On this page

Introduction

Damp, condensation, and mould in your home can be bad for your health, especially if you have a respiratory condition. There are a few things you and your landlord can do to reduce damp and mould. If your landlord doesn’t make necessary repairs, you can report the problem to us.

What are damp, condensation and mould?

What is damp?

Damp is caused by excess moisture in a building. The excess moisture makes its way into the property from outside (penetrating damp / rising damp). Rising damp is caused by ground water moving up through a wall or floor. Penetrating damp is caused by leaking water. It’s usually caused by structural problems in a building, such as faulty guttering, or it can be caused by internal leaks, like pipes under the sink. This type of damp may expand across walls or a ceiling horizontally.

What is condensation?

Condensation occurs when the air and/or surfaces are cold and when the moisture content of the air is high. There is always some moisture in the air, even if you cannot see it. If the air gets colder, it cannot hold all the moisture and tiny drops of water appear on cold surfaces, typically windows. It is noticeable when you see your breath on a cold day, or when the mirror mists over when someone is having a bath or shower.

Damp or humid conditions are perfect conditions for mould to grow

What is mould?

Black Mould is a type of fungus that grows in damp conditions. Depending on the severity the mould can vary in appearance. Black mould produces spores which allows mould to keep reproducing and growing. Mould spores are tiny structures produced by mould to reproduce and grow and are responsible for most health problems caused by damp and mould in the home. The spores are incredibly small and cannot be seen which means that they can float undetected in the air. These spores are allergens, which cause various allergic reactions. Inhaling or touching mould spores can cause health issues or make existing conditions worse.

Therefore, reducing damp and condensation can reduce mould growth.

How to tackle the problem

Damp

Damp-proof protective material (sometimes called a ‘course’ or ‘membrane’) usually stops the water from rising walls and causing damage. Penetrating dampness is usually caused by structural problems in a building, such as faulty guttering, or it can be caused by internal leaks, like pipes under the sink. This type of damp may expand across walls or a ceiling horizontally and can be remediated by building works

Condensation

Reducing condensation does not require much effort:

  • Open windows or put on the extraction fan when you’re showering or bathing
  • Put lids on saucepans and use the extraction hood
  • Regularly ventilate your home and leave doors open to let air circulate – Opening windows for 15 minutes each morning is a good way to reduce build-up of moisture.

Once you reduce the moisture in your home, the chances of black mould growing are slim. But if mould does start to appear, especially in the cold months it should be killed and removed by following the steps below:

  1. Wipe down walls, ceilings, and window frames with a fungicidal wash, which carries a Health and Safety Executive ‘approval number’. Follow the manufacturer’s instructions precisely. Allow surfaces to dry.
  2. Dry-clean mildewed clothes, and shampoo carpets. Disturbing mould by brushing or vacuum cleaning can increase the risk of respiratory problems and must be avoided.
  3. After treatment redecorate using a good quality fungicidal paint to help prevent mould. Note that this paint is not effective if overlaid with ordinary paints or wallpaper. When wallpapering, use a paste containing a fungicide to prevent further mould growth.

Mould

The only way of avoiding severe mould is to minimise the risk by:

  • Reducing the amount of moisture when cooking by covering pans and not leaving kettles boiling.
  • Not using paraffin and portable flueless bottled gas heaters as they produce a lot of moisture into the air.
  • Placing washing outdoors to dry if possible. If the only option is to dry clothes inside, put them in the bathroom with the door closed and the window open or fan on. If using a tumble dryer, ensure it is venting outside (unless it is the self-condensing type).
  • Keeping a small window ajar or a trickle ventilator open all the time, especially when someone is in the room.
  • Ensuring that the property has more ventilation in the kitchen and bathroom when cooking, washing up, bathing and drying clothes - this means opening the windows wider and switching on a fan. Where there is no fan, one should be installed.
  • Open doors to ventilate cupboards and wardrobes. Leave space between the backs of wardrobes and the wall.
  • Where possible, position wardrobes and furniture against internal walls, i.e., walls which have a room on both sides, rather than against outside walls
  • Installing insulation in the loft and cavity wall to keep home warm and reduce fuel bills
  • In cold weather, keep rooms warm enough to avoid condensation by keeping low background heating on all day, even when there is no one at home. Where there is central heating, set it to provide background warmth to all rooms including unused rooms. If fitted, thermostatically controlled radiator valves (TRVs) can be used to control heating and costs.

Report it

If you still have damp, mould and condensation after following these steps, report it to Merton Housing Enforcement Team.

If you are renting from a private landlord or from a housing association, we can investigate complaints about housing conditions such as disrepair, dangerous conditions, or absence of hot water.

Housing Enforcement
Merton Civic Centre
London Road
SM4 5DX

Telephone: 020 8545 3212
Email: ehhousing@merton.gov.uk