Condensation in homes is caused when the interior atmosphere gets out of balance and is holding too much water vapour and humidity levels remain high (+70%RH) for long periods of time.

An inspection will identify the initial action areas after which further measures may be required

The majority of condensation in homes is created by lifestyle. The level of moisture is the sum of external relative humidity plus the moisture generated within the property which normally buffers the high humidity provided it’s for a short period, but some modern materials (i.e. laminated floors, latex paints), which now make up our home reduce the buildings moisture buffering ability.

Condensation on double glazed window
a UPVC DG Window

The most common wall/ceilings affected by black mould due to condensation are typically your bathroom, kitchen and bedroom walls are often susceptible to black mould growth. Wet surfaces and steam from the shower can cause condensation to form if the bathroom is not ventilated and move to other areas etc.

Brief Action plan

Balanced heating and ventilation at water vapour production points will lower the level of moisture in your home.

The young, elderly or anyone with a compromised immune system, should avoid areas affected by mould growth or dampness. It is not a good idea to sleep in any room affected by mould growth unless the area has been properly cleaned.

Maintain the ambient temperature above 15oC and ideally between 18-21oC,  avoid heating the property for short periods as this will reduce its moisture buffering ability.    

When showering or bathing keep the door shut and the area heated and ventilated until it dry.

Avoid drying clothes within the building, if you have to, keep them in one room, which is heated and ventilated.  A dehumidifier may be of help if you are unable to ventilate. Check that you have the correct type of extractor fan in the bathroom and kitchen/utility room, ideally, it should have a continues run setting (or humidity control sensor (set at <60%RH). If you have no mechanical ventilation then a damp control ventilation fan must be installed. Note: It is very important as most of the extractor fans we find during inspection doesn’t work correctly and or are the wrong type of fan.

Open window trickle vents were fitted, but not in the room with an extractor fan to control moisture is installed as this will compromise extractor fan ability to remove moisture.

Repair any defects which allowing water to penetrate the building fabric or any plumbing leaks.

Clean and dry any mould affected surface (which is less than  1m2) immediately.  Larger affected areas may need professional cleaning.  Use an anti-mould emulsion paint may be of help in sever situations.

 Wash all affected clothing in a >50˚C wash to control mould (check labels for suitability).

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