What is Condensation?

There are three main factors that cause condensation:

• Too much moisture being produced in the property
• Insufficient ventilation within the property
• Cold surfaces

You need to look at all of these factors to manage a condensation problem.

Moisture or water in the air is produced by normal household activities like cooking, bathing and even breathing. It is always in the air even if you cannot see it. This moist air travels through the property.

Condensation usually occurs during cold weather and will be worse in places where there is little air movement such as corners of rooms and behind furniture if near an external wall.

When warm moist air hits a cold surface such as a mirror, window or a cold part of a wall near a window, condensation is generated as the moisture condenses into droplets on the surface. When this happens on your window, the glass mists up and drops of water run down the window.

When it happens on a wall or ceiling, the surface soaks up the moisture and becomes damp. Mould could then grow on the damp areas. Mould growth can contribute to health problems for occupants such as asthma and other respiratory diseases.

As well as affects on health, condensation in housing can also lead to the deterioration of building finishes and fabrics, which can lead to increased maintenance and management costs.

Condensation is one of a number of causes of damp in properties and occurs even when the weather is dry. It does not leave a 'tidemark' round its edges on walls. If there is a 'tidemark', this dampness might have another cause, such as:

• Missing slates or tiles from a roof
• Leaking or blocked gutters
• Leaking and blocked down pipes and overflows
• Leaks form internal plumbing and plumbing appliances
• Dampness rising up walls from the ground, often from bridging of the damp-proof course

How can you produce less moisture?

To tackle condensation, a balance of measures must be used including improving the insulation and ventilation in your property and making sure there are less cold areas.

Moisture production is influenced by the design, construction, disrepair of the property and also the number of occupants and activities undertaken within the property.
Some simple changes in lifestyles and the occupation of properties can help reduce condensation as well as being more energy efficient. Examples of these are;

  • Wipe away excess moisture from windows and windowsills every morning and wring out the cloth. (Just letting it dry out will put the moisture back into the air)
  • Dry clothes outdoors on a line whenever possible. If using a tumble dryer ensure it is either a condensing unit or that any vent is vented to the outside. If neither option is available put the clothes in one room to dry with the door closed ensuring that the window is open to encourage excess moisture to escape.
  • Cook with pan lids on and open kitchen windows or use the extractor fan when cooking. Turn the heat down once the water has boiled. Use a steamer or only use the minimum amount of water for cooking. 
  • Do not use your gas cooker to heat your kitchen as it produces moisture when burning gas.
  • Open windows or use the extractor fan when cooking, bathing or showering and keep the doors to the rooms closed. Once you have finished in the room leave a window open slightly to allow excess moisture to escape, and ensure the door is closed behind you.
  • When running a bath, put some cold water in first then add hot. This reduces the steam by 90%.
  • To reduce the risk of mildew on clothes and other stored items, allow air to circulate round them by removing 'false' wardrobe backs or drilling breather holes in them. You can place furniture on blocks to allow air to circulate underneath. Keep a small gap between large pieces of furniture and the walls, and where possible place wardrobes and furniture against internal walls. Pull shelves away from the backs of wardrobes and cupboards. Never overfill wardrobe and cupboards, as it restricts air circulation.
  • Don’t keep furniture and beds hard against walls, make sure air can circulate.
  • Keep your heating on low throughout the day in cold weather as an even temperature reduces cold spots.
  • If you do not have heating in every room, you could keep the doors of unheated rooms open to allow some heat into them.
  • To add extra heat to rooms without any form of installed heating, it is better to use electric heaters, for example oil-filled radiators or panel heaters, on a low setting. Remember, you should not use portable bottled gas heaters in homes suffering with condensation as they give out a lot of moisture whilst in use. It is actually cheaper to heat a room with on-peak electricity than by using bottled gas heaters.
  • Ventilate your bedroom by leaving a window slightly open at night, or use the trickle ventilators if fitted.
  • If you have trickle vents installed above windows, keep them open all the time. This allows air to circulate around the property.
  • Don’t block air vents or air bricks, they are there to circulate air through the property. Blocking them prevents the moisture from escaping. Be careful not to 'over-ventilate' your home when it is cold, as it will cause the temperature inside your home to drop and make condensation more likely. It will also increase your heating costs.

What else can be done?

Condensation occurs on cold spots, so if you can warm up the cold spots you can reduce the condensation.

Insulating your loft, external walls and draught proofing doors and windows will help to reduce cold spots and also help reduce energy bills as the home will be cheaper to heat.

Ensure your property has suitable cavity wall and loft insulation where possible to reduce the number of cold surfaces where condensation can form. Older properties may require more work in providing additional insulation.

Provide safe and suitable heating in your property with timer and temperature controls. Ensure it is serviced annually and ensure that occupiers understand how to use the heating system in your property.

Keep the property warm naturally. Don’t trap heat. Avoid placing large pieces of furniture in front of a radiator as this prevents the heat from circulating. Keep curtains above radiators as thick curtains can stop heat escaping and remember to close them at dusk. Keep curtains open on sunny days to help warm rooms and keep doors open in rooms that get lots of sunlight as this will allow the warm air to circulate in your home.

Try to avoid having cold areas in the home. If you have a condensation problem it is better to heat the whole home to a lower temperature, rather than one room to a very high temperature. When you get condensation forming it is often not in the room where you are making the moisture, for example, kitchens and bathrooms, but in a room you don’t often use, like a spare bedroom. This is because the room is usually not heated. Try heating rooms regularly.

By providing suitable ventilation to the property this will allow excess moisture to escape. Special attention should be paid in rooms such as bathrooms and kitchens. Ensure that the windows in these rooms can be opened, and, where possible, provide extractor fans not just a re-circulating fan that are often fitted above cookers. You can see if the cooker hood fax extracts to the outside by checking the wall from outside to see the vent.
Ensure that occupants understand how to correctly use extractor fans, vents and opening the windows, and the benefits this can achieve. Ensure that existing air vents and air bricks are not blocked, or decorated over, and that trickle vents on windows and doors work correctly.

You can also ensure that damp is not being caused or made worse by leaking central heating or waste pipes, defective rainwater pipes/gutters, drains, toilets or a failed damp proof course or defective rendering.

How do I remove mould growth from within the property?

The best way of tackling mould is to reduce the condensation levels and prevent it growing in the first place.

Mould can be easy to remove. You can normally wipe it off with a disposable cloth using some household cleaner or bleach solution. There is no need to use strong chemicals. Wipe over the area again every few days using diluted household cleaner to stop the mould growing back. This should become part of your regular cleaning routine. Dry-clean mildewed clothes, shampoo carpets. Do not try to remove mould by using a brush or vacuum cleaner as this can release spores and increase the risk of breathing problems.

If the mould seems persistent you can wash down or spray mould-affected walls, ceilings and paintwork with a fungicidal wash (Mould & Mildew remover) that carries a Health & Safety Executive (HSE) approval number, and ensure you follow the instructions for safe use. These fungicidal washes are often available at local supermarkets or Do it yourself outlets. Follow the manufacturer’s instructions precisely.

In more severe cases where wiping areas down as detailed above is insufficient or the mould has taken hold into the wall coating, you may need to strip wall and ceiling paper from the mould affected rooms.

After treatment, redecorate using a good quality fungicidal paint and a fungicidal resistant wallpaper paste to help prevent the mould from recurring. The effect of fungicidal or anti-condensation paint is destroyed if covered with ordinary paint or wallpaper.

Once the mould has been removed then you can deal with the basic problem of condensation to stop mould from reappearing.

What help can I get with heating, insulation and ventilation?

There are some national grant schemes towards efficient heating and insulation. Please contact the Energy Advice Centre called ActonEnergy on 01789 842898 who can provide free advice on what is currently available.

Wyre Forest District Council has recognised that some tenanted properties need ventilation improvements to help reduce condensation issues and recommend landlords fit humidistat fans that are switched on and off automatically by the level of moisture in the air. We may be able to provide some financial assistance to get these fitted, normally where tenants are on benefits. Call Private Sector Housing on 01562 732928.

For owner occupied properties on benefits or low income, we may be able to help fund needed repairs and improvements through a loan scheme whereby the cost of works is placed as a charge on the property. Please contact Care and Repair Worcestershire on 01684 579456.