Debunking the biggest myths about damp, mould and ventilation

For decades, damp and mould have been surrounded by confusion, half-truths and well-meaning but inaccurate advice. In the housing sector, these myths often slow down effective action, place unfair blame on tenants and create unnecessary maintenance costs. 

Here we break down the most common misconceptions — and explain what really causes mould, what doesn’t, and what modern solutions look like. 

Myth 1: “Opening windows fixes it.”

Many people believe that cracking open a window quickly “clears the moisture” and therefore prevents mould. Unfortunately, that’s not how mould works. 

Why it’s wrong: 

• Ventilation can reduce moisture and help improve conditions to stop mould from appearing. It does not remove existing mould spores. 

• Spores continue to settle in carpets, fabrics, furniture and porous materials — where opening a window or installing a ventilation system has little impact. 

• In colder months, this advice is neither practical nor energy-efficient. 

What’s true: 

• Windows help with airflow. They don't eliminate mould, and they don’t deal with the underlying spores circulating in the property. 

What modern solutions do: 

Effective mould control requires continuous elimination of airborne and surface spores — something ArcAirTech specialises in through patented, nature-based technology. 

Myth 2: “Mould only appears in old properties.”

It’s easy to assume that mould is a symptom of ageing homes — draughty walls, old roofs and outdated construction. 

Why it’s wrong: 

• New-build properties can have higher humidity levels, especially in the first 12–18 months as materials dry out (and in a damp climate, this can take even longer). 

• Airtight, highly insulated construction improves energy efficiency but can allow a property 

• Systems like PIV and MVHR can help stabilise indoor conditions and reduce the likelihood of mould colonies forming, but their performance is dependent on correct operation and consistent maintenance. 

• Mould thrives anywhere moisture and still air combine — old or new. 

What’s true: 

Mould is one of the most robust micro organisms ever identified, it has the capability to grow, germinate, proliferate even in the harshest of environments. It is a ventilation, humidity and spore problem, not an age problem. 

Myth 3: “It’s always the tenant’s fault.”

This is one of the most damaging and persistent myths in the housing sector. 

Why it’s wrong: 

• Tenants can influence moisture levels, but they cannot control structural conditions like insulation, thermal bridging, defective ventilation or cold surfaces. 

• Tenants cannot see or address mould spores in the air, in carpets, behind furniture or in voids. 

• Blaming tenants creates distrust and delays genuine solutions. We are also living in a time where new legislation reinforces landlord responsibility for environmental conditions. 

What’s true: 

A property with mould has an environmental problem, not a behavioural one. Housing providers now look at: 

• humidity 

• heat retention 

• airflow 

• spore load in the home 

This shift is aligned with Awaab’s Law and the Renters’ Rights Bill, both driving higher standards of tenant health and property safety. 

Myth 4: “More heating solves everything.”

Heating helps reduce visible condensation — but again it cannot eliminate mould spores. 

Why it’s wrong: 

• Warm air holds more moisture, meaning humidity can stay high even when the property is heated. 

• Heating doesn’t reach mould spores in fabrics, furnishings or hidden areas. 

• Many tenants cannot afford sustained heating throughout winter. 

• A warm, poorly ventilated property can still have a mould problem. 

What’s true: 

Heating helps comfort and condensation control, but it is not a mould treatment. 

So what does work?

Eliminating Mould Requires Tackling Spores, Not Just Moisture! Here’s the crucial truth: Mould is a spore issue, not just a damp issue. 

Traditional Approaches vs. What They Actually Solve 

ArcAirTech: A modern, evidence-based approach

ArcAirTech’s patented, nature-based technology: 

• Eliminates airborne and surface mould spores 

• Reaches areas traditional methods cannot 

• Works while tenants remain safely in the home 

• Supports landlords in meeting legislative requirements 

• Reduces long-term mould recurrence 

It doesn’t rely on tenant behaviour, daily routines or perfect ventilation — it deals with the environmental cause at its root. Modern housing strategies require modern solutions — ones that remove spores, work in real-world conditions and support both landlords and tenants in maintaining healthier homes.  

Over the last several years, ArcAirTech has worked closely with housing associations, private landlords and local authorities to validate our approach in real homes — not just laboratories. With proven results across more than 40 housing providers, we’ve demonstrated that eliminating mould spores dramatically reduces repeat issues, cuts ongoing maintenance costs and supports compliance with modern housing standards. Our technology is trusted because it works, it scales and it allows tenants to remain safely in their homes.  

As legislation tightens and expectations rise, ArcAirTech continues to help landlords adopt a practical, evidence-driven approach to creating healthier, mould-free homes at scale.