Condensation, Damp and Mould
Mould Growth, Dampness & Condensation
Mould growth, dampness and condensation are very common problems in UK homes, and particularly in Rental Properties. Dampness and mould are the biggest single cause of complaints to local authorities from their own tenants.
There are four main causes of Mould Growth, Dampness and Condensation:
Ingress of Water
Ingress of water into the building due to structural defects and maintenance problems:
- Leaking roofs, gutters and spouts
- Blocked or inadequate drains
- Ineffective damp proof courses causing rising damp
- Through underground walls in basements & cellars
- Defective pointing and masonry
- Leaks from doors and windows
- Leaking internal plumbing
- Flooding and bursts
Where the building itself is not insulated to modern standards, particulalry in older properties with solid (not cavity) walls, the sturture of the building including walls, floors and roofspaces presents cold surfaces which exacerbates condensation and mould problems.
2- Insufficient Ventillation
Insufficient ventilation due to design or maintenance problems:
- Inadequate air flows under floors and in attic spaces
- Inadequate internal ventilation and air circulation – allowing stagnant air pockets in some rooms.
- Inadequate extraction of moist air (steam) from kitchens, bathrooms and clothes drying.
Where a house is left without heating or has inadequate heating for prolonged period, the fabric of the building becomes cold and therefore absorbes moisture at a much higher rate.
The first two are building ralated and come down to maintanance and repairs on the part of the landlord. On the other hand, although a tenant can expect a minimum stanard, a tenant cannot demand that their tenancy be brought up to the very latest standards.
The second two causes, although the landlord can influence these, they are often down to the tenant as well.
The Effects of Condensation
All modern houses will have some condensation but excessive condensation is often down to the lifestyle of the tenants rather than any serious defects in the property.
Tenants will often point the finger directly at the landlord when in fact their condensation problem is of their own making:
- They spend little time in the house/flat during the daytime so it is not adequately heated.
- When they arrive home in the evening all the energy producing activity is concentrated into a small time envelope –
- Cooking, which produces heat and steam
- Washing, bathing, showering, clothes drying, cleaning, all of which produce stream and warm air.
- They do not ventilate, by opening windows or by using extractor fans, which these conditions require.
Condensation occurs when warm moist air comes into contact with cold surfaces or cooler air. Warm, moist air will always travel towards colder air, and particularly up-stairs to bedrooms.
Condensation appears as moisture, particularly on non-porous surfaces such as windows and tiles, but also on painted walls and ceilings.
It often appears on the lower parts of outside walls which leads to confusion with rising damp – see Dampness.
Bedrooms and confined spaces such as wardrobes are particularly affected as these areas are the coldest and have no air circulation.