Choosing the right insulation for your home feels like a big decision, doesn’t it? You want to be comfortable, save on energy bills, and make a smart investment. Two popular contenders often pop up: spray foam and fiberglass. While both aim to keep your home cozy, they work quite differently. Let’s break it down in simple terms.
Fiberglass: The Familiar Choice

You’ve probably seen fiberglass insulation – it’s often pink or yellow and looks a bit like cotton candy (though most certainly not edible!). It comes in pre-cut batts or rolls, and sometimes as loose-fill.
- Pros: Fiberglass is generally the more budget-friendly option upfront. It’s been around for ages, it’s non-combustible, and it offers decent thermal performance (R-value).
- Cons: It can be prone to air leaks if not perfectly installed, as air can move through it and around the edges of the batts. It can also lose insulating power if it gets damp or compressed, and it doesn’t create an airtight seal on its own.
Introducing Spray Foam: The Modern Sealant

Spray Polyurethane Foam (SPF), or spray foam, is a liquid insulation applied using special equipment. It expands rapidly upon application, filling every nook and cranny before hardening into a solid barrier. There are two main types: open-cell (spongier) and closed-cell (rigid and dense).
- Pros: Spray foam’s superpower is air sealing. By expanding into gaps, it creates a highly effective air barrier, stopping drafts dead in their tracks. This significantly boosts energy efficiency. Closed-cell foam, in particular, offers a very high R-value per inch, acts as a moisture barrier, and can even add structural strength.
- Cons: The main drawback is the higher initial cost compared to fiberglass. It also requires professional installation – this isn’t a DIY weekend project. Proper ventilation planning is also crucial when using spray foam.
So, What’s the Real Difference?
Think of it like this: Fiberglass slows down heat transfer, while spray foam stops both heat transfer and air movement.
- Air Sealing: Spray foam is the clear winner, creating an almost airtight seal.
- R-Value: Spray foam typically offers a higher R-value per inch, especially closed-cell.
- Moisture: Closed-cell spray foam resists water; fiberglass can absorb it.
- Installation: Fiberglass can be DIY, but spray foam needs experts like us at Pro Insulations.
- Cost: Fiberglass costs less upfront; spray foam costs more initially but often leads to greater long-term energy savings.
Making the Choice
Both insulation types have their place. Fiberglass might be suitable for standard wall cavities on a tighter budget. Spray foam excels in areas where air leaks are a major concern (like attics, crawl spaces, rim joists) or where maximizing R-value in limited space is key.
Feeling unsure? That’s perfectly okay! Every home is unique. The team here at Pro Insulations is passionate about helping homeowners find the perfect fit for their needs and budget. Give us a call – we’d love to chat about your project and provide a personalized recommendation!