DAMP PROOFING Does my property have a damp problem? At least 15% of all British homes show damage due to dampness. Visible symptoms are serious enough, but the ongoing underlying damage is the most worrying with entire structures being affected. Ask yourself the following questions: Do I have...  Wallpaper or paint coming away from the wall.  Discolouring of the plaster i.e. darker patches.  Mold or condensation building up in areas. The main causes of such problems are Rising Damp, Penetrating Damp and Condensation and can be rectified by quick and effective treatment. Rising Damp (Salt Damp) Rising damp (or Salt damp, as it is known in many parts of the world) is not the most common form of dampness encountered in buildings; this is left to condensation. However, a high proportion of older buildings are affected by rising damp to some degree or another. Rising damp in buildings may be defined as the vertical flow of water up through a permeable wall structure, the water being derived from ground water. The water rises through the pores (capillaries) in the masonry by a process loosely termed "capilliarity." In other words the masonry acts like a wick. Treatment of rising damp (known as "damp-proofing" or "dampcoursing") typically involves the installation of a chemical DPC using specialist injection equipment, followed by replastering using a salt retardant additive such as Renderguard Gold. Important Note: Rising Damp along with all damp problems is a health risk. We recommend that a survey is carried out immediately if any damp problem is suspected.   Rain Penetration into Masonry (Penetrating Damp) Normally caused by the elements, with rain or snow reaching the walls or ceiling, penetrating the brickwork. It also is evident around windows where poor sealing or faulty windows have been installed. Rain penetration into masonry (penetrating damp) can occur in buildings of all ages. At its most obvious, it penetrates right through the wall and is visible as a damp patch on the internal wall. However, rainwater penetration can be damaging to a property, even if it does not penetrate all the way through a wall. For example, moss growth, increased heat loss, and frost damage can be caused by rain penetration into masonry. Siloxane-based Water-repellents We use Safeguard's Raindance and Raincheck Plus products, they are designed to eliminate problems arising from rainwater penetration into masonry. They impart water-repellency to masonry without affecting the finish of the substrate (though some slight darkening may occur). These types of water-repellents work by lining the pores in the masonry. This allows the wall to "breathe," but means that they will only waterproof cracks of up to 0.3mm. Their efficacy will also be limited in very exposed locations with a high incidence of wind-driven rain. In such circumstances, the use of DryBase Plaster Membrane should be considered. DryBase Plaster Membrane Where a rendered finish is required, DryBase Plaster Membrane can be used to treat penetrating damp. The membrane can be fixed to the affected wall using the special DryBase Plaster Plugs. The mesh on the membrane can then be rendered directly on to. Using DryBase Plaster Membrane in this way has the advantage of being able to resist even wind-driven rain in exposed areas. The "air gap" created by the studs allows the wall to breathe. Important Note: Penetrating Damp along with all damp problems is a health risk. We recommend that a survey is carried out immediately if any damp problem is suspected. BACK TO TOP Condensation Condensation is by far the most common cause of dampness in buildings, probably accounting for the majority of damp problems reported. It affects both old and new buildings. Condensation is directly associated with mould growth. It is this that the occupier sees first, and it gives an indication of the potential scale of the problem. The mould is usually found on decorative surfaces, especially wallpapers, where it can cause severe and permanent spoiling. In many cases, the mould and its spores ('seeds') give rise to complaints about health, and cause the "musty" odour frequently associated with a damp house. The obvious places for condensation to occur are on cold walls and floors, but it can also occur in roof spaces and in sub-floor areas where there is a timber suspended floor; in the latter case, it can lead to rot developing in floor timbers. The Cause It is a fact that warm air can hold more water as vapour than cool air. Condensation is caused when moisture-laden air comes into contact with a cold surface - the air is cooled to the point where it can no longer hold its burden of water vapour. At this point, (Dewpoint), water begins to drop out of the air, and is seen as condensation on surfaces. On impervious surfaces such as glass and gloss paint, beads or a film of water collect. On permeable surfaces such as wallpaper and porous plaster, the condensing water is absorbed into the material. Therefore, the problem is not always initially obvious. Recognising Condensation is very much a seasonal problem, occurring during the colder months - October to April. During the summer, the problem is seen to go away. During the winter, ventilation of the house is usually low (due to windows and doors being closed, draught-proofing takes place). This allows build up of water vapour in the house, which, in some cases is sufficient to cause condensation. This condensation becomes apparent from the following symptoms:  Water droplets form on cold, impervious surfaces such as glass and paint.  Slightly damp wallpaper (often not noticed).  Development of moulds, usually black mould. In some cases, condensation may be long term, but intermittent, forming only at certain times of the day or night. In these cases, the only sign of condensation may be mould growth, as the moisture may have evaporated by the time moisture measurements are taken. The problem can occur well away from the site of most water vapour production. E.g. water vapour produced in the kitchen may diffuse through the house into a cold bedroom where it will condense on cold walls. Procure's Solution We can Improve ventilation by installing a Humidistat fan (specifically designed to remove moisture-laden air from kitchens and bathrooms), installing air vents, and extractor fans (a humidistat controlled unit can be used). If condensation is widespread we would install a a 'positive pressure system.' This consists of a slow speed fan set into the ceiling. It draws air into the roof space from the outside through the eaves, and gently pushes it into the property. This causes a slight internal positive pressure, continually pushing out any moisture-laden air. We can advise on: Removal of excess water sources, Insulation of Cold Surfaces, Installation of dehumidifiers and the prevention of possible Water Penetration with products like Safeguard Raindance. Important Note: Condensation along with all damp problems is a health risk. We recommend that a survey is carried out immediately if any damp problem is suspected. BACK TO TOP Copyright © Procure solutions 2003-2004. All rights reserved.