Mould on internal walls (often called black spot mould) can be the result of moisture being drawn in through the walls of your property and results in your having to re-decorate on a regular basis. If the damp patch on the wall is more than half way up the wall (in a downstairs room), chances are your suffering from penetrating damp.
There are several causes of penetrating damp, some of which are easily cured. Check to see if you have blocked gutters or drain pipes which may be making rainwater run down the wall of your property.
Although faulty window surrounds, guttering, down-pipes and roofing all play a part, the single largest contributing factor to penetrating damp is poorly maintained or damaged property walls. Over time, cracks appear in pebbledash, the surface of bricks are blown, rendering crumbles and stonework flakes. These openings and the porosity of building materials allow water to ingress into the house by osmotic action and lead to penetrating damp.
A single house brick can soak up to a pint of water. Cement, render, pebbledash, Tyrolean and Spa Dash, fair no better a square yard of these materials can retain up to 8 pints of water! As this damp penetrates into the building it comes into contact with the wooden beams, floorboards, joists, window frames, skirting boards and plaster.
This is when the damage really starts, with wet rot, dry rot, growths of mould, blackspot and mildew.
Not only are there the financial costs of treating, repairing and replacing the affected areas, but there are also health issues to be concerned about.
A resin based wall coating may be the answer. If you already have render or pebbledash or some other coating on the outside of your property, you will need a specialist application. Not only this is totally impenetrable to water, but more importantly, it is micro-porous. This means that although water cant get in, water vapour trapped inside your home can escape leaving the structure dry, safe and sound.
Good advice here. Damp walls can really affect your health if not dealt with.
Rated: 5/5 (22nd July 2009)