Spray Foam vs Rockwool: 3 Myths About Spray Foam You Need to Know

Homeowners often face a big decision when it comes to insulation. The right choice can affect your home’s comfort, energy efficiency, and long-term savings. Here in Kingston, proper insulation is essential for keeping homes warm in winter and cool in summer. That’s why EcoComfort offers both spray foam and Rockwool, tailored to your home’s needs and budget.
Both options perform well, but many homeowners mistakenly believe Rockwool is the premium option. The truth? Spray foam offers superior performance and stands as the premium choice because of its unmatched air sealing and energy efficiency.
In this article, we’ll dispel the top three myths about spray foam insulation versus Rockwool and show why spray foam is the premium choice.

Myth1: Spray Foam is a Fire Hazard

Some homeowners think spray foam is dangerous because it’s “flammable” or can’t meet fire safety standards, while Rockwool is naturally fire-resistant.

The Truth:
Spray foam can absolutely meet all building code fire safety requirements when installed properly. As Bob from EcoComfort explains, spray foam meets all building code fire safety standards when installed with a protective coating. EcoComfort applies this fire-protective coating as part of every spray foam installation, ensuring your home is fully compliant. With this protective layer, spray foam achieves the necessary fire ratings for residential construction.

So while Rockwool is naturally non-combustible, spray foam isn’t a hazard when done right. It’s safe, certified, and approved for use in homes across Ontario.

Myth 2: Rockwool Seals Air Just as Well as Spray Foam

Some people believe Rockwool performs the same as spray foam when it comes to air sealing.

The Truth:
Rockwool is an excellent insulator, but it does not create an air barrier. Air can still move through gaps, cracks, and cavities, which means drafts and heat loss continue. Spray foam, on the other hand, expands to fill every space, creating a continuous air and vapor barrier in one application.

Real Example:
One Kingston homeowner recently upgraded his attached garage with spray foam to keep it warmer in the winter. By applying just 2″ of spray foam on the perimeter walls, he achieved a complete air seal, something traditional batt insulation can’t provide on its own. This seal boosted comfort and helped reduce energy loss, while also limiting moisture-related issues and drafts.

Myth 3: Rockwool is the Healthier, Greener Choice

Some homeowners perceive Rockwool as the more environmentally friendly and healthier option, which can create the misconception that spray foam is harmful to their home or the planet.

The Truth:
Both products have environmental considerations. Spray foam does release VOCs during installation, but these dissipate quickly when installed properly by professionals. Rockwool, on the other hand, can release dust and fibers during installation. So neither product is entirely impact-free.

And when it comes to sustainability? Recent government regulations have pushed all insulation products to become more eco-friendly. Today, spray foam and Rockwool have very similar carbon footprints, according to industry data. The idea that Rockwool is significantly “greener” simply isn’t true.

Why Spray Foam is the Premium Option

Both spray foam and Rockwool are reliable insulation options, but spray foam stands out as the premium choice for energy efficiency and comfort. Unlike traditional insulation, spray foam creates a continuous air seal that stops drafts, reduces energy loss, and helps your HVAC run more efficiently. For homeowners seeking the highest level of performance and long-term savings, spray foam is hard to beat.

Not sure which option is best for your home?

Our team has installed both spray foam and Rockwool in homes across Kingston, Belleville, and Brockville. We’ll assess your needs and recommend the right solution for your project.
Call us today at (343) 600-0380 or email us for a free quote.