Spray Foam vs. Fiberglass: Which Insulation Is Right for Your Home?

Insulation is one of the most important components in any home—yet it’s often overlooked. Whether you’re building a new house, tackling a home renovation, or just looking to make your existing space more energy-efficient, choosing the right type of insulation can save you serious money on energy bills and keep your home comfortable year-round.

Two of the most commonly used types of insulation are spray foam and fibreglass. While both serve the same purpose—keeping your home warm in the winter and cool in the summer—they work in very different ways, and the right one for you depends on your home, budget, and goals.

In this guide, we’ll compare spray foam insulation and fibreglass insulation in depth to help you decide which option is best for your home. Whether you’re a homeowner or a contractor working with Miss Her Insulation, this article will walk you through everything you need to know.

---

What Is Insulation, and Why Does It Matter?

Before we dive into the comparison, let’s take a moment to understand what insulation does.

Insulation reduces the transfer of heat between the inside and outside of your home. In the summer, it helps keep hot air out and cool air in. In the winter, it does the reverse, keeping warm air inside and the cold air at bay. It also:

• Reduces energy consumption

• Enhances indoor comfort

• Improves indoor air quality

• Helps with soundproofing

• Can increase your home’s resale value

A well-insulated home saves energy and money, and it can reduce wear and tear on your HVAC system.

---

Spray Foam Insulation: What You Need to Know

What is Spray Foam?

Spray foam insulation is a liquid that expands into a foam when applied, creating an airtight seal. It can be sprayed directly into walls, ceilings, crawl spaces, and attic floors.

There are two main types of spray foam:

• Open-cell spray foam: Lighter and more flexible, ideal for interior applications.

• Closed-cell spray foam: Denser, more rigid, and more moisture-resistant. Often used in basements or exterior walls.

Pros of Spray Foam

✅ Superior Air Sealing
Spray foam expands to fill every crack and crevice, creating a tight seal that minimizes air leakage.

✅ High R-Value
Spray foam has a much higher R-value per inch compared to fiberglass. Closed-cell spray foam can have an R-value of up to 7 per inch.

✅ Moisture Barrier
Closed-cell spray foam acts as both an insulator and a vapor barrier, helping to prevent mold growth.

✅ Long Lifespan
Once installed, spray foam lasts for decades without settling or losing effectiveness.

✅ Energy Efficiency
Because of its tight seal and high R-value, homes insulated with spray foam typically enjoy lower heating and cooling costs.

Cons of Spray Foam

❌ Higher Cost
Spray foam is more expensive upfront compared to fiberglass. However, it may offer more savings over time.

❌ Professional Installation Required
Due to its chemical makeup and application method, spray foam insulation must be installed by trained professionals like Miss Her Insulation.

❌ Potential Off-Gassing
Some spray foam products may emit fumes during installation. Proper ventilation and curing are essential.

---

Fiberglass Insulation: What You Need to Know

What is Fiberglass?

Fiberglass insulation is made of tiny glass fibers and is most commonly found in batts, rolls, or loose-fill form. It’s the traditional go-to for insulating homes in the United States.

Pros of Fiberglass

✅ Cost-Effective
Fiberglass is one of the most affordable insulation options on the market.

✅ Easy to Install
It can be DIY-installed if you follow safety protocols, though professional installation is always recommended for best results.

✅ Fire Resistant
Fiberglass doesn’t burn and is considered fire-retardant.

✅ Readily Available
Found at nearly every home improvement store, it’s easy to source and replace.

✅ Eco-Friendly Options
Many brands now offer fiberglass batts made from recycled glass.

Cons of Fiberglass

❌ Lower R-Value
Fiberglass has an R-value of about 2.9 to 3.8 per inch, which is significantly lower than spray foam.

❌ Prone to Air Leaks
Unlike spray foam, fiberglass does not seal gaps and cracks, allowing air to pass through.

❌ Moisture Issues
If fiberglass insulation gets wet, it loses effectiveness and can harbor mold.

❌ Can Settle Over Time
Fiberglass can sag or settle, especially in vertical walls, reducing its insulating power over time.

❌ Health Risks if Mishandled
Inhaling fiberglass particles or skin contact can cause irritation if proper protective gear isn’t used.

---

Side-by-Side Comparison Chart

---

How to Choose: Key Factors to Consider

When choosing between spray foam and fiberglass insulation, consider the following:

1. Your Budget

If you’re working with a tight budget and need a quick insulation solution, fiberglass may be the better option. But if you can afford a higher upfront investment for long-term gains, spray foam will save you more over time.

2. Your Climate

In areas with extreme temperatures, spray foam performs better due to its superior sealing and thermal resistance. If you live in a milder climate, fiberglass might be sufficient.

3. Where You’re Insulating

• Attics and Crawl Spaces: Spray foam is ideal due to hard-to-reach gaps and high heat loss.

• Interior Walls: Fiberglass is a cost-effective choice for sound dampening.

• Basements and Moist Areas: Closed-cell spray foam’s moisture resistance makes it a better fit.

4. Long-Term Goals

Are you planning to stay in your home for the long haul? Spray foam may offer better energy savings and less maintenance. If you’re renovating to sell, fiberglass could be more cost-efficient.

---

Why Professional Installation Matters

Both types of insulation benefit from professional installation—but spray foam especially demands expertise. A certified technician from Miss Her Insulation ensures:

• Proper mixing and application

• No missed spots or gaps

• Safe and clean installation

• Adherence to building codes and environmental guidelines

DIY fiberglass can seem easy, but poor installation can lead to compression, gaps, or even safety hazards. When in doubt, hire pros who know how to get it right the first time.

Spray Foam vs. Fiberglass: What Do the Experts Say?

At Miss Her Insulation, we’ve worked with hundreds of homeowners to improve their home comfort and energy efficiency. Here’s our general advice:

• For long-term energy efficiency and moisture control, spray foam is hard to beat. It offers airtight insulation and strong thermal resistance, making it a premium option for new construction or major renovations.

• For affordable upgrades or quick fixes, fibreglass gets the job done. It’s reliable, widely used, and effective when installed properly.

Final Verdict: Which One Is Right for You?

There’s no one-size-fits-all answer. The right insulation depends on your unique home, needs, and budget.

If you’re still unsure, schedule a free consultation with the experts at Miss Her Insulation. We’ll assess your home, listen to your goals, and recommend the best insulation strategy for maximum comfort and savings.

Also Visit…

FAQs

Q1: Is spray foam insulation worth the cost?
Yes, especially if you plan to stay in your home long-term. Spray foam can cut your energy bills significantly, often offsetting the higher upfront cost within a few years.

Q2: Can I install fibreglass insulation myself?
Technically, yes. Fibreglass is DIY-friendly, but for best results and safety, we recommend professional installation, especially for hard-to-reach or awkward areas.

Q3: How do I know which insulation I currently have?
Take a look in your attic or behind outlet covers. Fibreglass looks like fluffy pink or yellow rolls. Spray foam appears as a hardened, foamy substance. Not sure? Miss Her Insulation can inspect it for you.