DAMP may sound like a dry subject but if you're not careful it can do serious damage to your home.

Steamed up windows and dark patches on the wall are obvious signs that something needs to be done but often householders are unaware of deterioration until it is too late.

Mike Parrett - dubbed the Damp Doctor since a BBC2 TV programme exposing damp myths - says home owners could save themselves thousands of pounds in repair bills if only they took preventative steps first.

A trained surveyor and now author, Mike said: "Dampness can be all pervading in a property, making it a miserable place to live and a nightmare to maintain, but it can be eradicated if people take the right action."

He has been drafted in as one of the experts for National Maintenance Week, which starts this Friday, and is organised by SPAB, the Society For the Protection of Ancient Buildings to annually urge people to check over their homes before winter sets in.

If you have damp patches on your wall you should grab an umbrella and go and check the guttering and behind the downspout to see if either are blocked and leaking.

If the damp is lower down on ground floor walls check whether the outside ground levels are higher than the inner floor. They should be two bricks lower than the damp course and if they aren't will need digging out.


At the same time, check the airbricks have not been blocked up. If your house has suspended timber floors make sure there is no rubbish and rubble underneath affecting ventilation, and if you live in a Victorian terrace and are finding damp in the hallway, it could be a leaking water main. They often run along the hall to the kitchen, so get your water supplier to run a pressure test.

If your house pre-dates WWII it is likely to have lime mortar, which is a breathable material, but if this has been rendered over it will have trapped moisture into the walls. Similarly, if the rendering reaches below the damp proof course it will be breached, allowing moisture to travel and should be removed.

Any damp around a chimney breast is likely to be rainwater, so capping the chimney is the solution. If the damp is on a party wall with your neighbours then you need to get them to make the same checks to eliminate obvious problems.

But if you have done all the checks and still the walls are damp you may need to call out a specialist but get several opinions and quotes for the remedy before going ahead with the work. Don't rely on damp meters prodded into walls to be a 100 per cent accurate indicator of damp levels as they can be affected by foil-backed paper or carbon levels in the walls.


But according to Patten if there is no physical fault causing damp then it is often householders own actions that are to blame by creating steamy kitchens and bathrooms which lead to condensation.

He said: "Condensation forms when warm moisture-filled air hits a cooler surface, like a single glazed window or an outside wall. It is a major factor in causing damp but can often be solved simply by changing your behaviour.

"Liquid based heating is a particular culprit, with a Calor Gas heater producing one gallon of water for every gallon of fuel and unvented driers are not far behind.

"All the moisture they pump out has to go somewhere and very often where it goes is into your walls and your window frames, causing long-term damage."

In the summer the usual answer is to open a window and the damp air will be drawn outside, but in winter the air outside is often damp too, so opening a window will just exacerbate the problem.

So how do you de-steam your rooms if it is foggy outside and you've children to bath?


Patten said: "Opening your window some days is futile. You should endeavour not to create too much condensation and steam by always closing your kitchen door while cooking, venting your dryer to outside, not drying clothes on the radiator or maiden, and fitting an extractor fan in the kitchen and bathroom.

"But if you know there will be occasions when it happens, then a de-humidifier will get rid of the gallons of water that would otherwise seep into the fabric of your house.

"If you live in a modern property with double glazing and efficient central heating it is incredibly important that you allow some ventilation to allow air to flow through the house.

"And ideally you should try to keep your home at a consistent temperature. Letting the heating switch off at 11pm and then back on in the morning will cause condensation during the winter and while I realise there are cost implications you should try controlling the temperature through the thermostat rather than the time clock to see if that helps."