Barbara Roberts, cleaning expert at Merry Maids has the following advice for wooden windows that have developed mildew as a result of condensation:

Barbara says prevention is better than cure and to prevent mildew, you must prevent condensation building up on windows by ensuring there is sufficient ventilation in the room.

However, if you do come across a build up of mildew stains, Barbara recommends rubbing a dry, mildly abrasive sponge over the affected area to loosen some of the black mildew. Wipe off with a paper towel and discard.

Barbara advises following this by fully washing down the area with warm soapy water and a sponge. Finally, the mildew needs to be treated with bleach. Put on rubber gloves and in a bucket, mix 240mls of household bleach with four litres of water. Dip a soft sponge in this solution, squeeze excess fluid out of the sponge and wipe down the mildew-stained wood and then scrub heavily stained areas. Rinse out the sponge frequently. Allow the solution to sit on the stain for a few minutes to kill the mildew. Wipe the area well with paper towels to dry the wood as much as possible. If you have a fan heater direct towards the window to aid drying.

For more information or specific advice visit www.merrymaids.co.uk or call 0800 021 3072.