What Is The Difference Between Damp And Condensation?
Damp occurs when a fault in the building’s basic structure lets in water from outside. There are basically two types of damp
This occurs if water is coming in through the walls or roof, (for example, under a loose roof tile) or through cracks.
This occurs if there is a problem with the damp proof course. This is a barrier built into floors and walls to stop moisture rising through the house from the ground. The usual evidence of rising damp is a ‘tide mark’ on the walls that shows how high it has risen and sometimes an accompanying musty smell. Rising damp cannot travel higher than 1.2m up a wall. Once the water reaches this height, it is naturally limited by its own weight, and the act of gravity.
There is always some moisture in the air, even if you cannot see it. If air gets cold, it cannot hold all the moisture produced by everyday activities and some of this moisture appears as tiny droplets of water, most noticeable on windows on a cold morning. This is condensation. It can also be seen on mirrors when you have a bath or shower, and on cold surfaces such as tiles or cold walls. If damage has been caused to the property because tenants have not properly managed condensation, then repairs can be charged to the tenants.
Condensation occurs in cold weather, even when the weather is dry. It doesn’t always leave a ‘tidemark’ round its edges on walls. If there is a ’tidemark’, this dampness might have another cause, such as water leaking into your home from a plumbing fault, loose roof tiles or rising damp. Look for condensation in your home. It can appear on or near windows, in corners and, in or behind wardrobes and cupboards. Condensation forms on cold surfaces and places where there is little movement of air.
Problems that can be caused by excessive condensation
Dampness caused by excessive condensation can lead to mould growth on walls and furniture, mildew on clothes and other fabrics and the rotting of wooden window frames. Also, damp humid conditions provide an environment in which house dust mites can easily multiply.
First steps against condensation
You will need to take proper steps to deal with condensation, but meanwhile there are some simple things you should do straight away. Dry your windows and windowsills every morning, as well as surfaces in the kitchen or bathroom that have become wet. Wring out the cloth rather than drying it on a radiator.
First steps against mould growth
First treat the mould already in your home, then deal with the basic problem of condensation to stop mould reappearing. To kill and remove mould, wipe down or spray walls and window frames with a fungicidal wash that carries a Health and Safety Executive (HSE) ’approval number’, and ensure that you follow the instructions for its safe use. These fungicidal washes are often available at local supermarkets. Dry-clean mildewed clothes, and shampoo carpets. Do not try to remove mould by using a brush or vacuum cleaner. After treatment, redecorate using good-quality fungicidal paint and a fungicidal resistant wall paper paste to help prevent mould recurring. The effect of fungicidal or anti-condensation paint is destroyed if covered with ordinary paint or wallpaper.
But remember: the only lasting cure for severe mould is to get rid of the dampness.
What causes condensation?
There are four main factors that cause condensation:
Too much moisture being produced
Not enough ventilation
You need to look at all of these factors to cure a condensation problem.
Too much moisture being produced
Our everyday activities add extra moisture to the air inside our homes. Even our breathing adds some moisture (remember breathing on cold windows and mirrors to fog them up?). One person asleep adds half a pint of water to the air overnight and at twice that rate when active during the day. To give you some idea as to how much extra water this could be in a day, here are a few illustrations
2 people at home (just breathing!) can produce = 3 pints
A bath or shower = 2 pints
Drying clothes indoors = 9 pints
Cooking and use of a kettle = 6 pints
Washing dishes = 2 pints
Total moisture added in one day = 22 pints
Reduce the potential for condensation by producing less moisture
Hang your washing outside to dry if at all possible, or hang it in the bathroom with the door closed and a window slightly open or extractor fan on.
Don’t be tempted to put it on radiators or in front of a radiant heater. Always cook with pan lids on, and turn the heat down once the water has boiled.
Only use the minimum amount of water for cooking vegetables. When filling your bath, run the cold water first then add the hot - it will reduce the steam by 90% which leads to condensation.
If you use a tumble drier, make sure it is vented to the outside or that it is of the new condensing type and that the pipe is not obstructed of the reservoir full. Don’t use your gas cooker to heat your kitchen as it produces moisture when burning gas. (You might notice your windows misting over).
Ventilating your home
Ventilation can help to reduce condensation by removing moist air from your home and replacing it with drier air from outside. Help to reduce condensation that has built up overnight by ’cross- ventilating’ your home - opening to the first notch a small window downstairs and a small one upstairs. (They should be on opposite sides of the house, or diagonally opposite if you live in a flat). At the same time, open the interior room doors, this will allow drier air to circulate throughout your home. Cross-ventilation should be carried out for about 30 minutes each day
Make sure that accessible windows will not cause a security problem - remember to close them when you go out.
Ventilate your kitchen when cooking, washing up or washing by hand. A window slightly open is as good as one open. If you have one, use your cooker extractor hood or extractor fan.
Ventilate your kitchen and bathroom for about 20 minutes after use by opening a small top window. Use an extractor fan if possible - they are cheap to run and very effective.
Ventilate your bedroom by leaving a window slightly open at night, or use trickle ventilators
if fitted. (But again, remember your security). Keep kitchen and bathroom doors closed to prevent moisture escaping into the rest of the
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 wardrobes and cupboards, as it restricts air circulation.
Condensation forms more easily on cold surfaces in the home, for example walls and ceilings. In many cases, those surfaces can be made warmer by improving the insulation and draught-proofing. Insulation and
draught-proofing will also help keep the whole house warmer and will cut your fuel bills. When the whole house is warmer, condensation becomes less likely
Warm air holds more moisture than cooler air which is more likely to deposit droplets of condensation round your home. Air is like a sponge; the warmer it is, the more moisture it will hold. Heating one room to a high level and leaving other rooms cold makes condensation worse in the unheated rooms. That means that it is better to have a medium-to-low level of heat throughout the house. Keeping the heating on at low all day in cold weather will help to control condensation, but keep a check on your meters to check how much it is costing you. If you don’t have heating in every room, you could keep the doors of unheated rooms open to allow some heat into them.
If you need more help just ask.