Moisture production is influenced by the design, construction and repair of the dwelling, and on occupant density and activity. Moisture is produced by occupants through their normal biological and domestic activities. Relatively low levels of moisture are generated through breathing and are spread out over the twenty-four hours. However, there are higher levels produced in peaks from cooking, clothes drying and bathing (or showering). Vapour pressure will equalize humidities throughout a dwelling, so that damp in one part will have an impact on relative humidities in other parts. The amount of water vapour that can be stored in the air can be increased simply by increasing the temperature. Things that landlord’s and agent’s can do to assist with preventing condensation in a home include:
The structure and finishes of a dwelling should be maintained free from rising, penetrating and traumatic dampness, or persistent condensation.
Increase the size of any radiators so rooms get warm enough efficiently especially in bathrooms or kitchens. Commonly in bathrooms, a heated towel rail is provided but often these don’t produce sufficient heat for the size of the room.
There should always be an extractor fan installed in particular in bathrooms and kitchens. Where there is one, try increasing the overrun so that it stays on longer.
Increasing insulation in attics can assist with keeping the house and rooms warmer for longer periods. Ensure windows correctly open so as to allow large amounts of steam build up to escaper quickly. Educate tenants by providing a leaflet at the commencement of any tenancy. Many local authorities provide excellent leaflets – see for example leaflet by Haringey Homes http://www.homesforharingey.org/damp_leaflet.pdf
Tenants should be advised to do the following to assist with the control of condensation (which might be included in a good leaflet):
When cooking or washing, open windows or use extractors.
Where drying clothes inside is necessary (preferable to dry clothes outside), do so in a small room with windows open.
Open windows for a while each day or use the trickle/night vents.
Do not block air vents – this is also important where gas and heating appliances are concerned as they need a supply of oxygen to work effectively and allow gases, such as carbon monoxide, to escape. Allow air to circulate around furniture and in cupboards – this can be done by making sure cupboards and wardrobes aren’t overfilled and there is space between the furniture and the wall.
When the whole house is warmer, condensation is less likely to form.
Maintain a low heat when the weather is cold or wet – this is more effective than short bursts of high heat.
Wipe down surfaces where moisture settles.
Cover boiling pans when cooking.
Close doors when bathing, showering or cooking to prevent steam going into colder rooms.