Think Fungus: Laundry

The evidence that damp homes are harmful to our health continues to build with recent reviews concluding that there is strong or causal evidence that damp homes have a big impact on causing and worsening asthma, severe asthma and allergy (1).

Damp is thought to afflict large numbers of our homes with some estimates suggesting more than 40% of rented homes in the UK have difficulties. We clearly have a major problem on our hands!

The vast majority of damp problems in the home are caused by excessive moisture in indoor air and lack of ventilation to remove that damp air. Some find that opening windows to let our damp air when cooking or showering is sufficient to prevent damp but that advice often goes unheeded especially when the outside temperature is cold and the occupants need to stay warm. There are mechanical ventilation options but those remain unpopular as they can be expensive to fit,  negating any cost savings due from no longer having to open windows.

An alternative strategy is to identify sources of moisture in the home and to try to eliminate them. Some we cannot (cooking, showering) but some have a major impact on indoor air moisture without us realising it.

A study in Ireland (2) has measured the major sources of indoor air moisture as follows:

A  person could perspire and exhale (grams of water)

  • 40 g of water vapour per hour when sleeping
  • 70 g/h when seated
  • 90 g/h when standing or doing housework.

Weight of water vapour (i.e. moisture) released by various domestic activities (grams of water):

  • Cooking with gas cooker: 3,000 g/day
  • Cooking with electricity: 2 000 g/day
  • Dishwashing: 400 g/day
  • Washing clothes: 500 g/day
  • Drying clothes indoors: 1,500 g/day
  • 15 minute shower: 600 g per person

Clearly other than cooking the biggest contributor to indoor air moisture in this list is drying laundry indoors. This hidden danger probably plays a big part in promoting damp in our homes, and causing the many health problems associated with damp. Householders should keep that moisture out of the home and if landlords fail to provide adequate facilities to move the moisture generated by drying laundry out of the home before it can cause problems then they themselves are contributing to the damaging ‘lifestyle choices’ that many of them claim is causing the damp and damage to their properties.

  1. Indoor environmental exposures and exacerbation of asthma: an update to the 2000 review by the Institute of Medicine. 2015
  2. Damp and mould in Irish Homes 2016