Spray Foam Insulation Problems Explained

🚫 Spray Foam Insulation Problems: The Hidden Threat to Your Roof

Published by Advanced Roofing Specialists – Serving Norfolk & Suffolk

Introduction

Over the past decade, spray foam insulation has been aggressively marketed to UK homeowners as a modern, energy-saving solution. Promises of warmer lofts, reduced heating bills, and long-term efficiency gains have persuaded many households to invest.

However, at Advanced Roofing Specialists, we have seen the reality: spray foam insulation applied to the underside of roof tiles can be one of the most damaging alterations you can make to your home. In fact, our recent Facebook post described it as “every roofer’s worst nightmare” — and for good reason.

This blog will explain what spray foam insulation is, why it can cause devastating problems for your roof, what the official guidance says, and what to do if you already have it installed.

🧩 What is Spray Foam Insulation?

Spray foam insulation is made from liquid polyurethane, applied using a high-pressure spray. Once it hits a surface, it expands and hardens, forming a solid insulating layer.

It comes in two main types:

• Open-cell spray foam – softer, less dense, often used for internal walls.

• Closed-cell spray foam – denser, more rigid, commonly applied in lofts and roof spaces.

While it does insulate effectively, it seals surfaces completely, which is where the problems begin.

❌ Why Spray Foam Insulation is a Serious Problem for Roofs

1. Stops Ventilation and Traps Moisture

   
   

   Roof structures are designed to breathe. Traditional tiles, slates, and breathable membranes allow airflow to reduce condensation. Spray foam blocks this airflow, trapping moisture against rafters and timbers.

2. Creates Damp and Rot

   
   

   According to the National Federation of Roofing Contractors (NFRC), restricted airflow in roofs encourages condensation. Damp timbers quickly become breeding grounds for rot, mould, and fungal decay — compromising structural safety.

3. Conceals Roof Defects

   
   

   Spray foam bonds directly to tiles and felt, hiding leaks or cracks that would otherwise be visible. This means small roof problems can go unnoticed until they cause severe damage.

4. Invalidates Warranties and Insurance

   
   

   Many roofing warranties become void if spray foam is installed. Insurers may also refuse claims for roof damage, citing poor practice.

5. Blocks Proper Roof Inspections

   
   

   The Royal Institution of Chartered Surveyors (RICS) highlights that spray foam prevents surveyors from inspecting the roof structure properly. As a result, properties with spray foam often struggle to secure mortgages, remortgages, or sales.

6. Shortens Roof Lifespan

   
   

   A roof designed to last 60+ years can fail decades earlier if ventilation is restricted and rot takes hold.

7. Health Concerns

   
   

   Damp and mould caused by trapped moisture can lead to respiratory problems, particularly in children, the elderly, or those with asthma.

   
   

📜 Official UK Guidance on Spray Foam Insulation

• Building Regulations (Approved Document C – Resistance to Moisture): Requires roof spaces to be ventilated to prevent condensation. Spray foam directly contradicts this principle.

• NFRC (National Federation of Roofing Contractors): Strongly advises against applying spray foam directly to the underside of roof coverings.

• RICS Guidance: Advises lenders and surveyors to treat spray foam as a “red flag” due to inspection difficulties and potential hidden damage.

• Mortgage Lenders: Many UK banks and building societies will not lend against properties with spray foam insulation unless it is removed and the roof structure is certified as sound.

  
  

💷 The Financial Impact of Spray Foam Insulation

1. Reduced Property Value

   
   

   Homes with spray foam insulation are often worth significantly less because lenders and buyers see it as a liability.

2. Mortgage Refusals

   
   

   A 2023 RICS surveyor update confirmed that most lenders now refuse mortgage approval if spray foam is present.

3. Expensive Removal

   
   

   Removal costs can run into thousands of pounds, depending on roof size and damage already caused.

4. Hidden Repair Bills

   
   

   If rot has set in, you may face additional timber replacement or even a full re-roof.

   
   

🛠 What To Do If You Already Have Spray Foam

If your roof has spray foam insulation, you’re not alone — and help is available.

Step 1: Book a Professional Roof Survey Our NVQ-qualified roofers at Advanced Roofing Specialists can inspect your roof, assess the extent of damage, and provide a full report.

Step 2: Plan Safe Removal Spray foam cannot simply be peeled away. Professional removal involves carefully detaching it from tiles, battens, and felt to avoid causing further harm.

Step 3: Replace with Safe Insulation Once the foam is removed, we can install compliant, breathable insulation systems that meet UK Building Regulations. Options include mineral wool or rigid insulation boards with breathable membranes.

Step 4: Restore Roof Ventilation Ensuring proper airflow is key to preventing future problems. We design solutions tailored to your property, from vented ridges to soffit vents.

🔨 Why Choose Advanced Roofing Specialists?

We are a Norfolk and Suffolk-based, NVQ-qualified roofing company with years of experience tackling spray foam issues.

• Trusted by homeowners and businesses: From small re-roofs to major projects like the Arc Cinema (Royalty) in Great Yarmouth.

• Customer-focused: As one client, Rowan Nichols, put it:

  
  

  “These guys are fantastic! Got me out of a pickle with a leaking flat roof just before a new kitchen was fitted. They even came out on a Sunday morning! Professional, competitive, and highly recommended.”

  
  

• Comprehensive services: From new roofing and flat roofing to fascias, guttering, lead work, skylights, and spray foam removal.

• 
  

📞 Get Help with Spray Foam Insulation Today

If you’re worried about spray foam in your roof, don’t wait until problems spiral into costly repairs.

Contact Advanced Roofing Specialists today for an honest assessment and expert solution.

• Phone: 07861 700195

• Website: www.advancedroofingspecialists.co.uk

• Areas Covered: Norfolk & Suffolk