Many building suffer with condensation problems particilary if they are not well vented. Ventilation helps control condensation but the more ventilation the more the potential for expensive heat energy is lost if the building is heated. One the one hand we don't want condensation and on the other hand he don't want expensive heat energy lost the form of warm air leaving the building either. So we have a problem but there is a solution, the creation of a 'warm roof' solution that will minmise ventilation requirements.

Condensation left unchecked can over time lead to serious damage to a building; structural timbers will rot, mould will grow threatening the buildings air quality, metal materials and steel will suffer corrosion damage, masonry, concrete, and plaster will not bear up to being water saturated with freezing temperatures without suffering considerable damage. Condensation is a problem but a modern solution exists that can be fitted new or retro fitted to virtually all buildings where condensation is a problem and a high risk.

In buildings that otherwise do not have to be heated condensation is often a major issue. Condensation occurs when relatively warm and moist air meets a colder surface to the point that the average energy value of the air drops to a critical condensation point, water droplets form out of the water vapour in the air onto the colder surface. The air does not have to be that warm but you do need moist air meeting a colder than air surface that acts as a heat sink to the air that meets it. Rainy days provide the moist atmosphere, steel materials, concrete, thin cladding materials, glass, slate and tile all meet the requirement of a fast conducting heat sink that will allow condensation to occur.

Concrete constructed buildings such as car parks are not typically heated and rely on natural ventilation to keep condensation at bay. Where ventilation is poor or the ventilation is overwhelmed by the magnitudes of relatively moist air and cold heat sink expanse condensation is an ever present risk. This problem can largely be overcome by spraying a polyurethane foam anti condensation coating. By insulating the heat sink building material so that its relative heat conduction ability is impaired to stop water vapour dropping in average energy when coming into contact with it condensation is prevented.  It’s a very much a case of presenting a ‘warm surface’ aka a warm roof to the air where condensation is prone to occur.

Car park roofs, steel sheets, concrete soffits and ceilings, steel sheets, asbestos cladding are all favourites for spray foam treatment to prevent condensation. Farmer’s crop buildings, potato and crop sheds, dry storage buildings and other types of structures where condensation would otherwise ruin the stored goods can be easily retro sprayed using spray foam. The requirement is not for thermal heat insulation but for an anti-condensation solution. The solution is in effect a warm roof that stays sufficiently warm not to cause thermal conduction to the point that heat energy from the air is lost rapidly.

In the case of car parks a further requirement must be met. Because of the increased fire risk in car parks the British Standard Class 1 foam is over coated to with a Class 0 material to provide a Class 0 barrier. This avoids future problems and increases the safety aspect of the application.

To achieve an anti-condensation coating it is normally sufficient to spray between 25 to 40 mm of polyurethane foam. At 40 mm a U value of circa 0.52 will be achieved which clearly will not meet modern standards for thermal insulation but does nevertheless achieve a certain insulation value. More foam can be applied if Building Regulations are to be met and 100 mm on a concrete soffit will typically produce a U value of 0.25. This is usually the case when a car park is constructed under a residential building and cast reinforced concrete forms the ceiling of the car park and the 1^st floor of the building. This design is a condensation and thermal insulation problem but easily solved by spray foam polyurethane.