Q. THERE is mould growing on the walls and on my items in the house which I rent, my agent had a look and told me that this is not mould but condensation and I am therefore responsible for it and any damage caused to the house as a result.

I am confused; I was under the impression that landlords are responsible for damp.

Mrs D, Stroud

A. When the moisture content in the air inside a building is too high it condenses causing mildew on cold surfaces, especially on the coldest walls, typically on north walls, around windows, behind furniture and in wardrobes where there is less air circulation, but can also form on furniture or even as on fabrics.

This then causes mould to grow, particularly if there has been a previous issue leaving mould spores behind, and looks like black/green specks collected in clusters.

This issue is particularly attributed to properties with solid walls or with very low levels of natural ventilation.

This high level of humidity in the air and mould spores are not particularly healthy, they can aggravate eczema, respiratory issues especially in those already susceptible to them making it a contentious issue in rental properties.

The landlord is responsible for the fabric in the building, its structure and maintenance, and as you said for damp if it is in fact damp coming into the building.

First and foremost landlords need to ascertain what the cause of the mould is and where the moisture is coming from.

Check that this is not rising or penetrating damp, that the roof and gutters are sound and clear, and that the walls and plumbing are all sound.

Assuming that these things are all fine and this is a condensation issue, it may be being worsened by the lack of proper damp coursing and insulation; there are grants available for insulation.

Landlords must also provide adequate ventilation, particularly in bathrooms and kitchens, and adequate heating.

Last but not least educate your tenants on how to best deal with this issue.

Tenants are responsible for the moisture produced by them within the property and any subsequent damage, being the only person/people who can control the levels of moisture and ventilation.

Firstly minimise the amount of moisture caused in the property by keeping lids on pans when cooking, turn off the kettle as soon as it starts boiling, dry clothes outside or in a well ventilated bathroom with the door shut (an average load of washing creates approximately nine pints of water) and make sure that tumble drier extraction pipes are letting the moisture out of the building and not leaking into the house.

Do not use portable gas or paraffin heaters; these produce a high level of moisture.

Clean off the mildew build up on the windows rather than allowing it to evaporate back into the air and re-condensate.

Most of all ventilate.

After baths/showers keep the window open or extractor vent on for an hour, the short time it takes to turn off after the light is switched off is not sufficient.

Always keep the extractor fans on and the doors closed in kitchens and bathrooms when creating moisture to avoid it spreading through the house.

Keep the trickle vents in the windows open at all times and open windows regularly.

You may think it costs more to heat the house when letting cold air in by ventilating, but in actual fact, it is easier and therefore cheaper to heat drier air than air which is heavy with moisture.

If the above is not sufficient consider using a dehumidifier they are surprisingly cheap to run.

Keep the house well heated, maintain a low level of heat, 10 degrees C minimum, at all times by turning your thermostat heating control down during the day and back up to 16 or 18 degrees C when you are at home rather than turning the heating on and off and allowing the house to get very cold during the day causing the moisture to condensate.

To remove mould use a fungicide with a Health and Safety Executive approval number, or mild bleach solution making sure that the room is well ventilated at the time, always test a small patch first.

You may need to repeat this several times, once the cause has been eradicated paint with a mould resistant paint to stop the issue re-accruing.

Please continue to send in your letting related questions to rose@sawyersestateagents.co.uk