Definitions
Condensation: occurs when moisture held in warm air meets a cold surface and produces water droplets when condensing. This can take two main forms:
- Surface condensation arising when the inner surface of the structure is cooler than the room air.
- Condensation inside the structure where vapour pressure forces water vapour through porous materials, e.g., walls which then condenses when it reaches colder conditions within the structure.
The effects can be a challenge, particularly during winter months and in most cases is one we need to work with tenants on to manage through the effective use of heating and ventilation. Conditions that can increase the risk of condensation include:
- Inadequate ventilation e.g., natural opening windows and trickle/background vents, and mechanical extraction in bathrooms and kitchens.
- Deficient heating of property that could include small boilers, radiators, and lack of draught proofing.
- Poor thermal insulation.
- High humidity, a presence of rising and/or penetrating damp.
- Poor building design and construction.
- Unsatisfactory venting of tumble driers that can create increased humidity.
- Drying of washing on radiators and clothes airers that can increase humidity.
- Lack of mechanical ventilation use during bathing and cooking.
- Radiators and good air flow circulation being blocked by large items of furniture.
Mould is a form of fungus that is produced in damp and humid conditions. It can be caused through humidity, condensation, rising damp and poor ventilation. Mould can appear in different forms and is predominately black or green.
If remedial work is not undertaken or prevention and control measures are not followed to mitigate condensation and mould, then damp related issues may occur.
Damp can either be penetrative or rising:
Penetrating damp can be caused through water entering the external structure or internal leaks within a property causing damp, rot, and damage. Once the source is located, repairs should be straightforward, although it can take some time for the area to dry out. This type of damp can be caused by:
- Water ingress due to defective or poor building design and/or work quality.
- Defective components such as roof coverings, external wall doors or windows.
- Faulty or blocked rainwater gutters and pipes.
- Substandard or leaking internal waste pipes, and heating systems.
- Flooding due to burst pipes.
Rising damp is caused by the breakdown, deterioration or bridging of the damp proof course of the building at ground level. Moisture then rises up the walls, this can be to a maximum of one metre.
Rising damp can be identified by a coloured tide mark, often textured. The texture is caused by salt from the ground and the plaster being drawn through the wall with the water.