With damp a common problem in UK homes, we’ve identified the major causes and found out how to get rid of damp and condensation, and stop mould from building up
As the weather turns and winter sets in, you might be greeted by some unwelcome house visitors. No, not trick or treaters or door-to-door salespeople. We’re talking damp.
Damp doesn’t discriminate. It can occur in any home, from a studio flat to a sprawling mansion. Often caused by failing to keep up with house maintenance, it can prove a real headache. Clothes and furniture can be damaged and it can also trigger health problems like asthma. That’s why, if you do see signs of damp, it’s best to get to the bottom of the problem as soon as possible.
Clear the air: Keep your home healthy by cutting down on allergens
What causes damp?
In is simplest form, damp is caused by condensation. As the temperature falls, condensation rises, creating moisture on windows each morning which will eventually cause mould and damp.
But that’s no the only cause of damp. Leaking pipes, wastes or overflows might be the culprits. Rising damp that comes up from the ground is commonly caused by having a damaged damp-proof course, or no damp-proof course at all. Or there could be water penetrating from outside because of a missing roof tile, leaking window frame or blocked gutter.
What kind of damp do I have?
Luckily damp is easy to identify. Start by sourcing the cause. For example, a damp patch on the wall at the top of a chimney breast suggests a leak from the chimney stack, a wet patch at the top of a wall may indicate a leaking gutter and damp near windows might mean a damaged drip groove beneath the window sill.
Condensation, the most common form of damp, is often caused by poor heating and ventilation. It occurs when activities such as cooking raise the level of humidity in a building. This air condenses on cold surfaces, such as windows and walls.
Running water on windows is the most obvious signal of condensation and can lead to stained curtains, decaying window frames or moulding on paint and wallpaper.
Rising damp is water that enters a structure from the ground. Symptoms include decayed skirting boards and floors, stained plaster, and peeling paint and wallpaper.
Penetrating damp is when water enters a building from outside and moves through the walls, often creating stains or mould growth at some distance from the leak. Caused are defects in guttering and pipes, faulty flashings, poor pointing and cracked rendering.
How to get rid of condensation
‘Just turning up the heating in the winter will not get rid of condensation,’ advises Chris Michael from dehumidifier supplier Meaco. ‘A damp property means damp air, and raising the heating thermostat will only heat up the wet air molecules, rather than raise the room temperature.’
That said, there are some quick and simple remedies for banishing damp.
1. Wipe down windows and sills every morning
Image credit: Debi Treloar
Remove the condensation as soon as you see it as this will stop any mould from building up. Use kitchen towel, a squeegee or a window vac – we like Vileda’s Windowmatic, which costs around £20. It might help to occasionally wipe down walls and window frames with a fungicidal wash.
Buy now: Fungicidal spray 500ml, £3.50, Wilko
If you’re removing mould caused by condensation, the NHS recommends that you wipe it away with a cloth dipped in soapy water. When you’re done, use a dry cloth to remove any moisture, and throw both cloths away. It advises to ‘Be careful not to brush the mould, as this can release mould spores’.
2. Deal with steam from cooking
Always cover pans and pots when cooking. This won’t just prevent steam escaping, but also saves energy. You could also close the kitchen door when cooking to stop steam escaping to other parts of the house.
Improving your heating and ventilation systems will do a long way to solving condensation issues. Install extractor fans in kitchens and bathrooms to reduce moisture. You can pick up powerful cooker hoods for less than £200, so this can be an extremely cost-effective long-term solution.
Ventilating your home can be as easy as opening a window for at least 15 minutes each morning. If you have windows that can be locked in a slightly open position, all the better.
‘Opening the window to bring in fresh air will work fine if you are heating the room up,’ explains Chris Michael. ‘Because by increasing the air temperature you will decrease the relative humidity of that air.
If you have bad condensation issues in a particular room, consider fitting air bricks. These are bricks with lots of tiny holes in them, and can be added to exterior walls, allowing air to pass under a suspended timber floor. Traditionally made from clay, they are now more commonly made of plastic. Plastic bricks allow for better airflow and are less easily broken. Long term, they will prevent damp and moisture from damaging the floorboards.
Good insulation is just as important as decent ventilation, especially if you have cold spots on walls where condensation builds up. Cavity wall, loft and other specialist insulation can combat damp – though in rare cases it can also cause it, so always consult with an expert before you start your project. You should also consider replacing draughty old door and windows with double or triple glazing.
5. Buy a dehumidifier
Contents in a home left empty for long periods can easily be damaged if they absorb and hold excess moisture from the air. The same applies to properties that feel permanently damp, due to their location, (perhaps built against the side of a hill) or age.
This is where a dehumidifier comes in. It will reduce the level of humidity in the air, by sucking in air from the room at one end, removing the moisture, and then blowing it back out into the room again, adding warmth in the process.
If you’re looking for a reliable model, we like the multi award-winning Zambezi dehumidifier from Meaco. You can set it on a timer to run daily at specific times, and it’s clever enough to know if it’s on the wrong extraction setting. If it is, it will adjust itself to create the right conditions. It also works well in colder conditions, so you could use it in a garage or shed.
How to get rid of penetrating damp
You may need to repair or replace your gutters. It might be your window sill dip grooves – designed to shed rainwater so it doesn’t run down the house wall – are blocked and need to be reformed.
How to get rid of rising damp
Serious damp problems may require that you consult a qualified surveyor. They will take a moisture reading at your home, identify the cause of the problem and advise you on the right course of action.
Find a professional in your area at The Property Care Association scheme.
It may be that the problem is easily remedied, but your surveyor could recommend installing a new damp-proof course, which can costs £1,000s. This involves injecting the walls with chemicals that will form a water-repellant barrier. This can be done from the outside of the building, or your specialist may need to strip the interior wall back to the brick to inject the course. They will them recover them with a specialist plaster.