Mould usually returns because the moisture conditions supporting its growth are still present. Possible causes include condensation, high indoor humidity, restricted ventilation, water ingress, plumbing leaks, cold surfaces or missing insulation. Cleaning removes the visible mould but will not prevent it returning if the moisture source remains.

The colour of mould alone does not identify its species or determine the level of health risk. However, persistent mould indicates an unresolved moisture problem and should not be ignored. Damp and mould can affect indoor air and may have a greater impact on children, older people and those with respiratory conditions or weakened immune systems. Anyone concerned about symptoms should seek medical advice.

Yes. Persistent moisture can damage paint, wallpaper, plaster, insulation, metal fixings and timber. It may also create conditions in which mould or timber decay can develop. The extent of the damage depends on the moisture source, how long it has been present and the materials affected.

Damp, mould or unexpected moisture readings may be raised during a property survey and can concern prospective buyers. Establishing the likely cause, completing appropriate repairs and keeping inspection and repair records can help explain how the issue has been addressed. This does not guarantee that it will not be mentioned in a future survey.

A damp patch should not be painted over until its moisture source has been identified and addressed. The affected area should also be allowed to dry sufficiently before damaged plaster or decoration is repaired. Painting too soon may temporarily hide the mark, but staining, bubbling or peeling can return.

A dehumidifier can reduce moisture in the air and may help manage condensation temporarily. However, it may not correct the reason humidity is building up. Heating patterns, extractor fans, background ventilation, insulation and cold surfaces should also be considered before deciding on a long-term solution.

Damp is a broad term for unwanted moisture within a property. Condensation is one possible cause and forms when moisture in the air meets a colder surface and turns into water droplets. Other damp problems may be caused by rainwater penetration, plumbing leaks, ground moisture or materials bridging a damp-proof course.

Thermal bridging occurs where part of a wall, ceiling or roof loses heat faster than the surrounding structure. This creates a colder internal surface where condensation and mould may repeatedly develop. It can be associated with missing, compressed or displaced insulation and certain construction junctions.

Consider arranging an inspection when damp patches or mould keep returning, the problem is becoming worse, damage changes with rainfall, timber feels soft or the cause is unclear. An inspection may also be helpful when a property survey reports unexpected moisture readings and further investigation is recommended.