Whether it’s slimy black spots on your shower curtain, green mould in your fridge seal or slick orange film that forms on your kitchen drain, household mould is more than unsightly. In some cases, mould in your home can make you sick, especially if you have allergies or asthma.
Whether or not you’re allergic to moulds, mould exposure can irritate your eyes, skin, nose, throat, and lungs. Here’s what you can do to combat mould problems, and take care of yourself and your home.
Who’s at risk from mould?
For people sensitive to mould, inhaling or touching mould spores can cause allergic reactions, including sneezing, runny nose, red eyes and skin rash. People with serious mould allergies may have more severe reactions, including shortness of breath. In people with asthma who are allergic to mould, breathing in spores can also cause asthma attacks.
In addition to people with allergies and asthma, others who may be more sensitive to the effects of mould include:
- Infants and children
- The elderly
- People whose immune systems are compromised due to HIV infection, cancer,liver disease, or chemotherapy
- People with chronic lung disease
What is mould?
Moulds are small organisms found almost everywhere. They can be black, white, orange, green or purple. Outdoors, moulds play an important role in nature, breaking down dead leaves, plants and trees. Moulds thrive on moisture and reproduce by means of tiny, lightweight spores that travel through the air. You’re exposed to mould every day.
In small amounts, mould spores are usually harmless, but when they land on a damp spot in your home, they can start to grow. When mould is growing on a surface, spores can be released into the air where they can be easily inhaled. If you’re sensitive to mould and inhale a large number of spores, you could experience health problems.
Where do moulds grow?
Your walls, floors, appliances, carpet or furniture can all provide the food mould needs to grow. But the thing all moulds need most is moisture, so you’re most likely to see mould in damp places such as bathrooms, kitchens, utility rooms and cellars.
Top tips for controlling mould
It’s impossible to get rid of all mould and mould spores in your home, but because mould spores can’t grow without moisture, ventilation and reducing moisture in your home is the best way to prevent or eliminate mould growth. If there is already mould growing in your home, it’s important to clean up the mould and fix the problem causing dampness. If you clean up the mould but don’t fix the problem, the mould will probably return.
He are some moisture-reducing tips for the areas most prone to dampness and mould growth:
- Keep indoor humidity at 50% or less if possible. You can measure relative humidity with an inexpensive device called a hygrometer.
- Use dehumidifiers to reduce moisture in the air. Remember to empty and clean the reservoir regularly.
- Keep the house warm in cool weather. As the temperature goes down, the air is less able to hold moisture and it condenses on cold surfaces, which can encourage mould growth.
- Add insulation to cold surfaces, such as exterior walls, floors and windows to reduce condensation.
- Dry any wet areas within 24 to 48 hours to prevent mould growth.
- Fix leaks and seepage. The ground should slope away from your house. If water is entering the house from the outside, your options range from simple landscaping to extensive excavation and waterproofing.
- Make sure gutters are cleared and working properly.
- Open doors between rooms to increase circulation, which carries heat to cold surfaces.
- The NHS recommends opening the bedroom window for 15 minutes each morning.
In the kitchen:
- Use extractor fans to move moisture outside whenever you are cooking, washing dishes or cleaning.
- Check for leaks around the kitchen sink, fridge and freezers and other sources of water. Repair if necessary.
- Empty and clean fridge drip trays if necessary.
- Put lids on saucepans.
In a utility room:
- Vent your tumble dryer to the outside.
- Make sure the vent is clear of obstructions, such as lint, and that there are no holes that leak air. If the vent duct is damaged, replace it with a metal duct. Have the duct cleaned at least once a year.
- Avoid leaving damp clothes in the laundry basket or dryer. Wash and dry them promptly.
- Try to avoid drying damp clothes indoors, by, for example, hanging over radiators.
- Use extractor fans to remove moisture to the outside.
- Check for leaks around basins and baths and have them repaired if necessary.
- Close the bathroom door and open a window when showering.
- Avoid leaving damp towels on the floor or in a laundry basket.
Is your home damp? Damp can cause mould on walls and furniture and make window frames rot. Damp cold housing encourages the growth of mould and mites, as mites feed on moulds and can increase the risk of respiratory illnesses in some people.
Some damp is caused by condensation. This leaflet explains how condensation forms and how you can keep it to a minimum, so reducing the risk of dampness and mould growth.
First steps against condensation
You will need to take proper steps to deal with the condensation, but meanwhile there are some measures you can take right away.
Wipe down the windows and sills every morning. Wring out the cloth rather than drying it on a radiator.
Condensation channels and sponge strips can be bought at DIY shops. They are fitted to windows to collect the condensation and thus help prevent window frames from rotting and avoid damp forming under sills. Care must be taken to fit these devices properly.
First steps against mould
First treat the mould already in your home. If you deal with the basic problem, mould should not reappear.
To kill and remove mould, wipe down walls and window frames with a fungicidal wash which carries a Health and Safety Executive ‘approval number’. Follow the manufacturer’s instructions precisely. Dry-clean mildewed clothes, and shampoo carpets. Disturbing mould by brushing or vacuum cleaning can increase the risk of respiratory problems.
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.
The only lasting way of avoiding severe mould is to eliminate dampness.
Is it condensation?
Condensation is not the only cause of damp. It can also come from:
- Leaking pipes, wastes or overflows.
- Rain seeping through the roof where a tile or slate is missing, spilling from a blocked gutter, penetrating around window frames, or leaking through a cracked pipe.
- Rising damp due to a defective damp-course or because there is no damp-course.
These causes of damp often leave a ‘tidemark’ and you should have the necessa ry repairs carried out to remove the source of damp.
If your home is newly built it may be damp because the water used during its construction (e.g. in plaster) is still drying out.
If your home is damp for any of these reasons it may take weeks of heating and ventilating to dry out. Hiring a dehumidifier will help.
If you do not think the damp comes from any of these causes, it is probably condensation
What is condensation?
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. This is condensation. You may notice it when you see your breath on a cold day, or when the mirror mists ove r when you have a bath.
Condensation occurs mainly during cold weather, whether it is raining or dry. It does not leave a ‘tidemark’. It appears in places where there is little movement of air. Look for it in corners, on or near windows, in or behind wardrobes and cupboards. It often forms on north-facing walls.
How to avoid condensation
T hese four steps will help you reduce the condensation in your home.
1. Produce less moisture
Some ordinary daily activities produce a lot of moisture very quickly.
Cooking: To reduce the amount of moisture, cover pans and do not leave kettles boiling.
Paraffin and portable flueless bottled-gas heaters: These heaters put a lot of moisture into the air – one gallon of gas or paraffin produces about a gallon of water. If you have a problem with condensation, try to find alternative means of heating.
Washing clothes: Put washing outdoors to dry if you can. Or put it in the bathroom with the door closed and the window open or fan on. It is best to fit a fan that can be switched to run continuously for clothes drying. If you have a tumble dryer make sure you vent it to the outside (unless it is the self-condensing type). DIY kits are available for this.
2. Ventilate to remove the moisture
You can ventilate your home without making draughts.
Some ventilation is needed to get rid of moisture being produced all the time, including that from people’s breath. Keep a small window ajar or a trickle ventilator open all the time if possible, and especially when someone is in the room.
You need much more ventilation in the kitchen and bathroom when cooking, washing up, bathing and drying clothes. This means opening the windows wider. Better still, use a humidistat-controlled electric fan (these come on automatically when the air becomes humid and are cheap to run).
Close the kitchen and bathroom doors when these rooms are in use even if your kitchen or bathroom has an extractor fan. It will help to draughtproof these doors. Doing this will help stop the moisture reaching other rooms, especially bedrooms, which are often colder and more likely to get condensation.
Allow space for the air to circulate in and around your furniture. 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.
When you have a curtain or blind drawn, it makes the surface of the window cooler and increases condensation, especially with single glazed windows. Trickle ventilators can help reduce the problem. If you replace your windows at any time, make sure they are double glazed and fitted with trickle ventilators.
3. Insulate and draughtproof
Insulation in the loft, cavity wall insulation and draughtproofing of windows and outside doors will help keep your home warm and you will have lower fuel bills as well. When the whole home is warmer, condensation is less likely.
- Do not block permanent ventilators.
- Do not completely block chimneys (leave a hole about two bricks in size and fit a louvred grille over it).
- Do not draughtproof rooms where there is a fuel burning heater (e.g. gas fire) or cooker.
- Do not draughtproof windows in the bathroom or kitchen.
If you live in a house, insulating your loft is a cost-effective way of cutting heating costs. Remember to draughtproof the loft hatch but do not block any eaves ventilation. Cavity wall insulation is also an effective way of cutting heating costs. Many properties, however, are built without suitable cavities. If you are in doubt, you should seek the advice of a building professional who will advise you on the need for a building warrant.
Secondary glazing of windows reduces heat loss and draughts but you must ensure that there is some ventilation and adequate means of escape in an emergency such as a fire. Remember that any alteration to your windows, including their replacement, must meet the relevant requirements of the Building Standards (Scotland) Regulations. You should consult you local authority on the need for a building warrant before any work is undertaken.
4. Heat your home a little more
In cold weather, the best way to keep rooms warm enough to avoid condensation is to keep low background heating on all day, even when there is no one at home. This is very important in flats and bungalows and other dwellings where the bedrooms are not above a warm living room. If you have central heating set it to provide background warmth in all rooms including unused rooms.
Otherwise install suitable thermostatically-controlled heaters where necessary (do not use paraffin or flueless bottled gas heaters for this purpose). The thermostats will help control heating and costs. Remember to provide background ventilation at the same time.
Dehumidifiers will help dry out damp in newly built houses. They can also help reduce condensation but they are of limited use in cold damp rooms.