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Can Insulation Get Wet?

by Craig on June 07, 2024

The Impact of Wet Insulation: A Comprehensive Guide for Homeowners


Maintaining a comfortable and energy-efficient home is crucial, and insulation plays a key role in achieving this. However, one often overlooked aspect of home maintenance is the condition of your insulation, especially after it gets wet. No, insulation should not get wet! Wet insulation can lead to numerous problems, affecting not only the thermal efficiency of your home but also your health and finances. In this blog, we will explore the consequences of wet insulation, the importance of proper insulation inspection to prevent wet insulation, and the steps to take if your insulation has been compromised by moisture.

Why Wet Insulation is a Problem

Loss of Thermal Performance

Insulation works by trapping air within its structure, which slows down heat transfer and helps maintain a stable indoor temperature. When insulation gets wet, the water replaces the air in these pockets, significantly reducing its insulating properties. This means your home could become less energy-efficient, leading to higher heating and cooling costs. Key types of insulation that can be affected by excess moisture include roof insulation batts, ceiling insulation batts, and underfloor insulation.


Physical Changes

Insulation materials like glass wool are designed to be light and fluffy to maximise their effectiveness. When these insulation materials get wet, they become compressed and lose their ability to return to their original form. Just as a soggy sandwich doesn't regain its initial texture after drying, wet insulation doesn’t bounce back to its original state once it has been soaked. This loss of fluffiness and air pockets from the affected insulation compromises its thermal performance, which can affect your home's comfort levels and energy bills.


Health Risks

Wet insulation poses significant health risks. Like most other types of wet material, moisture creates an ideal environment for mould and mildew to grow. This can lead to poor indoor air quality, which can cause respiratory issues, allergies, and other health problems. Additionally, wet insulation can harbour bacteria and other contaminants that further impact air quality.

Common Types of Insulation and Their Vulnerabilities

Understanding how different types of insulation react to moisture can help you take appropriate action. Here are a few common types:


Roof Insulation blanket

The roof insulation blanket is particularly vulnerable to water damage, especially during storms or roof leaks. If the roof blanket gets wet, it needs to be inspected and likely replaced to maintain its effectiveness.


Acoustic Insulation, Otherwise Known as Soundproof Insulation

Acoustic insulation, designed to reduce noise, can also suffer when wet. Its soundproofing qualities diminish, and like thermal insulation, it can become a breeding ground for mould.


Underfloor Insulation, Otherwise Known as Floor Insulation

Underfloor insulation can be affected by excess moisture in the ground or flooding. Wet underfloor insulation loses its thermal resistance and can contribute to dampness in your home's lower levels.


Ceiling Insulation Batts

Ceiling insulation can be particularly tricky because it’s out of sight. Unless you can tell you've got a leaking roof, water damage here often goes unnoticed until significant damage has occurred, affecting both ceiling insulation performance and structural integrity.


Reflective foil Insulation

Foil insulation typically performs well to help protect your home from water ingress. However, long-term saturation and submersion in water can impact the effectiveness of the reflective foil surface. Additionally, when exposed to moisture for extended periods, oxidation of the foil can occur leading to a loss in thermal resistance.

Steps to Take If Your Insulation Gets Wet

Not only does wet insulation, prevent your insulation from doing its job, large amounts of insulation hold excess moisture can lead to mould and structural damage, leading to more expensive costs to rectify. That's why addressing the issue timely, is a must. Here's what you should do if you suspect you have wet insulation.

Immediately inspect the affected area

After any event that could have caused water damage, such as a storm or plumbing leak, inspect your insulation as soon as it is safe to do so. Look for signs of water damage, such as staining, compression, or a musty smell.


Assess the damage of the wet material

Determine the extent of the damage. If only a small section of batts are wet, you might only need to replace those. However, if a larger area is affected, and there is clear structural damage, you might need to consider a more extensive replacement.


Replace Damaged Insulation

Wet insulation should be removed and replaced from the affected area promptly. This is not a job that can be postponed, as lingering moisture for an extended period of time can lead to mould growth and other long-term issues.


Professional Help

For extensive damage, consider bringing in professionals. Licenced builders and specialist companies have experts who can assess and replace your wet insulation to ensure it’s done correctly.

Preventing Wet Insulation

Whilst it is true in some situations, you cannot prevent wet insulation, especially when caused by storm damage or other natural disasters, there are some things you can do to prevent insulation from getting wet and subsequently damaged. 

Ensure Proper Storage and Installation of All Insulation Products

All insulation products regardless of the insulation material should be stored in their original packaging until they are ready to be installed. Ensure that insulation is installed during dry weather and that it is protected from moisture during the installation process.


Regularly Maintain Your Insulation

Regularly inspect areas prone to leaks, such as your roof and plumbing. Promptly address any issues to prevent water from reaching your insulation.


Ensure Adequate Ventilation in Your Home

Ensure that your home has proper ventilation, especially in areas like the roof space, basement, attic and any crawl spaces. Good ventilation can help prevent moisture buildup.


Use High-Quality Insulation Products

Invest in high-quality insulation products from reputable brands like Bradford Insulation, Kingspan Insulation, and Fletcher Insulation. These products are manufactured to high standards and are designed to withstand various environmental conditions better.

Long-term Implications of Neglecting Wet Insulation

Neglecting wet insulation can lead to several long-term issues:


Increased Energy Bills

Wet insulation loses its thermal efficiency, causing your heating and cooling systems to work harder, leading to increased energy bills.


Insulation Material Damage

Prolonged exposure to moisture can weaken structural elements of your home, such as timber beams and plasterboard, this can lead to costly repairs if left to progress for an extended period of time.


Health Risks of Wet Insulation

As mentioned, mould and mildew from wet insulation can pose serious health risks. Poor indoor air quality can lead to chronic respiratory issues and other health problems.

Don't Ignore Wet Insulation! Learn More About Insulation From Home Insulation Online!

Maintaining the integrity of your home’s insulation is crucial for comfort, energy efficiency, and health. If your insulation gets wet, it’s essential to act quickly to assess the damage and replace compromised materials. Regular insulation inspections and prompt maintenance can prevent many of the issues associated with wet insulation.


For more information or to purchase high-quality insulation products, consider shopping for insulation from We offer a wide range of insulation options, including roof insulation batts, underfloor insulation, and ceiling insulation batts. Protect your home and ensure it remains a comfortable, healthy place to live.