Tackle mould and condensation to feel more comfortable
Damp problems can be a serious concern in any home, whether you are a home-owner or renter, or living in any style of property. At best it can be a nuisance and make a room feel cold, unwelcoming and unhealthy, and at worst it can indicate structural or weatherproofing issues.
Fortunately, damp can often be treated and prevented without calling in the professionals. There are also easy signs to keep an eye out for that might indicate a problem, and simple strategies you can employ to reduce symptoms in your home.
In this guide, we’ll walk you through the process of identifying a damp problem and establishing its cause, and suggest how to repair and remedy so that you can enjoy your living space once again.
Tools & materials required
How to identify a damp problem
Damp problems are usually most apparent during the winter months, but you can look for warning signs at any time of year. The following checks should help you to identify the location of the problem;
Walls – Hold your hand against the wall, does it feel very cold or damp? Look for signs of mould or fungal growth which will appear as black speckled marks or grey growths on painted walls, woodwork and wallpaper. Flaking paint or curling wallpaper can also be an indicator.
Ceilings – As well as looking for signs of mould, pay close attention to the colour of the ceiling. Is it discoloured or stained in areas? Brown patches in the external corners and near chimney breasts can indicate damp.
Windows - Condensation on windows in the morning, along with small puddles of water along window sills, can indicate high moisture levels within your house. This can be both a cause, or symptom, of damp. Black mould may also develop on wooden and PVC window frames, and silicon sealant used around the edge of frames.
Bathrooms and kitchens – Inspect the grouting and sealant for signs of black mould. Check around window frames and on ceilings for similar damage. Look inside cabinets and cupboards to identify any areas of staining and mould growth, and pay attention to musty smells.
Furniture and soft furnishings – Black mould can grow on the inside of curtains, blinds and on upholstered surfaces such as sofas. Check the back of furniture for specks of mould and also for cloudy condensation on wooden and plastic surfaces.
Basements and unheated storage spaces – A musty, damp smell is likely to be first indicator of a problem here. In addition, check for staining and mould on painted walls and woodwork.
Causes of damp
In the majority of homes, damp is caused by one of four following issues;
Cause – Construction techniques and home renovations that have made it difficult for moisture to escape the building.
Symptoms - Condensation on windows, cold walls and surfaces (such as tiles) and a cool, damp feeling within your home.
Treatment - Reduce condensation, repair and prevent further damage from moisture.
Why does condensation develop in my home?
Moisture is generated in any house – through washing, cooking, drying laundry and even breathing. To keep your home feeling dry and comfortable, moist air needs a way to escape the building. If it can’t escape, it builds up within the home creating condensation.
This can happen in modern buildings, which are often well insulated and designed to keep warm air in, but don’t provide sufficient escape routes for moisture. It can also occur in older properties where the addition of new insulation, windows or doors has blocked or disrupted escape routes.
Cause - When the weatherproofing of a building lets you down. Common causes include leaking roofs (from broken or loose tiles, or damaged flashing on older buildings), leaking gutters (where the gutter has come loose or is blocked with leaves and debris) or damaged and deteriorating mortar, render or pebbledash on exterior walls.
Symptoms - The sudden appearance of a damp patch (that often looks like a brown stain) on the inside of an exterior wall, in the upper corners of a room, on a ceiling or near a chimney breast.
Treatment - Identify the source of the problem and make repairs to prevent further water ingress. We have a number of guides that can help;
Cause - Leaking hot or cold water supply, waste water or central heating pipework that can cause anything from gushing water to a slow trickle of damp.
Symptoms - Similar to penetrating damp, but it appears away from the external walls and corners of a room as growing damp patch. Mostly likely to occur on a ceiling or beneath a radiator or sink.
Treatment - Start by fixing the cause of the problem – our handy guide to dealing with plumbing problems offers advice on eight of the most common;
Cause - Rising damp usually occurs in older homes (early 20th century or older). In modern properties, damp-proof courses are built into the footings and foundations of a home. These help to provide a barrier between the moist soil below the house, and the habitable areas above. In older properties however, damp-proof courses may be less substantial or not part of the construction. This means that porous brick walls can absorb moisture from the ground below, allowing damp to rise into the floors above. The addition of modern plaster, insulation, windows and doors in more recent years may also have diminished the building’s ability to breathe, trapping moisture in the walls.
Symptoms – Cold, damp surfaces and mould growth in the external corners of ground-floor rooms. Cold walls and floors, as well as a musty smell, can indicate a potential problem.
Treatment - For homes with substantial rising damp, installing a modern damp-proof course is the best solution. Whilst this can be an expensive option, it will help to prevent any further deterioration of the building and reduce the need for preventative measures in future. Consult an expert to find out the best option for your home and budget. Where symptoms are milder, rising damp can be managed in a similar way to issues caused by condensation.
How to prevent damp and mould
1. Keep on top of outdoor home maintenance
Prevention is better than cure when it comes to damp problems. Check your roof regularly for damage, especially after winter storms. Keep gutters clear and fix or replace as soon as any damage occurs. A specially-designed gutter clearing tool will help to make light work of this, or install gutter guards to help keep leaves and debris out.
Inspect the pointing of exterior brickwork, and if you have any concerns about crumbling mortar speak to a professional to investigate repairs.
2. Keep your home warm
Condensation occurs when warm, moist air touches a cold surface like a chilly window pane or a cold external wall. Loft and wall insulation can help create warmer spaces, and properly fitted double-glazing will help to avoid misty windows as the inner panel of glass is insulated against the cold air outdoors.
Try to maintain a constant temperature within your home by setting your thermostat to a lower temperature, but over a longer period of time each day. This will help to avoid sudden rises and dips in temperature, when condensation could develop. If your central heating system was installed some time ago, consider upgrading elements to make your home more efficient and easier to control. Programmable room thermostats and thermostatic radiator valves (TRVs) make it easier to heat your home where it needs it most, and Smart Home devices enable you to monitor temperature and energy usage as well as control your heating when away from home.
Help to make the most of the heating when it is on by ensuring that radiators aren’t blocked by furniture and that towel warmers aren’t overloaded with damp towels.
3. Ensure your home is well-ventilated
Providing a route for moisture to escape from your home will help to minimise condensation. Double-check that washing machines and tumble dryers are plumbed in and vented correctly. Install an extractor fan in bathrooms and kitchens if one isn’t already in place, and ensure that it is set to run for a long enough period of time to clear moisture from your room.
Open windows when possible – newer window frames may allow you to open windows just a chink and then lock in place. This is especially important during the colder months when we spend more time indoors.
4. Avoid producing lots of moisture
Drying washing indoors can create a lot of condensation, so dry laundry outdoors on a rotary drier or use a tumble dryer whenever possible. You’ll be surprised how quickly laundry can dry outside even in winter (provided it doesn’t rain). Choose an efficient A or A* rated tumble dryer to keep running costs as low as possible. Vented tumble dryers are a good choice if you already have a vent installed, otherwise opt for a condenser dryer that doesn’t need venting and won’t allow moist air to escape into your home. A dehumidifier with laundry setting can be a huge help if drying indoors can’t be avoided.
Try to avoid home improvement and cleaning projects that create a lot of moisture when the weather is cold or wet and surfaces dry more slowly. Tasks such as painting and decorating, mopping floors and cleaning windows are best saved for better days when you can comfortably open a window.
5. Take care when cooking
Pans on the stove, as well as kettles, can produce considerable amounts of steam and moisture. Covering pans with a lid whilst cooking will help to minimise condensation on your kitchen windows. Switch on your cooker hood when using the hob, and leave on for five minutes once you’ve finished to help clear the air. Don’t forget to regularly replace the filter on your cooker hood to make sure that it is working as efficiently as possible.
6. Remove excess moisture
Using a dehumidifier will help to remove excess moisture from the air, leaving your home feeling warmer and more comfortable. Opt for a smart model that switches on when humidity rises, or use a timer to run for a short while every day. You’ll be surprised how much moisture it will remove from your home. Moisture absorbers are ideal for cupboards and tight spaces where damp appears but a power supply isn’t practical. If condensation regularly develops on windows, use a window vac to remove the water in the morning. Alternatively, wipe with a chamois leather and wring out into the sink. This will help rooms to dry out quicker.
7. Choose moisture-resistant décor finishes
If your home is prone to damp or condensation, choose wall finishes that make problem prevention easier. Opt for painted surfaces and choose paints designed for use in kitchens and bathrooms. With formulations designed to resist moisture and steam, they’ll not only help to keep mould at bay, but will also wipe clean more easily should any mould develop. If wallpaper is more your style, choose kitchen or bathroom wallpaper that is able to withstand humidity and can be wiped clean.
8. Leave room to breathe
Condensation can form behind furniture and furnishings that touch colder outer walls, resulting in eventual mould growth. Try to position furniture a few centimetres away from external walls, to allow air to circulate. If you experience a lot of condensation on windows, choosing coverings that can be moved well clear of frames. Fit a generous length of curtain pole or rail that allows you to pull curtains well away from the window, and install blinds over the window alcove rather than within.
How to repair damage caused by damp
1. Damp stains or mould on painted walls and ceilings
Once the source of the damp has been fixed, allow the area to thoroughly dry out using a dehumidifier if needed. Then, treat the surface with a mould removing treatment following the instructions on the packaging carefully. Our customers love HG Mould Remover Spray for this task. Once the surface is free of mould and dry, it can be painted with a damp seal or stain blocker paint which will ensure that the staining does not bleed through the emulsion once completed. Once dry, touch up with the same paint used elsewhere on the wall or ceiling.
2. Mouldy grout and sealant in the bathroom or around sinks
If the grout and sealant is in good condition, begin with a mould removing treatment. Following the instructions on the packaging, remove as much of the mould as possible.
This may be enough to revive the area. However, if it doesn’t fully remove mould stains from silicon sealant, allow the area to dry thoroughly and then cut the old sealant away with a knife blade. Using a mould-resistant sealant and sealant gun, re-seal the affected area and wait until the sealant has cured before allowing the area to get wet.
Many mould removing products contain bleach. Whilst this is very effective at destroying mould, it can damage fabrics and painted surfaces. Wear old clothes, eye protection and a mask when using.