Your home is where your heart is, and you naturally expect it to be comfortable and lively. But what if you neglect to include proper insulation? Are you battling the summer heat or winter chill?
Here’s an affordable and effective solution—fibreglass insulation. This inclusion in your house building’s insulation system can effectively maintain a comfortable indoor temperature, reducing energy bills while enhancing comfort. Read this blog to learn how fibreglass insulation can help create a more relaxed and cost-effective haven.
What is Fiberglass Insulation?
“Fiberglass” is a special combination of very fine glass fibres, typically embedded in a plastic matrix. During building insulation, it works by trapping air within its tiny glass fibres, which act as a barrier to the flow of heat and sound to penetrate. Most of the time, the glass fibres are made of recycled glass in an eco-friendly way.
Fiberglass is commonly available in the forms of batts, rolls, loose-fill, and rigid boards.
Fibreglass insulation typically has a high R-value. This indicates that it offers greater thermal resistance than many other materials. Also, they are budget-friendly options.
What is the R-Value in an Insulation System?
A building material’s thermal resistance is measured by its R-value. This will help to identify their insulating properties. The higher the R-value, the better the insulating values will be. Most of the time, the climate and thickness of the insulating material will factor into the R-values.
The following are some examples of different thicknesses of fiberglass insulation along with their suitability for specific building applications:
- R-13 (about 3.5 inches thick): Commonly used in wall cavities to provide adequate thermal resistance for most climates.
- R-19 to R-30 (6 to 10 inches thick): Suitable for attics, where greater insulation is needed to prevent heat loss or gain.
- R-38 (12 inches thick): Recommended for attics in colder climates, where higher thermal resistance is essential to maintain indoor temperatures and reduce heating costs.
While choosing the R-value, consider your local climate. Warmer regions may require lower R-values, while colder climates demand higher R-values to ensure sufficient insulation and energy savings. Always match the insulation’s R-value to local climate recommendations for optimal performance.
Types of Fiberglass Insulation
Fiberglass insulation material is available in the following forms:
Fiberglass Insulation Batts
- Fibreglass batt insulation can offer better thermal insulation with R-values ranging from R-8 to R-49.
- Batts are pre-cut panels that come in defined lengths and widths to speed up the installation process with standard wood and metal framing in attics, ceilings, floors and walls.
- Batt insulations are typically sized to fit standard framing spacings of 16 or 24 inches in the centre.
- Fibreglass batts are ideal for both new construction and renovations where the framing is exposed.
- This type of insulation resists fire, does not cause corrosion, and helps in reducing sound transmission.
- Batt insulations are popular due to their simple installation process and affordability, and they can be installed by DIYers or professionals with basic tools and safety equipment.
Fiberglass Insulation Rolls (Blanket Insulation)
- Fibreglass rolls, also known as blanket insulation, are long, continuous lengths of fibreglass that can be cut to fit any space.
- In the Indian market, fiberglass insulation rolls are usually supplied in lengths of 10 to 20 meters (approximately 33 to 66 feet), with standard widths of 1.2 meters (about 4 feet).
- They are well-suited for covering large areas such as attics or between floor joists, where long runs without breaks are required.
- Fibreglass insulation rolls are flexible and easy to cut, allowing for customization to suit irregular spaces.
Blown-in or Loose-Fill Fiberglass Insulation
- Blown-in, or loose-fill, fibreglass consists of small particles that will be filled using a blowing machine.
- This type of insulation gives excellent coverage, filling gaps and voids that batts or rolls might miss, and is often used in retrofit applications to improve energy efficiency.
- It is ideal for attics and hard-to-reach or irregularly shaped areas.
- However, professional installation is essential for effective insulation and optimal performance.
Rigid Fiberglass Boards
- Rigid fiberglass boards are made from glass fibers and a thermosetting resin. They come in different forms—flexible, semi-rigid, or fully rigid.
- These boards are mainly used for systems that run at cooler temperatures than the surrounding air, especially where a vapour barrier is important.
- Fiberglass insulation is cost-effective, lightweight, and offers high thermal efficiency. It also provides structural support, fire resistance (firestop), and sound control (acoustic dampening). The boards can be produced either plain or with a facing layer for added protection.
- Rigid fiberglass boards are high-density panels designed for specialized applications, such as roofs, exterior walls, ductwork, and some commercial buildings.
- These boards offer a higher R-value per inch compared to batts or rolls, making them suitable where space is limited but high insulation performance is required.
Each type is suited to specific applications. You need to select the best solution based on your specific needs and building conditions.
Key Benefits of Fiberglass Insulation
When you insulate your home, including fibreglass insulation products, you will experience the following benefits:
Cost-Effective: When compared to other insulation methods, fibreglass insulation products are widely available at a maximum number of home improvement stores. Also, they are budget-friendly, easy to install, suitable for DIY projects.
High Thermal Performance: Fiberglass insulation is an energy-effective thermal insulating option. Forming a thermal barrier, it keeps the home warm in winter and cool in summer. Thus, it reduces the strain on HVAC systems and lowers electricity bills.
Fire-Resistance: Fibreglass insulation products are naturally non-combustible and provide a degree of fire resistance. Thus, fibreglass insulation avoids the spread of flames in case of a fire emergency. This makes it invaluable for evacuation purposes and to limit property damage.
Soundproofing Qualities: Fibreglass insulation gives extra pros with excellent sound absorption. This will help to reduce noise transmission from one room to another.
Eco-Friendly: This type of insulation is safe for residents with allergies or respiratory sensitivities. Fibreglass insulation doesn’t trap allergens like dust mites, pollen, or mould spores compared to other insulation materials. This will help maintain good air quality inside your home.
Long-lasting With Minimal Maintenance: Fiberglass insulation lasts for a long time with minimal maintenance. Its durability ensures it retains its insulating effectiveness over the years without settling or sagging.
Step-wise Fiberglass Insulation Installation Guide
You can consider the installation of fibreglass insulation as a DIY project or work with professionals. The following are some essential guidelines to follow during installation:
Safety Precautions
Fibreglass insulation is an irritant to the skin, eyes, and lungs; thus, wear gloves, goggles and a proper respirator mask (not just a dust mask) to avoid skin allergies or respiratory problems. Consider wearing a hat to prevent sticking of fibres on your hair. Work in a ventilated area.
Tools & Materials Needed
Gather all required tools, such as a utility knife, straightedge, sturdy step ladder and measuring tape.
The key material (Fiberglass batts/rolls) with a staple gun (for batts) or insulation blower (for loose-fill).
Installation Process
Measure the Space: Always measure the required space where you need to install insulation material carefully before cutting fibreglass insulation. Include an extra inch for a snug fit between studs. You can cut fibreglass insulation products with sharp scissors or a utility knife.
Fit Between Studs or Joists: Fiberglass insulation is a delicate process, so be careful during installation. Don’t compress or overstuff the insulation, as this can reduce its effectiveness. Gently place the insulation into the required areas, allowing it to expand and fill the cavities naturally.
Working Around Obstacles: When installing fiberglass insulation around obstacles like electrical boxes, pipes, or ductwork, it’s important to ensure full coverage without gaps or compression:
- First, split the insulation batt in half lengthwise.
- Tuck one half behind the obstacle.
Place the other half in front, cutting as needed to fit around the object. - Ensure the insulation fits snugly, without leaving any gaps or pressing it too tightly.
For vertical obstructions, cut the fibreglass batt vertically:
- Fit one section on each side of the obstacle.
- This creates a tight seal and maintains the insulation’s effectiveness.
Seal Gaps: Use caulk or foam sealant to seal any gaps or cracks in the building envelope before installing insulation to maximize its effectiveness.
Cover with Vapor Barrier: In humid climates, you need to install vapour barriers along with fibreglass insulation in areas prone to high humidity (such as bathrooms or basements). Including vapour barriers helps prevent moisture buildup, protecting the insulation from damage and potential mould growth. You can take suggestions from professionals to determine whether a vapour barrier is required or not.
Blown-in Method: For attics or irregular spaces, use blown-in (loose-fill) fibreglass insulation. A blowing machine distributes the insulation evenly, filling cavities and covering hard-to-reach areas for comprehensive coverage. Professional installation is recommended for best results.
Common Mistakes to Avoid During Fiberglass Insulation Installation
Compressing insulation: Never compress the insulation or overstuff, as this reduces its effectiveness.
Leaving gaps: If you leave gaps or voids between batts or around obstacles, these gaps allow heat to bypass the insulation, a phenomenon known as thermal bridging, which significantly reduces the insulation’s effectiveness.
Skipping Vapour Barriers in Moist Areas: Fiberglass insulation can absorb water and lose its insulating effectiveness when exposed to excessive moisture. Water can also create a breeding ground for mould and mildew. The vapour barrier should be properly installed on the warm side of the insulation, and all seams should be sealed to prevent condensation and maintain indoor air quality.
Fiberglass vs. Other Insulation Types
| Feature | Fiberglass | Cellulose | Spray Foam (PUF) | Mineral Wool |
| Cost | ₹30–₹60/sq ft | ₹40–₹70/sq ft | ₹80–₹150/sq ft | ₹50–₹90/sq ft |
| R-Value | 2.9–3.8/in | 3.2–3.7/in | 6.0–7.0/in | 3.3–4.2/in |
| Installation | DIY/Professional | Professional Needed | Professional only | DIY/Professional |
| Fire Resistance | Good | Treated (fire-resistant) | Excellent | Excellent |
| Soundproofing | Good | Very Good | Excellent | Excellent |
Applications of Fiberglass Insulation
Interior and Exterior Walls: You can install these fibreglass products in stud cavities to achieve thermal and acoustic insulation.
Attics, Roofs, and Attic Floors: Loose-fill fibreglass is the best option. After being blown into attics, a continuous layer of insulation is created.
Cathedral Ceilings: Fibreglass batts or rolls can be installed between cathedral ceiling rafters for insulation.
Floors Between Joists: Fibreglass insulation is placed between the wooden beams (joists) under floors—especially in crawl spaces and basements. This helps keep heat from escaping and makes the floor warmer.
HVAC Systems Ductwork: It is also used to wrap around heating and cooling ducts (HVAC ducts). This keeps the air at the right temperature as it moves through the house and helps lower energy use. It also reduces noise from the system.
Basements and Crawl Spaces – Walls and Floors: In these below-ground areas, fibreglass insulation is added to walls and floors. It helps keep the space warm and dry by reducing heat loss and controlling moisture.
Fiberglass for insulation is one of the effective building insulation solutions in India. Always prioritise safety during the installation of fibreglass insulation. Proper insulation done right the first time is the most cost-effective way to improve your home’s energy efficiency and comfort. Whether you choose fibreglass insulation for a single room or your entire home, it’s better to consult experts like Brick & Bolt to ensure professional guidance.