How Closed-Cell Spray Foam Impacts Indoor Air Quality

When it comes to home insulation, closed-cell spray foam was an effective solutions. It provides exceptional thermal resistance, moisture control, and structural reinforcement. However, many homeowners overlook its potential impact on indoor air quality (IAQ). While closed-cell spray foam has clear benefits, poor installation, ageing foam, or the need for removal can all influence the air you breathe.

At Countrywide Roofing and Insulation, we don't just install spray foam—we also specialise in open-cell and closed-cell spray foam removal, ensuring your property stays safe, breathable, and compliant with UK building regulations.

1. How Closed-Cell Spray Foam Affects Indoor Air Quality

Off-Gassing and Chemical Emissions

Freshly applied spray foam releases volatile organic compounds (VOCs), which can cause headaches, respiratory irritation, and allergic reactions. While these emissions typically subside within a few days, low-quality materials or poor installation can prolong the problem, affecting indoor air for weeks or even months.

According to the UK Health and Safety Executive (HSE), exposure to isocyanates—chemicals used in spray foam—accounts for 17% of work-related asthma cases in the UK.

Restricted Ventilation and Airflow Issues

Closed-cell spray foam is excellent for sealing gaps, but an airtight home without proper ventilation can trap pollutants and excess moisture. This can lead to:

• Condensation and Mould Growth – Particularly in lofts and crawl spaces.
• Accumulation of Indoor Pollutants – Including carbon dioxide, allergens, and residual chemicals.

If your home lacks adequate airflow, spray foam removal or modification may be necessary to restore proper ventilation.

Foam Ageing and Degradation

Over time, closed-cell spray foam can deteriorate, especially in humid or extreme conditions. Degrading foam can release airborne particles, which, when inhaled, may pose respiratory risks.

Research indicates that indoor air pollution can be up to five times worse than outdoor air, primarily due to poor ventilation and trapped contaminants.

2. Signs That Spray Foam Removal May Be Necessary

While closed-cell spray foam is built to last, there are instances where removal is the best option:

✅ Foam Cracking or Deterioration – Old or poorly applied foam can release airborne debris.
✅ Lingering Chemical Smell – Persistent odours suggest off-gassing issues.
✅ Mortgage and Survey Compliance – Some lenders require removal for property financing.
✅ Moisture and Mould Problems – Insulation can sometimes mask underlying dampness.

At Countrywide Roofing and Insulation, we specialise in safe and efficient spray foam removal, ensuring your home meets UK regulations and remains safe to live in.

3. A Simple Analogy: The 'Sealed Bottle' Effect

Imagine your home as a sealed water bottle. While it's great at keeping things inside, it also traps everything—good and bad. Closed-cell spray foam locks in warmth but can also trap pollutants, chemicals, and excess moisture.

Just like stale water in a sealed bottle can develop an unpleasant taste over time, stale indoor air in a poorly ventilated home can become polluted. Without proper airflow, indoor air quality suffers, which is why periodic insulation assessments—and sometimes removal—are essential.

4. FAQs About Closed-Cell Spray Foam and Air Quality

Q1: Is closed-cell spray foam toxic once it has cured?

Once fully cured, high-quality closed-cell spray foam is generally safe. However, if applied incorrectly, it can continue off-gassing for an extended period, affecting air quality. That's why it's important to hire experienced professionals for both installation and spray foam removal if needed.

Q2: How can I tell if my spray foam insulation is affecting my home's air quality?

Look out for these signs:

• Persistent chemical odours that don't fade over time.
• Increased allergy symptoms or breathing issues in occupants.
• Condensation, damp smells, or mould growth—especially in lofts, attics, and basements.

Q3: Can spray foam insulation be safely removed?

Yes! At Countrywide Roofing and Insulation, we use specialist techniques to safely remove both open-cell and closed-cell spray foam while minimising disruption to your home.

Q4: Will removing spray foam improve my indoor air quality?

If your spray foam insulation is off-gassing, trapping pollutants, or causing ventilation issues, removing it can significantly improve indoor air quality. A professional assessment can confirm whether removal is the best option.

Q5: How do I get started with spray foam removal?

Simply contact Countrywide Roofing and Insulation for a free consultation. We'll inspect your insulation and recommend the best solution based on your home's needs.

Conclusion: Prioritise Indoor Air Quality with Expert Spray Foam Removal 

While closed-cell spray foam insulation is a fantastic solution for energy efficiency, it's important to recognise its potential impact on indoor air quality. Issues like off-gassing, moisture retention, and ventilation restriction can compromise the health and comfort of your home.

At Countrywide Roofing and Insulation, we offer expert spray foam removal services to ensure your home remains safe, breathable, and compliant with UK regulations. Whether you need removal due to air quality concerns, mortgage requirements, or insulation degradation, our team is here to help.

📞 Get in touch with us today for a free assessment and expert advice!