How to deal with damp

Damp can be a common problem in older houses and can be incredibly costly to fix. So how can you can prevent it and what should you do if your home is affected?

As well as looking unsightly, damp and mould can cause serious issues. Not only can it leave you with an unpleasant musty smell lingering in the atmosphere, it can also harm the structure of your property and even cause health problems such as asthma and allergies.

It’s imperative to treat damp as soon as possible because once it’s taken hold it can be difficult – not to mention expensive – to get rid of. Protecting your home from damp will keep it safe for years to come.

If you spot signs of damp and mould, it’s important to identify which type it is before you try to fix it.

There are three main types of damp:
 

Rising damp is mostly found in old properties, particularly those pre-dating 1875 when houses weren’t built with protective damp-proof courses. It only occurs in basements and at ground floor level as it’s caused by moisture from soil moving up through a wall or floor. This type of damp can be easy to misdiagnose, so it’s advisable to get expert advice if you think you have it.

Signs of rising damp include:

• Decaying skirting boards
• Crumbling plaster
• Tide marks on walls

Penetrating damp is caused by rain getting into a property through walls and ceilings. This could be due to a leaking roof, blocked gutter or burst pipe. You’re more likely to experience penetrating damp if you live in an older building with solid walls rather than cavity walls, which provide some protection.

Signs of penetrating damp include:

• Large damp patches on walls
• Decaying timber
• Watermarks on masonry particularly after heavy rain

Condensation is the most common type of damp, with one in five UK homes affected. It’s caused by moist warm air coming into contact with a cold surface, typically in kitchens and bathrooms.

Signs of condensation include:

• An unpleasant musty smell
• Water droplets collecting on windows
• Unsightly black mould
• Peeling paint or plaster

Where damp is concerned, prevention is most definitely better than cure. These tips can help you protect your home:
 

A hot and stuffy home can result in a build-up of excess moisture, causing mould and mildew, so it’s important to let the air circulate around your property. It’s a good idea to open a window every day, even if it’s cold outside. If you have air vents in your kitchen and bathroom that lead outside, make sure nothing is blocking them. And don’t lie furniture flat against walls as air won’t be able to circulate behind it.

Everyday activities like showering and cooking can increase humidity inside your home and cause condensation. To reduce the amount of moisture:

• Use an extractor fan when cooking and keep lids on saucepans
• Only boil the kettle when you need to
• Dry your washing outdoors whenever possible
• Open windows and leave internal doors open
• Wipe down the bath, shower and tiles after every use

Another way to reduce the amount of condensation in your home is to keep it well heated. Since condensation is created when cold and warm moist air clash, a cold room is more likely to become damp, especially during the winter months. Loft and wall insulation can help reduce heat loss, while well-fitted double glazing will help to avoid steamy windows.
 

Check your roof regularly for damage, especially after a winter storm, but don’t attempt to fix a leak yourself if you’re not a professional. Keep gutters clear of leaves and debris to avoid rainwater streaming down the side of your property as it will eventually seep inside.

Water can get in through the walls as well as the roof, so inspect the pointing of exterior brickwork and masonry for cracks or potential weak spots.

If damp-proof courses and air bricks are covered up by outside paths, rendering, or garden borders, the damp-proofing can become bridged, making it ineffective and allowing moisture to penetrate a wall.

If you have damp or mould in your home, the first step is to identify the source of it and get it fixed.

Dry out the damp area thoroughly – this may involve using a dehumidifier. In many cases, if the damp is caused by condensation and covers an area of less than 1x1 metre, you should be able to treat the affected area yourself with a mould removing treatment.

To protect yourself from mould spores, it’s advisable to wear goggles, rubber gloves and a mask over your nose and mouth. Open windows but keep doors closed so spores won’t spread to other parts of the house.

Once the affected surface is dry and mould-free, you can paint it with a damp seal or stain block paint.

If you have old or cracked grouting in your kitchen or bathroom that is causing damp and mould, you can rectify the problem by re-grouting your tiles.

Rising damp is less easy to fix, so to deal with this you’ll probably need help from a professional. Treatment involves either a damp-proof course or new damp-proof membrane.

The worse a damp situation gets, the more it’s likely to cost to repair any damage. Most standard buildings and contents home insurance policies do not cover damage caused by damp and condensation.

A damp-proof course can run into thousands of pounds if the whole house needs treating. Each case is different, but a rough estimate is around £300-£600 per wall depending on the size of your property.

Make sure you really need a damp-proof course damp proof treatment before you pay out for it as damp is often misdiagnosed. If needs be, seek advice from an independent damp specialist or an independent and qualified Chartered Surveyor from the RICS to find out whether the treatment is absolutely necessary. They will charge a fee but will be more likely to accurately diagnose the problem, potentially saving you money in the long run.