Condensation

Condensation problems occur when warm moist air comes in contact with cooler surfaces and black mould appears. Condensation symptoms may well be visibly evident long after the event has occurred. Winter condensation damage may well leave long lasting visible evidence. All buildings have a degree of moisture always present in the air, breath, perspiration, warm washing water, clothes driers, showering, boiling water for tea or coffee, to name but a few sources of warm water vapour. Walls, windows and ceilings provide a temperature or heat barrier, normally warmer on one side than the other. At the interface between warm moist air and cooler walls and windows, the water vapour will be cooled becoming liquid again, creating fine droplets. Readily seen on glass surfaces, more porous materials, such as wood and plaster, will provide some measure of absorption - a haven for airborne mould spores - thus encouraging mould growth.

Poorly ventilated external masonry wall cavities can also suffer from condensation occurring within the cavity and without adequate air flow the condensed water vapour can saturate masonry quite quickly. This can often be determined by using an electronic moisture meter on the external wall surface. Higher readings may be revealed below brick window sills and mid-way between external brick vents. In many instances the masonry will be visibly wetter, (darker in colour), above the damp-course level.
Damp readings found higher up on wall surfaces, in corners, near or on the ceiling, behind paintings, wall hangings, bed-heads and wall furniture, partially drawn drapes and poorly heated and ventilated rooms, would indicate condensation.
The dissolved salt content in true “rising damp” discourages mould growth. Mould spores being sensitive to salt contaminated materials.

Visible  Symptoms

• Mould & algae growth
• stained walls
• delaminating wallpaper
• rotting timber skirting-boards and doorframes.