Condensation season is generally between October and March and although we are coming towards the latter half of the season, now would be a good time to act and be ready for next year.

Condensation is a widespread problem and it is normal in the colder months to close windows and shut air vents (if any). In winter, we may also be spending more time at home and creating more moisture than usual from drying clothes indoors for example. The warm air from central heating will hold more water vapour than cold air but when the heating is turned off and the temperature drops, the humidity levels will rise and when it comes into contact with cold surfaces and the dew point is reached, condensation will occur as the excess moisture is released.

With the increase in fuel costs, government incentives and our subsequent desire to save fuel and money we are insulating our homes more than ever before. We are now creating air tight boxes as we install windows with rubber seals to keep draughts out, seal up chimney flues, close off air vents, install thicker insulation in our lofts and insulate the cavity walls. This can sometimes cause more harm than good particularly if you fail to provide adequate background ventilation to allow fresh, dryer air into our properties and thus remove stale damp air.

Condensation around window frames etc is normal and of no real concern but when it starts to cause mould growth on walls and furniture and subsequently damages the building fabric this can become distressing to owners and occupiers.

Condensation is usually attributed to lifestyle. It is estimated that a family of four can produce up to 14 litres of water a day.

Small and simple changes can make a huge difference; keeping bathroom and kitchen doors closed, drying clothes in well ventilated rooms with doors shut will all help. Installing kitchen and bathroom fans and providing some background passive ventilation can make dramatic improvements.

Condensation is often misdiagnosed as rising damp and I would always recommend a thorough survey by someone who will take the time to assess the problem. I will normally take 2-3 hours on site and if you are a landlord, I will talk to your tenant about their lifestyle with regards to the amount of moisture they are creating and what precautions they are taking to reduce airborne moisture. The survey will include an assessment of your current ventilation system, if any, and the amount of insulation that your property currently has. Damp meters and hygrometers (to check relative humidity) will also be used where required.

Following the inspection, I will then formulate a written report which will discuss the current problem and what precautions you or your tenant can take to reduce condensation. If you have no mechanical extraction in wet rooms or passive ventilation in your property, then advice will be given and, if you require it, a quotation for improvements to be carried out by us.

There are many manufacturers of passive and mechanical extraction available but I would always recommend using good quality systems that may cost more than the type you may pick up from your local DIY outlet but they will last longer and perform much better.

A few examples of what we regularly fit are discussed below:

Positive Pressure Ventilation systems

This type of system is becoming very popular for Landlords and Home owners.

The positive pressure system is a unit which fits into the roof space and has a diffuser (input) panel fitted in the landing ceiling. Fresh dry air at ambient temperature is introduced into the property – diluting and displacing stale moist air and reducing condensation. There are two models, a standard model and one with a pre heat facility. This pre heat will automatically engage when the temperature falls below 10˚c. There is also a flat system for situations were no roof void exists. This will fit on an outside wall and by the use of ducting, push the air into a central hallway.

Humidistat extractor fans

Humidistat fans take the onus away from you or your tenant to regulate how long the fans should stay on for. Under the control of a microprocessor, the sensor monitors continuously the relative humidity (RH) in the room. If there is a sudden rise in the RH, the sensor anticipates hitting the set point and activates the fan before it is reached. After the fan has reduced the RH to about 5% below the preset set point, the fan switches off.

Passive air vents

If you are dragging moisture laden air out of your property by the use of mechanical fans, you need to balance this with an intake of fresh dryer air. This function will be carried out by passive air vents such as air bricks or trickle vents in windows. Again a good quality air brick with an anti-draught baffle is an important factor to consider.

To arrange a survey please call or email and I will be happy to discuss your requirements and the cost of the survey with you.