Fibreglass Insulation
Fibreglass insulation is one of the most widely known insulation materials used in residential construction. While it is common in many homes, it is not always the preferred solution depending on building design, performance goals, and installation conditions.
This page provides an overview of fibreglass insulation to help homeowners understand how it works and where it is typically used.
What Is Fibreglass Insulation
Fibreglass insulation is a man-made thermal insulation composed of fine glass fibres. It is designed to slow heat transfer by trapping pockets of air within the material. Fibreglass insulation is lightweight, non-combustible, and commonly used in residential buildings
It is most often recognized by its soft, fibrous appearance and is commonly installed in attics and wall cavities.
A Brief History of Fibreglass Insulation
Fibreglass was first developed in the early 20th century and later adapted for use as insulation in residential construction. Its widespread adoption began in the mid-1900s, making it one of the most commonly used insulation materials in North America
Types of Fibreglass Insulation
Fibreglass insulation generally comes in two primary forms:
- Batt or blanket insulation
Pre-cut or rolled sections designed to fit between framing members. - Loose-fill fibreglass insulation
A blown-in form used to cover attic floors or fill cavities where uniform coverage is needed.
Each type has different installation characteristics and performance considerations.
Performance Considerations
Fibreglass insulation provides thermal resistance by trapping air, with R-values varying based on product type and installation depth. However, its effectiveness depends heavily on proper installation and consistent coverage.
Gaps, compression, or air movement through the material can reduce real-world performance, especially in older homes or irregular framing conditions
Advantages and Limitations
Fibreglass insulation offers several advantages:
- Widely available
- Non-combustible
- Cost-effective
- Can provide sound dampening
However, it also has limitations:
- Performance can drop if improperly installed
- Does not inherently provide air sealing
- Less effective in areas with complex framing or air leakage
Because of these factors, fibreglass insulation is not always the optimal solution for improving comfort or energy efficiency.
Choosing the Right Insulation Method
There is no single insulation solution that works best for every home. Building design, existing conditions, and performance goals all influence which insulation method is most appropriate.
In many cases, alternative insulation methods may provide better overall performance, especially when air sealing, moisture control, or retrofit conditions are involved.
Learn more about insulation services offered by Reitzel Insulation:
These options are commonly recommended depending on the specific application.
Fibreglass Insulation FAQ
Yes. Fibreglass insulation is still commonly found in many residential buildings, especially older homes.
No. While it can be suitable in some situations, other insulation methods may provide better performance depending on the application.
Fibreglass insulation does not act as an air barrier and relies on proper installation and additional air sealing measures.
Yes. Spray foam, cellulose, and other insulation systems are often used as alternatives depending on project requirements.
