It’s Not Going Away: Why Damp and Mould Still Exist In Our Homes

The current state of our housing stock

Our homes have been built and adapted over generations. Many were constructed before modern expectations for insulation and energy performance, leaving housing providers working to improve buildings that were designed for different conditions.

Age alone does not determine whether a home becomes damp. Its construction, condition and previous alterations all matter. Deteriorating roofs and leaking gutters can allow water into the building, while poorly insulated walls can create cold internal surfaces where moisture accumulates.

Later improvements also need careful consideration. Replacing draughty windows or increasing airtightness can improve comfort, but adequate ventilation must be maintained so that moisture can escape. Heating, insulation and ventilation need to be considered together.

For much of our existing housing, we are playing catch up. Addressing  this requires planned investment, regular maintenance and improvements suited to each building’s construction.

Getting the diagnosis right

Visible mould tells us there is a problem but does not establish its cause. Moisture may come from leaking pipes, rain penetrating the building or condensation on cold surfaces. Several factors can be present at once, so identifying condensation still leaves a further question: why is moisture accumulating in this particular home?

A thorough assessment should examine the building inside and out, including its roof, rainwater drainage, plumbing, heating and ventilation. Previous repairs and alterations should be reviewed, with appropriate measurements interpreted by someone who understands the building’s construction and how moisture moves through it. A single damp meter reading cannot establish the cause.

Residents’ accounts are part of that evidence. When did the problem begin? Does it worsen after rain or affect particular rooms? Are there difficulties keeping the home warm or using its ventilation? These conversations can reveal details that a short visit misses. Everyday activities such as cooking and bathing produce moisture, and homes need to accommodate them.

Immediate action to protect residents should accompany the investigation. Removing visible mould needs to be followed by work that addresses the conditions allowing it to return.

Adapting to a changing climate

Changing weather adds to the challenge. The Met Office projects warmer, wetter UK winters on average, with heavy rainfall also becoming more likely. Wetter conditions can put additional pressure on roofs, walls and drainage, exposing defects that allow water to enter.

The effect within each home depends on its construction and exposure, alongside indoor temperatures and ventilation. We need to understand how individual buildings respond to changing conditions.

This strengthens the case for including climate resilience in maintenance and investment plans. Keeping gutters and drains clear, repairing defects promptly and checking exposed parts of a building after severe weather should sit alongside improvements to its energy performance. Retrofit plans also need to account for moisture movement and ventilation.

Making measurement central to prevention

Without reliable measurement, effective management is difficult. A reading taken during one visit captures that moment, while temperature and moisture conditions change throughout the day and across seasons.

Continuous monitoring of temperature and relative humidity can help reveal persistent patterns that occasional visits miss. It can show whether conditions associated with mould risk are sustained or recurring, helping housing teams decide where further investigation is needed.

Interpretation is essential. Relative humidity changes with temperature, and readings describe environmental conditions rather than directly detecting mould or proving its cause. Good sensor placement and reliable records help make the information useful. It should be assessed alongside inspection findings, repair histories and residents’ experiences.

Bringing this evidence together can help housing providers prioritise preventative work and identify recurring issues across similar properties. Monitoring after repairs, supported by follow-up inspections and resident feedback, can also help establish whether improvements have lasted. Seasonal and weather changes need to be considered when comparing results.

For data to improve homes, there must be a clear route from identifying a concern to investigating and resolving it. Teams need to know who reviews the information, who responds and how progress is checked. Gathering further readings should never delay action on reported damp and mould.

Damp and Mould Action and Awareness Week is an opportunity to review that process. A case should be judged by sustained improvement in the home and the resident’s experience, with the findings used to prevent the same problem developing elsewhere.

By Freddie Hudson, Marketing Executive, Aico

Image credit: Aico