Images of Black Mould caused by condensation:
The images opposite show a property built after 1920, which is showing signs of mould growth caused by condensation. The growth is following the dead air space also the paint and plaster are not blistering. Which will eventually happen with rising or laterally penetrating damp.
Look at these images; of mould growth caused by condensation. .
Why condensation causes Black Mould to grow:
Airborne mould spores present in both outdoor and indoor air land in areas where there is reduced air circulation. They require very small amounts of water (provided by the condensation) and nutrients to start reproducing, forming the characteristic fusty blackness that can be found in many places. But typically in areas where ventilation is reduced and moisture can collect, such as: Corners of rooms, window reveals, bathroom & kitchen ceilings and in between tiles.
Black Mould (Stachybotrys chartarum) & Health Risks:
I have seen a lot of articles on the internet, referring to Black Mould as toxic I feel a little scare mongering to sell products is the cause of this; However here is a link on the subject. http://www.cdc.gov/mold/stachy.htm.
How to reduce Condensation in your property.
To reduce condensation you simply increase ventilation in your property. Typical methods include, opening or installing vents, opening windows & doors etc. However the latter can be impractical; especially in cold weather. A simple cost effective solution is to fit an extraction unit supplied by: http://dryhomecondensation.co.uk/
How to eliminate Black Mould.If your mould is caused by condensation it can be removed by spraying the effected area with either, vinegar, salt in solution, disinfectants or bleach, or a mixture of the aforementioned. However it will return. After cleaning therefore it is advised to mix an additive with paint that increases the surface area of the paint molecule, which prevents mould spores from settling within any painted area(s).
Mould Growth Consultants, sell kits that contain both cleaners and paint additives.
Is your Black Mould problem caused by rising damp.
The images opposite show a Victorian house in Waldegrave Road, Teddington, Middlesex, exhibiting typical symptoms of rising damp. Paint peeling and blown plaster above the skirting boards. The black mould is following the path of the rising damp and gets worse behind the washing machine. Where there is reduced air flow.
Rising Damp & Black Mould Growth:
If you have black mould growth as seen opposite in poor Jo's kitchen you can see that the mould is following the areas affected by rising damp. Please Note: It has been documented that the presence of salts, which are associated with rising damp, kill black mould, implying that if black mould growth is present your growth is caused by condensation. However this is not always the case as can clearly be seen in poor Jo's kitchen. So do not think that just because you have black mould growth, that you do not have rising damp.
Links about Rising Damp.
Rising damp is distinctive View "Googles" image archive of properties requiring damp proofing. Note that in most images the paint or wallpaper are peeling. The link will open in a new window.